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Innovations in Science Teacher Education in the Asia Pacific
Type: Book
ISBN: 978-1-78190-702-3

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Article
Publication date: 10 July 2017

Chaoran Liu, Yufeng Su, Jinzhao Yue, Junjie Wang, Weiwei Xia, Dongxue Li, Wen Wang, Pan Wang and Zhiyong Duan

A self-adaptive piston is designed for the compressional gas cushion press nanoimprint lithography system. It avoids the lube pollution and high wear of traditional piston.

Abstract

Purpose

A self-adaptive piston is designed for the compressional gas cushion press nanoimprint lithography system. It avoids the lube pollution and high wear of traditional piston.

Design/methodology/approach

The self-adaptive piston device consists of symmetrical piston bodies, piston rings and other parts. The two piston bodies are linked by a ball-screw. The locking nut adjusts the distance between two piston bodies to avoid the piston rings from being stuck. The piston rings are placed between two piston bodies.

Findings

The simulation results based on COMSOL indicate that cylinder vibration caused by self-adaptive piston is 15.9 times smaller than the one caused by a traditional piston.

Originality/value

The self-adaptive piston is superior to the traditional piston in decreasing cylinder vibration.

Details

Industrial Lubrication and Tribology, vol. 69 no. 4
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 14 May 2018

Srinivasan Raghavan, Mui Ling Sharon Nai, Pan Wang, Wai Jack Sin, Tao Li and Jun Wei

The paper presents a wide range of post processing heat treatment cycles performed to Electron Beam Melted (EBM) Ti6Al4V alloy and establishes correlations of heat treat…

Abstract

Purpose

The paper presents a wide range of post processing heat treatment cycles performed to Electron Beam Melted (EBM) Ti6Al4V alloy and establishes correlations of heat treat process to microstructure and mechanical property (microhardness). The research also identifies the optimal heat treatment to obtain the best microstructure and mechanical properties (hardness and tensile).

Design/methodology/approach

Rectangular bars fabricated using EBM was used to study the different heat treatment cycles. A variety of heat treatments from sub ß-transus, super ß-transus, near ß-transus and solution aircool plus ageing were designed. After the heat treatment process, the samples were analysed for, α lath width, prior ß grain size, microhardness and nanohardness. Tensile tests were done for the heat treated samples showing most refined α lath structure with uniform globular grains.

Findings

A clear correlation was observed between α lath width and the microhardness values. The solution aircooled plus aged samples exhibited the best refinement in α-ß morphology with uniform equiaxed grains. The tensile properties of the solution aircooled plus aged samples were comparable to that of the EBM printed samples and better than ASTMF1472 specifications.

Originality/value

There is hardly any prior work related to post processing heat treatment of EBM built Ti6Al4V other than HIP treatments. The variety of heat treatment cycles and its influence in microstructure and properties, studied in this research, gives a clear understanding on how to tailor final microstructures and select the optimal heat treatment process.

Details

Rapid Prototyping Journal, vol. 24 no. 4
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 1 March 2012

Wen Wang and Zhirong Jerry Zhao

In recent decades, the responsibility for the financing of compulsory education in rural China has rested with townships and villages which, with limited tax authority and…

Abstract

In recent decades, the responsibility for the financing of compulsory education in rural China has rested with townships and villages which, with limited tax authority and uneven revenue capacity, increasingly relied on a plethora of arbitrarily imposed fees for funding. To reduce farmers’ fiscal burdens, in 2000, the central government installed a series of rural taxation reforms. Correspondingly, the central government shifted the administrative responsibilities of rural compulsory education to the county level in 2001, and implemented a series of policies to make up for the loss of revenues to education. Using a provincial-level dataset from 1998 to 2006, we examined whether and how the rural taxation reforms affected the adequacy and equity of compulsory education finance in China, addressing related theoretical and policy implications from the perspective of intergovernmental fiscal relations.

Details

Journal of Public Budgeting, Accounting & Financial Management, vol. 24 no. 1
Type: Research Article
ISSN: 1096-3367

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Article
Publication date: 7 August 2017

Jianming Zhang, Pan Wang, Chenjun Lu and Yunqiao Dong

The purpose of this paper is to preset a spherical element subdivision method for the numerical evaluation of nearly singular integrals in three-dimensional (3D) boundary…

Abstract

Purpose

The purpose of this paper is to preset a spherical element subdivision method for the numerical evaluation of nearly singular integrals in three-dimensional (3D) boundary element method (BEM).

Design/methodology/approach

In this method, the source point is first projected to the tangent plane of the element. Then two cases are considered: the projection point is either inside or outside the element. In both cases, the element is subdivided into a number of patches using a sequence of spheres with decreasing radius.

Findings

With the proposed method, the patches obtained are automatically refined as they approach the projection point and each patch of the integration element is “good” in shape and size for standard Gaussian quadrature. Therefore, all kinds of nearly singular boundary integrals on elements of any shape and size with arbitrary source point location related to the element can be evaluated accurately and efficiently.

Originality/value

Numerical examples for planar and slender elements with various relative location of the source point are presented. The results demonstrate that our method has much better accuracy, efficiency and stability than conventional methods.

Details

Engineering Computations, vol. 34 no. 6
Type: Research Article
ISSN: 0264-4401

Keywords

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Book part
Publication date: 3 August 2017

Matt Bower

Mobile devices, through their capacity to enable anytime-anywhere learning as well as capture, annotate and share multimedia, offer entirely new ways for students to…

Abstract

Mobile devices, through their capacity to enable anytime-anywhere learning as well as capture, annotate and share multimedia, offer entirely new ways for students to learn. This chapter provides review of mobile learning with a particular focus on learning design. First various definitions and characteristics of mobile learning are examined in order to establish a common understanding of its boundaries and meaning. Example uses of mobile learning in schools and higher education are described as a way to provide a more concrete understanding of design possibilities. Benefits of mobile learning are unpacked, as distilled from the literature, including the ability to provide flexible, accessible, authentic, personalized, ubiquitous and seamless learning. Mobile learning issues are also examined, including technical problems, cognitive load issues, distraction, equity and safety. A primary school science and a university pre-service teacher education vignette are described so as to offer a more in-depth illustration of what mobile learning can look like and achieve in practice. Finally, mobile learning research findings and observations are synthesized into recommendations, to inform and guide evidence-based mobile learning design practices. Opportunities for future research and investigation are also discussed.

Details

Design of Technology-Enhanced Learning
Type: Book
ISBN: 978-1-78714-183-4

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Article
Publication date: 1 August 2016

Jie Zhang, Mi Zuo, Pan Wang, Jian-feng Yu and Yuan Li

Design is a time-consuming process for mechanical production. Some design structures frequently occur in different products and can be shared by multiple assembly models…

Abstract

Purpose

Design is a time-consuming process for mechanical production. Some design structures frequently occur in different products and can be shared by multiple assembly models. Thus, identifying these structures and adding them to a design knowledge library significantly speed up the design process. Most studies addressing this issue have traditionally focused on part models and have not extended to assembly models. This paper aims to find a method for common design structure discovery in assembly models.

Design/methodology/approach

Computer-aided design models have a great deal of valuable information defined by different designers in the design stages, especially the assembly models, which are actually carriers of information from multiple sources. In this paper, an approach for discovering a common design structure in assembly models is proposed by comparing information from multiple sources. Assembly models are first represented as attribute connection graphs (ACGs), in which we mainly consider topological information and various attributes of parts and connections. Then, we apply a K-means clustering method based on a similarity analysis of different attributes to classify the parts and connections and transform ACGs of assemblies into type code graphs (TCGs). After this, a discovery algorithm that improves upon fast frequent subgraph mining is used to identify common design structures in assemblies.

Findings

A new method was developed for discovering common design structures in assembly models, considering the similarity of information from multiple sources and allowing some differences in the details to keep both commonalities and individualities of common design structures.

Practical implications

Experiments show that the proposed method is efficient and can produce a reasonable result.

Originality/value

This discovery method helps designers find common design structures from different assembly models and shorten the design cycle. It is an effective approach to build a knowledge library for product design that can shorten the design cycle.

Details

Assembly Automation, vol. 36 no. 3
Type: Research Article
ISSN: 0144-5154

Keywords

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Book part
Publication date: 9 March 2021

Hasan Dinçer, Serhat Yüksel and Gülsüm Sena Uluer

The aim of the study is to evaluate role of trade war between the United States and China on oil price. For this purpose, global oil price and US trade balance with China…

Abstract

The aim of the study is to evaluate role of trade war between the United States and China on oil price. For this purpose, global oil price and US trade balance with China are selected as variables. In addition to this issue, monthly data of these variables for the periods between 1990 and 2019 are taken into consideration. In the evaluation process, both Engle–Granger cointegration and Toda–Yamamoto causality analysis are considered. The results of Engle–Granger cointegration analysis indicates that there is a ­relationship between trade war and oil prices. Nevertheless, according to the results of Toda–Yamamoto causality analysis, it is identified that trade war does not cause oil prices. While looking at these results, it is determined that trade war between the United States and China has an influence on the oil price changes. However, it is also understood that it is not the main factor of this volatility. Thus, it is recommended that in order to identify the main indicator of the oil price volatility, some different factors should also be taken into consideration.

Details

Global Tariff War: Economic, Political and Social Implications
Type: Book
ISBN: 978-1-80071-314-7

Keywords

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Article
Publication date: 3 April 2017

R. Askari, M.F. Ikram and S. H. Hejazi

Thermal conduction anisotropy, which is defined by the dependency of thermal conductivity on direction, is an important parameter in many engineering and research studies…

Abstract

Purpose

Thermal conduction anisotropy, which is defined by the dependency of thermal conductivity on direction, is an important parameter in many engineering and research studies such as the design of nuclear waste depositional sites. In this context, the authors aim to investigate the effect of grain shape in thermal conduction anisotropy using pore scale modeling that utilizes real shapes of grains, pores and throats to characterize petrophysical properties of a porous medium.

Design/methodology/approach

The authors generalize the swelling circle approach to generate porous media composed of randomly arranged but regularly oriented elliptical grains at various grain ratios and porosities. Unlike previous studies that use fitting parameters to capture the effect of grain–grain thermal contact resistance, the authors apply roughness to grains’ surface. The authors utilize Lattice Boltzmann method to solve steady state heat conduction through medium.

Findings

Based on the results, when the temperature field is not parallel to either major or minor axes of grains, the overall heat flux vector makes a “deviation angle” with the temperature field. Deviation angle increases by augmenting the ratio of thermal conductivities of solid to fluid and the aspect ratios of grains. In addition, the authors show that porosity and surface roughness can considerably change the anisotropic properties of a porous medium whose grains are elliptical in shape.

Originality/value

The authors developed an algorithm for generation of non-circular-based porous medium with a novel approach to include grain surface roughness. In previous studies, the effect of grain contacts has been simulated using fitting parameters, whereas in this work, the authors impose the roughness based on the its fractal geometry.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 27 no. 4
Type: Research Article
ISSN: 0961-5539

Keywords

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Article
Publication date: 30 October 2020

Xiuchen Wang, Zhe Liu, Long Wu, Yue Wang and Ying Su

The change rules of the shielding effectiveness (SE) of the sleeve has not been clarified, which leads to the lack of the basis for the design, manufacture and evaluation…

Abstract

Purpose

The change rules of the shielding effectiveness (SE) of the sleeve has not been clarified, which leads to the lack of the basis for the design, manufacture and evaluation of the electromagnetic shielding (EMS) clothing.

Design/methodology/approach

According to a simplified analysis model, a series of sleeve samples with different fabrics and styles are designed and manufactured. The SE of the sleeve is tested with the proposed special test method in a semi-anechoic chamber to analyze the influence of different factors on the SE of the sleeve.

Findings

The SE is greatly reduced about 60–90% after the fabric is manufactured into the sleeve. The larger the sleeve length is, the higher the peak value of the SE is. When the sleeve length is low, the SE value is easy to appear negative. As the cuff circumference increases, the SE of the sleeve will change with the frequency band. The influence of the cuff style on the SE of the sleeve mainly depends on the cuff width and style. The larger the cuff width is, the lower the overall SE of the sleeve is. The more wrinkles there are at the cuff, the better the SE of the sleeve is.

Originality/value

Our results provide a reference for the design, production and evaluation of the sleeve and the whole EMS clothing.

Details

International Journal of Clothing Science and Technology, vol. 33 no. 2
Type: Research Article
ISSN: 0955-6222

Keywords

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