Technology has transformed education by providing access and opportunities for learning through online formats. Leadership education has not been left out in this transformation…
Abstract
Technology has transformed education by providing access and opportunities for learning through online formats. Leadership education has not been left out in this transformation as many higher education institutions offer online leadership courses and programs to college students. This case study’s primary purpose was to develop a fundamental understanding of the program characteristics of leadership programs offered fully online in higher education. The content analysis on 51 online academic leadership programs within 33 universities shows that these programs share similar characteristics in their goals, targeted student populations, and methods of engaging and supporting students in online leadership learning.
Xu Jia, Yang Ou Xiang, Hu Yuan Pei and Song Wei
The investigations could guide the structural design and fatigue life prediction of air-conditioning compressor valve plates.
Abstract
Purpose
The investigations could guide the structural design and fatigue life prediction of air-conditioning compressor valve plates.
Design/methodology/approach
The High-Cycle Fatigue (HCF) and Very-High-Cycle Fatigue (VHCF) behaviors of stainless steel used for air-conditioning compressor valve plates were investigated. Monotonic and cyclic loading conditions were designed to explore the fatigue responses according to the load characteristics of the structure.
Findings
The crack initiation can be observed as the arc-shaped cracks at both sides of specimens and Y-shaped crack bifurcation in the specimens. Moreover, the middle section and the cracks at both ends are not connected to the surface of the specimen. The stress-life results of the materials under two directions (vertical and horizontal) were provided to examine the difference in fatigue strength.
Originality/value
Monotonic and cyclic loading conditions were designed to explore the fatigue responses according to the load characteristics of the structure. Based on the experimental data, the results indicate that specimens under cyclic loading conditions could demonstrate better mechanical performance than static loadings.
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Feng Yang, Pei Hu, Fuguo Zhao and Cuihua Hu
The purposes of this paper is to propose a customer returns model in a dual-channel supply chain where a customer can return the purchased product to the retailer or the…
Abstract
Purpose
The purposes of this paper is to propose a customer returns model in a dual-channel supply chain where a customer can return the purchased product to the retailer or the manufacturer and obtain an equilibrium of selling prices and refund prices and the optimal profit when considering customer returns in the centralized and decentralized dual-channel supply chain.
Design/methodology/approach
This paper mainly uses the game theory technique to analyze the problem. The manufacturer and the retailer are vertically integrated in the traditional channel, and the results of the centralized dual-channel supply chain are obtained. Then, the Stackelberg game was adopted to analyze the decentralized dual-channel supply chain. Finally, the detailed numerical simulation is proposed to obtain straight-forward insights for the industrial managers.
Findings
The mathematic analysis used shows that the main findings of this paper are: in the centralized scenario, the retailer and the manufacturer will charge higher selling prices when they offer return policy, and the demand for each channel increases, which results in higher profit; and the price and refund price of the direct channel in the centralized and decentralized dual-channel are the same, respectively.
Originality/value
Most previous literatures highlight that return policy plays an important role in supply chain which considering one channel. But there is no study on the customer return policy in dual-channel supply chain. This paper is a further step to model the effects of customer returns policy on the pricing policy and optimize the profits in a dual-channel supply chain. This paper analyzes the pricing and refund strategies and gets an equilibrium in the centralized and decentralized dual-channel supply chain scenarios.
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Noel Scott, Brent Moyle, Ana Cláudia Campos, Liubov Skavronskaya and Biqiang Liu
The purpose of the paper is researching on the motion law of fiber in the vortex field inside the nozzle.
Abstract
Purpose
The purpose of the paper is researching on the motion law of fiber in the vortex field inside the nozzle.
Design/methodology/approach
A three-dimensional calculation model was established using the MVS861 (Muratec Vortex Spinning) air-jet vortex-spinning nozzle as the prototype, and the fluid–solid coupling calculation module in the finite element calculation software ADINA (Adina System) was used to numerically analyze the fiber-air flow two-phase coupling. At the same time, the effect of the air pressure at the nozzle on the two-phase flow is studied.
Findings
The results show that after the air flow ejected through the nozzle, a vortex field will be generated in the flow field to push the internal fiber to move toward the nozzle outlet in a wave motion; as the air pressure at the nozzle increases, the fiber movement period becomes shorter and the oscillation frequency becomes higher; increasing the air pressure at the spray hole can improve the working efficiency of fiber twisting and wrapping.
Originality/value
The research present an effective and feasible theoretical model and method for the motion law of fiber in the vortex field inside the nozzle based on ADINA fluid–structure coupling model.
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WE place this special Conference number in the hands of readers in the hope and belief that it will offer features of distinct interest which will increase the value and enjoyment…
Abstract
WE place this special Conference number in the hands of readers in the hope and belief that it will offer features of distinct interest which will increase the value and enjoyment of Brighton. There can be no doubt that the organizers of Library Association Conferences have endeavoured to surpass one another in recent years; almost always, it may be said, with success. Brighton, like Blackpool if in a rather different way, is a mistress of the art of welcome, and it will be long before another town can surpass her in the art. She is at her best in September when the great, and to some appalling, crowds of her promenades have thinned out a little. This year, then, librarians have an interesting time ahead; although, as we glance over the programme again, we fear that the outdoor and other pleasures we have subtly suggested will occur only fitfully. There will be so much to do in the way of business.
Dianyin Hu, Rongqiao Wang and Zhi Tao
A probabilistic‐based design for turbine disk at high temperature can quantify risk and thus identify areas of possible overdesign (conservatism). Moreover, the need for…
Abstract
Purpose
A probabilistic‐based design for turbine disk at high temperature can quantify risk and thus identify areas of possible overdesign (conservatism). Moreover, the need for cost‐effective designs has resulted in the development of probabilistic design to quantify the effects of these uncertainties so as to improve the reliability of the component. This paper aims to address these issues.
Design/methodology/approach
The flow for probabilistic design established through investigating traditional design methods of the turbine disk at high temperature is divided into the processes of crack initiation and crack growth to find important design inputs at each course, where the probabilistic design criterion has been built based on the deterministic criteria and successful experiences.
Findings
The probabilistic‐based design procedure has been demonstrated by taking the reliability design of crack initiation process for turbine disk as the example. The reliability analysis for the disk life after optimization analysis was completed by considering random parameters reflecting the uncertainties. The results showed there was a margin in design for disk life referred to as the probabilistic criterion. This measure was taken by redesigning the structure to reduce the disk's weight within the range of reliability.
Practical implications
The present study provides a method to design aero‐engine components based on probabilistic design for further research.
Social implications
Moreover, the present study provides a way to design structures based on probabilistic design.
Originality/value
It is proved that probabilistic‐based design could produce a lower weight turbine disk by integrating well‐proved deterministic design methods and tools with probabilistic design techniques while maintaining low failure probability.
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Guanchen Liu, Dongdong Xu, Zifu Shen, Hongjie Xu and Liang Ding
As an advanced manufacturing method, additive manufacturing (AM) technology provides new possibilities for efficient production and design of parts. However, with the continuous…
Abstract
Purpose
As an advanced manufacturing method, additive manufacturing (AM) technology provides new possibilities for efficient production and design of parts. However, with the continuous expansion of the application of AM materials, subtractive processing has become one of the necessary steps to improve the accuracy and performance of parts. In this paper, the processing process of AM materials is discussed in depth, and the surface integrity problem caused by it is discussed.
Design/methodology/approach
Firstly, we listed and analyzed the characterization parameters of metal surface integrity and its influence on the performance of parts and then introduced the application of integrated processing of metal adding and subtracting materials and the influence of different processing forms on the surface integrity of parts. The surface of the trial-cut material is detected and analyzed, and the surface of the integrated processing of adding and subtracting materials is compared with that of the pure processing of reducing materials, so that the corresponding conclusions are obtained.
Findings
In this process, we also found some surface integrity problems, such as knife marks, residual stress and thermal effects. These problems may have a potential negative impact on the performance of the final parts. In processing, we can try to use other integrated processing technologies of adding and subtracting materials, try to combine various integrated processing technologies of adding and subtracting materials, or consider exploring more efficient AM technology to improve processing efficiency. We can also consider adopting production process optimization measures to reduce the processing cost of adding and subtracting materials.
Originality/value
With the gradual improvement of the requirements for the surface quality of parts in the production process and the in-depth implementation of sustainable manufacturing, the demand for integrated processing of metal addition and subtraction materials is likely to continue to grow in the future. By deeply understanding and studying the problems of material reduction and surface integrity of AM materials, we can better meet the challenges in the manufacturing process and improve the quality and performance of parts. This research is very important for promoting the development of manufacturing technology and achieving success in practical application.
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Meysam Azimian, Mahdi Karbasian, Karim Atashgar and Golam Kabir
This paper addresses special reliability-centered maintenance (RCM) strategies for one-shot devices by providing fuzzy inferences system with the assumption that, to data, there…
Abstract
Purpose
This paper addresses special reliability-centered maintenance (RCM) strategies for one-shot devices by providing fuzzy inferences system with the assumption that, to data, there is no data available on their maintenance. As far as one-shot devices are concerned, the relevant data is inadequate.
Design/methodology/approach
In this paper, a fuzzy expert system is proposed to effectively select RCM strategies for one-shot devices. In this research: (1) a human expert team is provided, (2) spatial RCM strategies for one-shot devices and parameters bearing upon those strategies are determined, (3) the verbal variables of the expert team are transformed into fuzzy sets, (4) the relationship between parameters and strategies are designed whereupon a model is developed by MATLAB software, (5) Finally, the model is applied to a real-life one-shot system.
Findings
The finding of this study indicates that the proposed fuzzy expert system can determine the parameters affecting the choice of the appropriate one-shot RCM strategies, and a fuzzy inference system can help for effective decision making.
Originality/value
The developed model can be used as a fast and reliable method for determining an appropriate one-shot RCM strategy, whose results can be relied upon with a suitable approximation in respect of the behavior test. To the best authors’ knowledge, this problem is not addressed yet.
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A.A. Bahajaj, A.M. Asiri, A.M. Alsoliemy and A.G. Al‐Sehemi
The purpose of this paper is to evaluate the photochromic performance of photochromic compounds in polymer matrices.
Abstract
Purpose
The purpose of this paper is to evaluate the photochromic performance of photochromic compounds in polymer matrices.
Design/methodology/approach
The poly(methyl methacrylate) PMMA and epoxy resin doped with photochromic spirooxazine (SO) are prepared and the effects of ultraviolet (UV) irradiation are studied using spectrophotometer. The reversible reaction is effected using white light. Photochemical fatigue resistance of these films is also studied.
Findings
Irradiation of colourless 7′,8′‐dichloro‐1,3,3‐trimethylspiro[indoline‐2,3′‐[3H]benzo[b][1,4]oxazine] (SO) doped in PMMA and epoxy resin with UV light (366 nm) results in the formation of an intense purple‐red coloured zwitterionic photomerocyanine (PMC). The reverse reaction is photochemically induced by irradiation with white light. Photocolouration and photobleaching reactions follow a first‐order rate equation. It is found that photocoloration rate constant of (SO) in both matrices is almost the same, which is unexpected. On the other hand, the rate of photobleaching reaction of (PMC) in PMMA is twice slower than that in the epoxy resin. It seems that the presence of the two chlorine atoms at positions 7′ and 8′ of the benzooxazine moiety destabilise the PMC in epoxy resin film and results in speeding up the fading process compared to that in PMMA. SO doped in epoxy resin shows much better fatigue resistance than that doped in PMMA.
Research limitations/implications
The PMMA and epoxy resin polymers doped photochromic spirobenzooxazine described in this paper were prepared and studied. The principle of study established can be applied to any type of polymer or to any type of photochromic compounds.
Practical implications
The photochromic materials developed can be used for different applications, such as coatings and holography.
Originality/value
The method developed may be used to enhance the performance of photochromic materials.