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Article
Publication date: 27 November 2018

Mubing Yu, Xiaodong Yu, Xuhang Zheng, Hang Qu, Tengfei Yuan and Daige Li

This paper aims to describe a theoretical and experimental research concerning influence of recess shape on comprehensive lubrication performance of high speed and heavy…

Abstract

Purpose

This paper aims to describe a theoretical and experimental research concerning influence of recess shape on comprehensive lubrication performance of high speed and heavy load hydrostatic thrust bearing with a constant flow.

Design/methodology/approach

The lubrication performance of a hydrostatic thrust bearing with different recess shape under the working conditions of high speed and heavy load has been simulated by using computational fluid dynamics and finite volume method.

Findings

It is found that the comprehensive lubrication performance of a hydrostatic thrust bearing with circular recess is optimal. The results demonstrate that recess shape has a great influence on the lubrication performance of the hydrostatic thrust bearing.

Originality/value

The simulation results indicate that to get an improved performance from a hydrostatic thrust bearing with constant flow, a proper selection of the recess shape is essential.

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Article
Publication date: 10 August 2018

Xiaodong Yu, Xu Zuo, Chao Liu, Xuhang Zheng, Hang Qu and Tengfei Yuan

Hydrostatic thrust bearing is a key component of the vertical CNC machining equipment, and often results in friction failure under the working condition of high speed and…

Abstract

Purpose

Hydrostatic thrust bearing is a key component of the vertical CNC machining equipment, and often results in friction failure under the working condition of high speed and heavy load. The lubricating oil film becomes thin or breaks because of high speed and heavy load and it affects the high precision and stable operation of the vertical CNC machining equipment; hence, it is an effective way of avoiding friction failure for achieving the oil film shape prediction

Design/methodology/approach

For the hydrostatic thrust bearing with double rectangular cavities, researchers solve the deformation of the friction pairs in hydrostatic bearing by using the computation of hydrodynamics, elasticity theory, finite element method and fluid-thermal-mechanical coupled method. The deformation includes heat deformation and elasticity deformation, the shape of gap oil film is got according to the deformation of the friction pairs in hydrostatic bearing, and gets the shape of gap oil film, and determines the influencing factors and laws of the oil film shape, and achieves the prediction of oil film shape, and ascertains the mechanism of friction failure. An experimental verification is carried out.

Findings

Results show that the deformation of the rotational workbench is upturned along its radial direction under the working condition of high speed and heavy load. However, the deformation of the base is downturned along its radial direction and the deformation law of the gap oil film along the radius direction is estimated; the outer diameter is close but the inner diameter is divergent wedge.

Originality/value

The conclusion can provide a theoretical basis for the oil film control of hydrostatic thrust bearing and improve the stability of vertical CNC machining equipment.

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Article
Publication date: 11 September 2019

John Dadzie, Goran Runeson and Grace Ding

Estimates show that close to 90% of the buildings we will need in 2050 are already built and occupied. The increase in the existing building stock has affected energy…

Abstract

Purpose

Estimates show that close to 90% of the buildings we will need in 2050 are already built and occupied. The increase in the existing building stock has affected energy consumption thereby negatively impacting the environment. The purpose of this paper is to assess determinants of sustainable upgrade of existing buildings through the adoption and application of sustainable technologies. The study also ranks sustainable technologies adopted by the professionals who participated in the survey with an in-built case study.

Design/methodology/approach

As part of the overall methodology, a detailed literature review on the nature and characteristics of sustainable upgrade and the sustainable technologies adopted was undertaken. A survey questionnaire with an in-built case study was designed to examine all the sustainable technologies adopted to improve energy consumption in Australia. The survey was administered to sustainability consultants, architects, quantity surveyors, facility managers and engineers in Australia.

Findings

The results show a total of 24 technologies which are mostly adopted to improve energy consumption in existing buildings. A factor analysis shows the main components as: lighting and automation, heating, ventilation and air conditioning (HAVC) systems and equipment, envelope, renewable energy and passive technologies.

Originality/value

The findings bridge the gap in the literature on the adoption and application of sustainable technologies to upgrade existing buildings. The technologies can be adopted to reduce the excessive energy consumption patterns in existing buildings.

Details

Journal of Engineering, Design and Technology , vol. 18 no. 1
Type: Research Article
ISSN: 1726-0531

Keywords

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Article
Publication date: 1 August 2010

Halimahton Binti Borhan and Elsadig Musa Ahmed

This study aims to examine the relationship between economic growth and different indicators of air and water pollution in Malaysia. Air pollution indicators were assessed…

Abstract

This study aims to examine the relationship between economic growth and different indicators of air and water pollution in Malaysia. Air pollution indicators were assessed on a number of measures: carbon monoxide, sulphur dioxide (SO), nitrogen dioxide, ozone and particulate matter (PM) while water pollution indicators were evaluating on a number of measures: biochemical oxygen demand, cadmium and arsenic. The income level per capita gross domestic product per capita were measured from the year 1996 to 2006 quarterly. Being different from the study by Hung and Shaw (2004) and Shen (2006), this study estimates population density as an endogenous variable. It formulates a fourequation simultaneous model for empirical research. Testes for exogeneity with the Hausman test and estimates the simultaneity model using the two‐stages least squares method. The Environmental Kuznets Curve (EKC) hypothesis is supported in the cases of SO and PM, and there are several differences found between single polynomial equation estimators commonly used in EKC literatures and simultaneous equation estimators.

Details

World Journal of Science, Technology and Sustainable Development, vol. 7 no. 3
Type: Research Article
ISSN: 2042-5945

Keywords

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Article
Publication date: 2 October 2020

Jing Fang, Xiaowei Liu and Wen Guang Qu

Prior IT productivity research usually assumes constant returns on IT investment. This study suggests that the impact of IT investment on productivity may not be constant…

Abstract

Purpose

Prior IT productivity research usually assumes constant returns on IT investment. This study suggests that the impact of IT investment on productivity may not be constant but may change with the IT investment scale and over time. Specifically, we divide IT investment into commercial IT and in-house IT and investigate their changing impacts on industry labor productivity.

Design/methodology/approach

A model of the productivity impacts of commercial IT and in-house IT with changing effects of scale and over time is developed and empirically tested based on industry-level panel data from the US. Bureau of Economic Analysis (BEA).

Findings

The returns on commercial IT investment increase with scale but decrease over time, while the returns on in-house IT increase over time.

Originality/value

This study provides a new perspective for IT productivity research by investigating the changing productivity impacts of IT investment. It also suggests that commercial IT and in-house IT should be distinguished, as they have different impacts on productivity.

Details

Industrial Management & Data Systems, vol. 120 no. 11
Type: Research Article
ISSN: 0263-5577

Keywords

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Article
Publication date: 1 April 1977

Gordon Wills, Jacqueline Hodgson, Christine Pearce, Phil Phillips and David Walters

This Symposium reports on the opportunities available to those who take the initiative to introduce materials management approaches. It examines both the anticipate rates…

Abstract

This Symposium reports on the opportunities available to those who take the initiative to introduce materials management approaches. It examines both the anticipate rates of change and development of the underlying factors as well as the organisational implications they entail. A full bibliography of recent literature is provided. The predicted developments are derived from the findings of a Delphi Study in association with the Institute of Purchasing and Supply conducted by the author in 1976.

Details

International Journal of Physical Distribution, vol. 8 no. 1
Type: Research Article
ISSN: 0020-7527

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Article
Publication date: 24 July 2019

Fun Liang Chang and Yew Mun Hung

This paper aims to investigate the coupled effects of electrohydrodynamic and gravity forces on the circulation effectiveness of working fluid in an inclined micro heat…

Abstract

Purpose

This paper aims to investigate the coupled effects of electrohydrodynamic and gravity forces on the circulation effectiveness of working fluid in an inclined micro heat pipe driven by electroosmotic flow. The effects of the three competing forces, namely, the capillary, the gravitational and the electrohydrodyanamic forces, on the circulation effectiveness of a micro heat pipe are compared and delineated.

Design/methodology/approach

The numerical model is developed based on the conservations of mass, momentum and energy with the incorporation of the Young–Laplace equation for electroosmotic flow in an inclined micro heat pipe incorporating the gravity effects.

Findings

By inducing electroosmotic flow in a micro heat pipe, a significant increase in heat transport capacity can be attained at a reasonably low applied voltage, leading to a small temperature drop and a high thermal conductance. However, the favorably applied gravity forces pull the liquid toward the evaporator section where the onset of flooding occurs within the condenser section, generating a throat that shrinks the vapor flow passage and may lead to a complete failure on the operation of micro heat pipe. Therefore, the balance between the electrohydrodyanamic and the gravitational forces is of vital importance.

Originality/value

This study provides a detailed insight into the gravitational and electroosmotic effects on the thermal performance of an inclined micro heat pipe driven by electroosmotic flow and paves the way for the feasible practical application of electrohydrodynamic forces in a micro-scale two-phase cooling device.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 30 no. 2
Type: Research Article
ISSN: 0961-5539

Keywords

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Article
Publication date: 1 March 1992

John Conway O'Brien

A collection of essays by a social economist seeking to balanceeconomics as a science of means with the values deemed necessary toman′s finding the good life and society…

Abstract

A collection of essays by a social economist seeking to balance economics as a science of means with the values deemed necessary to man′s finding the good life and society enduring as a civilized instrumentality. Looks for authority to great men of the past and to today′s moral philosopher: man is an ethical animal. The 13 essays are: 1. Evolutionary Economics: The End of It All? which challenges the view that Darwinism destroyed belief in a universe of purpose and design; 2. Schmoller′s Political Economy: Its Psychic, Moral and Legal Foundations, which centres on the belief that time‐honoured ethical values prevail in an economy formed by ties of common sentiment, ideas, customs and laws; 3. Adam Smith by Gustav von Schmoller – Schmoller rejects Smith′s natural law and sees him as simply spreading the message of Calvinism; 4. Pierre‐Joseph Proudhon, Socialist – Karl Marx, Communist: A Comparison; 5. Marxism and the Instauration of Man, which raises the question for Marx: is the flowering of the new man in Communist society the ultimate end to the dialectical movement of history?; 6. Ethical Progress and Economic Growth in Western Civilization; 7. Ethical Principles in American Society: An Appraisal; 8. The Ugent Need for a Consensus on Moral Values, which focuses on the real dangers inherent in there being no consensus on moral values; 9. Human Resources and the Good Society – man is not to be treated as an economic resource; man′s moral and material wellbeing is the goal; 10. The Social Economist on the Modern Dilemma: Ethical Dwarfs and Nuclear Giants, which argues that it is imperative to distinguish good from evil and to act accordingly: existentialism, situation ethics and evolutionary ethics savour of nihilism; 11. Ethical Principles: The Economist′s Quandary, which is the difficulty of balancing the claims of disinterested science and of the urge to better the human condition; 12. The Role of Government in the Advancement of Cultural Values, which discusses censorship and the funding of art against the background of the US Helms Amendment; 13. Man at the Crossroads draws earlier themes together; the author makes the case for rejecting determinism and the “operant conditioning” of the Skinner school in favour of the moral progress of autonomous man through adherence to traditional ethical values.

Details

International Journal of Social Economics, vol. 19 no. 3/4/5
Type: Research Article
ISSN: 0306-8293

Keywords

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Article
Publication date: 1 February 1999

The following paper has been recognised by the referees as an excellent and systematic piece of market research which we believe will be of great interest to our readers…

Abstract

The following paper has been recognised by the referees as an excellent and systematic piece of market research which we believe will be of great interest to our readers. It is included in this section of the Journal because we believe it will be of more immediate interest and more relevant to current consumer behaviour than might have been implied by presenting it in the academic papers section.

Details

Journal of Fashion Marketing and Management: An International Journal, vol. 3 no. 2
Type: Research Article
ISSN: 1361-2026

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Article
Publication date: 16 June 2021

Chun Liu and Jingjing Yang

The purpose of this study is to explore how hotels evolve their dynamic capabilities to adjust their technology-based strategy to improve performance and to gain…

Abstract

Purpose

The purpose of this study is to explore how hotels evolve their dynamic capabilities to adjust their technology-based strategy to improve performance and to gain competitive productivity (CP) during the COVID-19 pandemic and in the aftermath.

Design/methodology/approach

In-depth interviews with hoteliers were conducted to unveil their dynamic capabilities amid the pandemic as regard adjustments and performance of self-service technology (SST)-based strategies. Thematic analysis was used to analyze the data.

Findings

Data analysis revealed four types of dynamic capabilities (i.e. sensing, learning, integrating and coordinating capabilities). Equipped with these capabilities, hotels made minor adjustments to their SST strategies. In general, during an economic downturn, hotels refrained from introducing new SSTs. SSTs introduced before the pandemic were used more frequently and received enhanced customer feedback. The findings further revealed that the factors influencing hotels’ application of SSTs before and after the outbreak of COVID-19 remained similar.

Originality/value

This is the first research integrating CP, dynamic capabilities and strategic management process to explain how hotels adjust technological strategies to recover in a suddenly changed environment. Such a framework enables scholars and practitioners from content-oriented and process-oriented perspectives to make quick but sound strategic management decisions in adapting to turbulent environments. This timely study enriches the expertise of using technology as a recovery strategy and contributes to future research on the practical application of SSTs and crisis management.

Details

International Journal of Contemporary Hospitality Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0959-6119

Keywords

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