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Article

Sue Holttum

This paper aims to examine three recent papers on discrimination and exclusion that happen on a day-to-day basis in social interactions, known as micro-aggressions.

Abstract

Purpose

This paper aims to examine three recent papers on discrimination and exclusion that happen on a day-to-day basis in social interactions, known as micro-aggressions.

Design/methodology/approach

The author searched for recent papers on discrimination in the databases Psyc INFO and ASSIA. Three papers were selected addressing a common theme published within the past 24 months.

Findings

All three papers concern a US context. The first reports experiences of women with physical disabilities in relation to micro-aggressions. Based on focus groups with 30 women, micro-aggressions appear to be common and some cause considerable distress. The second paper reports experiences of 65 mental health peer support workers in a range of mental health services and finds micro-aggressions common for them too. The third paper goes beyond occurrence and type of micro-aggressions. Based on existing research, it proposes how members of marginalised racial groups can tackle micro-aggressions, whether they are the target, an ally or a bystander.

Originality/value

These papers show clear examples of micro-aggressions, making them easier to see. While the first two papers are each the first to document micro-aggressions for specific marginalised groups, the third paper is the first to bring together practical ways to tackle micro-aggressions in day-to-day life. There is potential for this to help bring about increased social inclusion and equity for a range of marginalised groups, and for a resultant benefit in the mental and physical well-being of many people.

Details

Mental Health and Social Inclusion, vol. 24 no. 4
Type: Research Article
ISSN: 2042-8308

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Article

Zhaowei Su, Rui Mu, Yonghui Cui, Hongda Zhu, Xuetian Li and Zhongcai Shao

The purpose of this paper is to prepare composite micro-arc oxide coatings with better wear resistance and corrosion resistance.

Abstract

Purpose

The purpose of this paper is to prepare composite micro-arc oxide coatings with better wear resistance and corrosion resistance.

Design/methodology/approach

A nickel powder composite micro-arc oxide film was prepared on the surface of the magnesium alloy by the method of organically combining ultra-fine Ni powder with micro arc oxidation film layer. In this experiment, the changes in the corrosion resistance and microstructure of the composite film layer after adding Ni powder were studied, and the effect of the addition of glycerin on the corrosion resistance of the film layer was analyzed.

Findings

The results show that the ultra-fine nickel powder was successfully prepared by the liquid phase reduction method, and the micro-arc oxidation process was modified under the optimal addition amount. The surface of the micro-arc oxide film made of ultra-fine nickel powder was found by SEM to have smooth surfaces and few holes. According to X-ray diffraction analysis, the phase composition of the micro-arc oxide film layer was Mg, Ni, NiSiO4, MgNi (SiO4) and Mg2SiO4. According to the results of electrochemical tests, the corrosion resistance of the micro-arc oxidation composite film layer was improved after the addition of ultra-fine Ni powder, the corrosion current was greatly reduced and the impedance has been improved. And after adding glycerin, the surface of the film layer becomes denser, and the corrosion resistance of the micro-arc oxide film is significantly improved.

Originality/value

Through this experimental research, a micro-arc oxide coating of powder composite magnesium alloy was successfully prepared. The corrosion resistance of the micro-arc oxidation film layer has been improved, and certain functions had been given to the micro-arc oxidation composite film, which has increased the application field of magnesium alloys.

Details

Anti-Corrosion Methods and Materials, vol. 67 no. 5
Type: Research Article
ISSN: 0003-5599

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Article

Marina de Almeida Cruz, Victor Silva Corrêa, Daniela Martins Diniz and Felipe Mendes Borini

The dynamic capabilities (DC) literature focuses primarily on top managers. Although recent studies have drawn attention to middle management's (MM) relevance, these…

Abstract

Purpose

The dynamic capabilities (DC) literature focuses primarily on top managers. Although recent studies have drawn attention to middle management's (MM) relevance, these professionals have not been the focus of much attention in the DC literature. The purpose of this paper is to investigate whether and how MM influences DC dimensions.

Design/methodology/approach

Through a qualitative strategy and case-study method, 13 MM professionals from four Brazilian companies embedded in competitive and dynamic contexts were investigated. The “micro-practices” approach was used to operationalize the DC construct.

Findings

The evidence shows that MM influences DC dimensions. This influence appears to emanate from 19 identified and named micro-practices.

Practical implications

By examining how micro-practices (micro-level) influence macro-level DC dimensions, this article raises the significance of including the micro-practices identified herein in management-training programs.

Originality/value

The first relates to the identification of micro-practices within the MM scope. The second relates to the association of micro-practices with management functions. The third relates to the association of micro-practices with DC dimensions. Thereby, this article highlights how DC work in organizations' daily activities. The fourth is the construction of a framework that demonstrates how to integrate the DC micro (micro-practices), meso (managerial functions) and macro (DC dimensions) scopes. Fifth, this paper affirms the emerging research stream that stresses MM's relevance for DC generation.

Details

Journal of Strategy and Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1755-425X

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Article

Mikyoung Kim, Doori Song and Ahnlee Jang

Drawing upon attribution theory, this study aims to examine how different types of product information sources (mainstream celebrities vs micro-celebrities) interact with…

Abstract

Purpose

Drawing upon attribution theory, this study aims to examine how different types of product information sources (mainstream celebrities vs micro-celebrities) interact with content type (experiential vs promotional) to influence consumer response toward native posts on social media (causal attributions and click intention).

Design/methodology/approach

A total of 134 adult Twitter users participated in a 2 (source type: mainstream celebrity vs micro-celebrity) × 2 (content type: experiential vs promotional) between-subjects online experimental design.

Findings

Results showed that for experiential native advertising, messages from a micro-celebrity generated more information-sharing attributions and less monetary gain attributions than those from a mainstream celebrity on social media. Moreover, the experiential native ads from a micro-celebrity elicited greater intention to click the URL than those from a mainstream celebrity. However, consumer response was similar for promotional native advertising regardless of message source. This study demonstrates that information-sharing attributions mediate the interaction effects of source type and content types on click intention.

Originality/value

This study contributes to the literature on native advertising by providing empirical evidence to highlight the effect of message source and content type on consumer response. This study shows that the success of native advertising depends on how consumers perceive the messages and content creators' intention to communicate.

Details

Internet Research, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1066-2243

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Article

Xiong Liang, Bing Li, Xiaoyu Wu, Hongyan Shi, Kun Zeng and Yatao Wang

The purpose of this paper is to present a method for ultrasonically molding polymer powder in a micro plastic part mold. In the method, a printed circuit board (PCB) in…

Abstract

Purpose

The purpose of this paper is to present a method for ultrasonically molding polymer powder in a micro plastic part mold. In the method, a printed circuit board (PCB) in which micro‐hole arrays are drilled is used as a micro cavity insert. With the utilization of ultrasonic vibration, the polymer powder, which is prefilled and compacted in a micro cavity, mutually generates great sliding friction heat so as to be rapidly plasticized and molded.

Design/methodology/approach

Micro carbide drill bits of which the diameters are 100.0 μm, 150.0 μm and 200.0 μm, respectively, are used for drilling the PCB to form a micro‐hole array insert. Next, two kinds of various ultra‐high molecule weight polyethylene (UHMW‐PE) powder with various grain diameters are directly filled into a charging barrel and a mold cavity with the micro‐hole array insert. Proper process parameters are set on ultrasonic plasticizing and molding equipment so that a molding test can be performed. The melt of UHMW‐PE can be rapidly filled into the cavity. Finally, micro‐column array plastic parts are successfully prepared.

Findings

The micro‐hole array PCB is a mold insert which is quite applicable for the ultrasonic molding of the powder in the mold. When a molding material is the coarse UHMW‐PE powder with the grain diameter of about 350 μm, the diameter replication rates of the micro‐column array plastic parts become good in order with the increased micro‐hole diameter of the PCB. When the fine UHMW‐PE powder with the grain diameter of about 80 μm is adopted, the diameter replication rates of the micro‐column array plastic parts become good in order with the decreased micro‐hole diameter of the PCB.

Originality/value

In this paper, the micro‐column array plastic parts with good replicability are successfully prepared by a technique for ultrasonically plasticizing and molding in the cavity. The technique can be applied to the fields of medical treatment, communication, optics, chemistry and so on, such as biological micro needle arrays, micro biological chips, optical memories, and micro chemical reaction chips.

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Article

K. Jeevan, G.A. Quadir, K.N. Seetharamu, I.A. Azid and Z.A. Zainal

To determine the optimal dimensions for a stacked micro‐channel using the genetic algorithms (GAs) under different flow constraints.

Abstract

Purpose

To determine the optimal dimensions for a stacked micro‐channel using the genetic algorithms (GAs) under different flow constraints.

Design/methodology/approach

GA is used as an optimization tool for optimizing the thermal resistance of a stacked micro‐channel under different flow constraints obtained by using the one dimensional (1D) and two dimensional (2D) finite element methods (FEM) and by thermal resistance network model as well (proposed by earlier researcher). The 2D FEM is used to study the effect of two dimensional heat conduction in the micro‐channel material. Some parametric studies are carried out to determine the resulting performance of the stacked micro‐channel. Different number of layers of the stacked micro‐channel is also investigated to study its effect on the minimum thermal resistance.

Findings

The results obtained from the 1D FEM analysis compare well with those obtained from the thermal resistance network model. However, the 2D FEM analysis results in lower thermal resistance and, therefore, the importance of considering the conduction in two dimensions in the micro‐channel is highlighted.

Research limitations/implication

The analysis is valid for constant properties fluid and for steady‐state conditions. The top‐most surfaces as well as the side surfaces of the micro‐channel are considered adiabatic.

Practical implications

The method is very useful for practical design of micro‐channel heat‐sinks.

Originality/value

FEM analyses of stacked micro‐channel can be easily implemented in the optimization procedure for obtaining the dimensions of the stacked micro‐channel heat‐sinks for minimum thermal resistance.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 15 no. 1
Type: Research Article
ISSN: 0961-5539

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Article

Hongyan Shi, Jiali Ning and Qiuxin Yan

The purpose of this paper is to calibrate the surface emissivity of micro drill bit and to investigate the effect of different drilling parameters on the temperature of…

Abstract

Purpose

The purpose of this paper is to calibrate the surface emissivity of micro drill bit and to investigate the effect of different drilling parameters on the temperature of micro drill bit in printed circuit board (PCB) micro drilling process.

Design/methodology/approach

The surface emissivity of micro drill bit was obtained by experiments. Analysis of variance (ANOVA) was applied in this study to analysis the effect of different drilling parameters on the temperature of micro drill bit in PCB micro hole drilling. The most significant influencing factor on micro drill bit temperature was achieved by ANOVA.

Findings

First, the surface emissivity of cemented carbide rod decreased from 0.4 to 0.32 slowly with temperature in the range of 50-220°C. Second, the most significant influencing factor on the micro drill bit temperature was spindle speed among the drilling parameters including spindle speed, retract rate and infeed rate.

Research limitations/implications

In this paper, the influence of roughness of black coating, carbide rod and micro drill bit on the surface emissivity calibration and the temperature measurement was not considered.

Originality/value

A new simple method has been presented to calibrate the surface emissivity of micro drill bit. Through calibrating the surface emissivity of micro drill bit, the temperature of micro drill bit can be measured accurately by infrared thermometry. Analyzing the influences of different drilling parameters on the temperature of micro drill bit, the mechanism of drilling parameters on drilling temperature is achieved. The basis for the selection of drilling parameters to improve the hole quality is enhanced.

Details

Circuit World, vol. 42 no. 2
Type: Research Article
ISSN: 0305-6120

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Article

Hongyan Shi, Hui Li and Shengzhi Chen

The purpose of this paper is to obtain the micro drill bit temperature field distribution in micro-drilling process and the temperature drop in retracting process with…

Abstract

Purpose

The purpose of this paper is to obtain the micro drill bit temperature field distribution in micro-drilling process and the temperature drop in retracting process with simulation software. Meanwhile, the key factors that affect the micro drill bit temperature will be obtained as well. The results can also be used to improve the accuracy in on-line drilling temperature measurement.

Design/methodology/approach

The purpose of this paper is to obtain the micro drill bit temperature field distribution in micro-drilling process and the temperature drop in retracting process with simulation software. Meanwhile, the key factors that affect the micro drill bit temperature will be obtained as well. The results can also be used to improve the accuracy in on-line drilling temperature measurement.

Findings

Micro drill bit high-temperature area mainly concentrates in the cutting edge and chisel edge. With the increase of spindle speed and feed speed, the micro drill bit highest temperature increased. The micro drill bit temperature drop rate reaches 20° in the micro-drilling retraction process with certain parameters. The micro drill bit highest temperature detected by an infrared camera is lower by 22° than that in real drilling. The simulation results can be used to guide the actual industrial production.

Originality/value

The simulation results can be applied to revise the temperature measurement by an infrared camera in the drilling process. Drilling experiments show that the simulation method is correct and has certain practical significance. The current temperature measurement method can satisfy most of the requirements of temperature measurements.

Details

Circuit World, vol. 41 no. 1
Type: Research Article
ISSN: 0305-6120

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Article

Lianyu Fu, Xueguang Li and Qiang Guo

The purpose of this paper is to present key points relating to the development of micro drill bits with high aspect ratios and to provide a solution for high aspect ratio…

Abstract

Purpose

The purpose of this paper is to present key points relating to the development of micro drill bits with high aspect ratios and to provide a solution for high aspect ratio hole drilling.

Design/methodology/approach

Based on the analysis of challenges in high aspect ratio hole drilling, key points for the development of micro drills bit with high aspect ratio are discussed. A design example of a micro drill bit with 0.3 mm diameter and a 7.2 mm flute length is presented. Experiments are conducted to verify the performance of the developed micro drill bit.

Findings

Helix angle, web thickness and flute land ratio are three key parameters that significantly influence the behaviour of micro drill bits with high aspect ratios. Large helix angle, web thickness and flute land ratio are beneficial in terms of improving the performance of high aspect ratio micro drill bits. Step drilling is essential to prevent drill breakage and to ensure smooth debris evacuation. Meanwhile, proper steps and drilling parameters are of great importance to complete high aspect ratio hole drilling.

Originality/value

The paper highlights key points relating to the development of micro drill bits with high aspect ratios that can provide a satisfactory solution for high aspect ratio micro drill bit design.

Details

Circuit World, vol. 36 no. 4
Type: Research Article
ISSN: 0305-6120

Keywords

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Article

Xiaohong Lu, FuRui Wang, Zhenyuan Jia and Steven Y. Liang

Cutting tool wear is known to affect tool life, surface quality, cutting forces and production time. Micro-milling of difficult-to-cut materials like Inconel 718 leads to…

Abstract

Purpose

Cutting tool wear is known to affect tool life, surface quality, cutting forces and production time. Micro-milling of difficult-to-cut materials like Inconel 718 leads to significant flank wear on the cutting tool. To ensure the respect of final part specifications and to study cutting forces and tool catastrophic failure, flank wear (VB) has to be controlled. This paper aims to achieve flank wear prediction during micro-milling process, which fills the void of the commercial finite element software.

Design/methodology/approach

Based on tool geometry structure and DEFORM finite element simulation, flank wear of the micro tool during micro-milling process is obtained. Finally, experiments of micro-milling Inconel 718 validate the accuracy of the proposed method for predicting flank wear of the micro tool during micro-milling Inconel 718.

Findings

A new prediction method for flank wear of the micro tool during micro-milling Inconel 718 based on the assumption that the wear volume can be assumed as a cone-shaped body is proposed. Compared with the existing experiment techniques for predicting tool wear during micro-milling process, the proposed method is simple to operate and is cost-effective. The existing finite element investigations on micro tool wear prediction mainly focus on micro tool axial wear depth, which affects size accuracy of machined workpiece seriously.

Originality/value

The research can provide significant knowledge on the usage of finite element method in predicting tool wear condition during micro-milling process. In addition, the method presented in this paper can provide support for studying the effect of tool flank wear on cutting forces during micro-milling process.

Details

Industrial Lubrication and Tribology, vol. 70 no. 8
Type: Research Article
ISSN: 0036-8792

Keywords

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