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Article
Publication date: 3 February 2021

S. Sarath and P. Sam Paul

A new cutting tool is always well-defined and sharp at the onset of the metal cutting process and gradually losses these properties as the machining process advances…

Abstract

Purpose

A new cutting tool is always well-defined and sharp at the onset of the metal cutting process and gradually losses these properties as the machining process advances. Similarly, at the beginning of the machining process, amplitude of tool vibrations is considerably low and it increases gradually and peaks at the end of the service period of the cutting tool while machining. It is significant to provide a corresponding real-time varying damping to control this chatter, which directly influences accuracy and quality of productivity. This paper aims to review the literature related to the application of smart fluid to control vibration in metal cutting and also focused on the challenges involved in the implementation of active control system during machining process.

Design/methodology/approach

Smart dampers, which are used as semi-active and active dampers in metal cutting, were reviewed and the research studies carried out in the field of the magnetorheological (MR) damper were concentrated. In smart materials, MR fluids possess some disadvantages because of their sedimentation of iron particles, leakage and slow response time. To overcome these drawbacks, new MR materials such as MR foam, MR elastomers, MR gels and MR plastomers have been recommended and suggested. This review intents to throw light into available literature which exclusively deals with controlling chatter in metal cutting with the help of MR damping methods.

Findings

Using an MR damper popularly known for its semi-active damping characteristics is very adaptable and flexible in controlling chatter by providing damping to real-time amplitudes of tool vibration. In the past, many researchers have attempted to implement MR damper in metal cutting to control vibration and were successful. Various methods with the help of MR fluid are illustrated.

Research limitations/implications

A new cutting tool is always well-defined and sharp at the onset of metal cutting process and gradually losses these properties as the machining process advances. Similarly, at the beginning of the machining process, amplitude of tool vibrations is considerably low and it increases gradually and peaks at the end of service period of cutting tool while machining. Application of MR damper along with the working methodology in metal cutting is presented, challenges met are analyzed and a scope for development is reviewed.

Practical implications

This study provides corresponding real-time varying damping to control tool vibration which directly influences accuracy and quality of productivity. Using an MR damper popularly known for its semi-active damping characteristics is very adaptable and flexible in controlling chatter by providing damping to real-time amplitudes of tool vibration.

Social implications

This study attempts to implement smart damper in metal cutting to control vibrations.

Originality/value

It is significant to provide corresponding real-time varying damping to control tool vibration which directly influences accuracy and quality of productivity.

Details

World Journal of Engineering, vol. 18 no. 3
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 14 December 2020

Lawrance G., P. Sam Paul and Varadarajan A.S.

In the internal turning process, tool life and work piece quality are greatly influenced by the generation of heat in the cutting zone. During machining, cutting fluids…

Abstract

Purpose

In the internal turning process, tool life and work piece quality are greatly influenced by the generation of heat in the cutting zone. During machining, cutting fluids are applied at the cutting zones to reduce heat generation and enhance tribological properties. However, in the boring process, cutting fluids cannot be applied at cutting zone properly, and wastage of cutting fluid is a threat to the ecology and personnel health. Hence, application of semisolid lubricant in the boring process is considered as an innovative technique for temperature reduction in cutting zone because of its eco-friendly system, which also has a higher ability of biodegradability. This paper aims to study the influence of semisolid lubricants comprising of grease,graphite, aluminium oxide in different composition applied at a tool–chip,tool–work interface using a semisolid lubricant applicator applied with varying pressure.

Design/methodology/approach

In the present study, the cutting performance during boring of AISI4340 steel is enhanced through the application of semisolid lubricant with different composition of grease, graphite and aluminium oxide applied at tool-work and tool-chip interface with varying pressure using semisolid lubricant applicator.

Findings

The results show that use of semisolid lubricant like grease, graphite and nano aluminium oxide at tool-chip interface with maximum pressure reduces cutting temperature, tool vibration, cutting force and surface roughness.

Originality/value

Reduce cutting temperature, tool vibration, cutting force and surface roughness.

Details

World Journal of Engineering, vol. 18 no. 3
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 29 July 2021

D.S. Shylu Sam and P. Sam Paul

In parallel sampling method, the size of the sampling capacitor is reduced to improve the bandwidth of the ADC.

Abstract

Purpose

In parallel sampling method, the size of the sampling capacitor is reduced to improve the bandwidth of the ADC.

Design/methodology/approach

Various low-power techniques for 10-bit 200MS/s pipelined analog-to-digital converter (ADC) are presented. This work comprises two techniques including parallel sampling and switched op-amp sharing technique.

Findings

This paper aims to study the effect of parallel sampling and switched op-amp sharing techniques on power consumption in pipelined ADC. In switched op-amp sharing technique, the numbers of op-amps used in the stages are reduced. Because of the reduction in the size of capacitors in parallel sampling technique and op-amps in the switched op-amp sharing technique, the power consumption of the proposed pipelined ADC is reduced to a greater extent.

Originality/value

Simulated the 10-bit 200MS/s pipelined ADC with complementary metal oxide semiconductor process and the simulation results shows a maximum differential non-linearity of +0.31/−0.31 LSB and the maximum integral non-linearity (of +0.74/−0.74 LSB with 62.9 dB SFDR, 55.90 dB SNDR and ENOB of 8.99 bits, respectively, for 18mW power consumption with the supply voltage of 1.8 V.

Details

Circuit World, vol. 47 no. 3
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 23 March 2020

Vimukth John, Shylu Sam, S. Radha, P. Sam Paul and Joel Samuel

The purpose of this work is to reduce the power consumption of KSA and to improve the PDP for data path applications. In digital Very Large – Scale Integration systems…

Abstract

Purpose

The purpose of this work is to reduce the power consumption of KSA and to improve the PDP for data path applications. In digital Very Large – Scale Integration systems, the addition of two numbers is one of the essential functions. This arithmetic function is used in the modern digital signal processors and microprocessors. The operating speed of these processors depends on the computation of the arithmetic function. The speed computation block for most of the datapath elements was adders. In this paper, the Kogge–Stone adder (KSA) is designed using XOR, AND and proposed OR gates. The proposed OR gate has less power consumption due to the less number of transistors. In arithmetic logic circuit power, delay and power delay products (PDP) are considered as the important parameters. The delays reported for the proposed OR gate are less when compared with the conventional Complementary Metal Oxide Semiconductor (CMOS) OR gate and pre-existing logic styles. The proposed circuits are optimized in terms of power, delay and PDP. To analyze the performance of KSA, extensive Cadence Virtuoso simulations are used. From the simulation results based on 45 nm CMOS process, it was observed that the proposed design has obtained 688.3 nW of power consumption, 0.81 ns of delay and 0.55 fJ of PDP at 1.1 V.

Design/methodology/approach

In this paper, a new circuit for OR gate is proposed. The KSA is designed using XOR, AND and proposed OR gates.

Findings

The proposed OR gate has less power consumption due to the less number of transistors. The delays reported for the proposed OR gate are less when compared with the conventional CMOS OR gate and pre-existing logic styles. The proposed circuits are optimized in terms of power, delay and PDP.

Originality/value

In arithmetic logic circuit power, delay and PDP are considered as the important parameters. In this paper, a new circuit for OR gate is proposed. The power consumption of the designed KSA using the proposed OR gate is very less when compared with the conventional KSA. Simulation results show that the performance of the proposed KSA are improved and suitable for high speed applications.

Article
Publication date: 1 June 2005

Li‐teh Sun

Man has been seeking an ideal existence for a very long time. In this existence, justice, love, and peace are no longer words, but actual experiences. How ever, with the…

Abstract

Man has been seeking an ideal existence for a very long time. In this existence, justice, love, and peace are no longer words, but actual experiences. How ever, with the American preemptive invasion and occupation of Afghanistan and Iraq and the subsequent prisoner abuse, such an existence seems to be farther and farther away from reality. The purpose of this work is to stop this dangerous trend by promoting justice, love, and peace through a change of the paradigm that is inconsistent with justice, love, and peace. The strong paradigm that created the strong nation like the U.S. and the strong man like George W. Bush have been the culprit, rather than the contributor, of the above three universal ideals. Thus, rather than justice, love, and peace, the strong paradigm resulted in in justice, hatred, and violence. In order to remove these three and related evils, what the world needs in the beginning of the third millenium is the weak paradigm. Through the acceptance of the latter paradigm, the golden mean or middle paradigm can be formulated, which is a synergy of the weak and the strong paradigm. In order to understand properly the meaning of these paradigms, however, some digression appears necessary.

Details

International Journal of Sociology and Social Policy, vol. 25 no. 6/7
Type: Research Article
ISSN: 0144-333X

Keywords

Article
Publication date: 1 May 1998

Brian H. Kleiner

Presents a special issue, enlisting the help of the author’s students and colleagues, focusing on age, sex, colour and disability discrimination in America. Breaks the…

5348

Abstract

Presents a special issue, enlisting the help of the author’s students and colleagues, focusing on age, sex, colour and disability discrimination in America. Breaks the evidence down into manageable chunks, covering: age discrimination in the workplace; discrimination against African‐Americans; sex discrimination in the workplace; same sex sexual harassment; how to investigate and prove disability discrimination; sexual harassment in the military; when the main US job‐discrimination law applies to small companies; how to investigate and prove racial discrimination; developments concerning race discrimination in the workplace; developments concerning the Equal Pay Act; developments concerning discrimination against workers with HIV or AIDS; developments concerning discrimination based on refusal of family care leave; developments concerning discrimination against gay or lesbian employees; developments concerning discrimination based on colour; how to investigate and prove discrimination concerning based on colour; developments concerning the Equal Pay Act; using statistics in employment discrimination cases; race discrimination in the workplace; developments concerning gender discrimination in the workplace; discrimination in Japanese organizations in America; discrimination in the entertainment industry; discrimination in the utility industry; understanding and effectively managing national origin discrimination; how to investigate and prove hiring discrimination based on colour; and, finally, how to investigate sexual harassment in the workplace.

Details

Equal Opportunities International, vol. 17 no. 3/4/5
Type: Research Article
ISSN: 0261-0159

Keywords

Article
Publication date: 1 April 1988

Paul Nieuwenhuysen

The following bibliography focuses mainly on programs which can run on IBM microcomputers and compatibles under the operating system PC DOS/MS DOS, and which can be used…

Abstract

The following bibliography focuses mainly on programs which can run on IBM microcomputers and compatibles under the operating system PC DOS/MS DOS, and which can be used in online information and documentation work. They fall into the following categories:

Details

The Electronic Library, vol. 6 no. 4
Type: Research Article
ISSN: 0264-0473

Article
Publication date: 1 February 2000

Yaw A. Debrah and Ian G. Smith

Presents over sixty abstracts summarising the 1999 Employment Research Unit annual conference held at the University of Cardiff. Explores the multiple impacts of…

10977

Abstract

Presents over sixty abstracts summarising the 1999 Employment Research Unit annual conference held at the University of Cardiff. Explores the multiple impacts of globalization on work and employment in contemporary organizations. Covers the human resource management implications of organizational responses to globalization. Examines the theoretical, methodological, empirical and comparative issues pertaining to competitiveness and the management of human resources, the impact of organisational strategies and international production on the workplace, the organization of labour markets, human resource development, cultural change in organisations, trade union responses, and trans‐national corporations. Cites many case studies showing how globalization has brought a lot of opportunities together with much change both to the employee and the employer. Considers the threats to existing cultures, structures and systems.

Details

Management Research News, vol. 23 no. 2/3/4
Type: Research Article
ISSN: 0140-9174

Keywords

Article
Publication date: 1 June 1999

George K. Chacko

Gives an in depth view of the strategies pursued by the world’s leading chief executive officers in an attempt to provide guidance to new chief executives of today…

9136

Abstract

Gives an in depth view of the strategies pursued by the world’s leading chief executive officers in an attempt to provide guidance to new chief executives of today. Considers the marketing strategies employed, together with the organizational structures used and looks at the universal concepts that can be applied to any product. Uses anecdotal evidence to formulate a number of theories which can be used to compare your company with the best in the world. Presents initial survival strategies and then looks at ways companies can broaden their boundaries through manipulation and choice. Covers a huge variety of case studies and examples together with a substantial question and answer section.

Details

Asia Pacific Journal of Marketing and Logistics, vol. 11 no. 2/3
Type: Research Article
ISSN: 1355-5855

Keywords

Article
Publication date: 11 December 2019

Paul Nunekpeku

Library automation is required in academic libraries to meet the dynamic demands of clients. This study aims to investigate the level of clients’ satisfaction of Sam Jonah…

Abstract

Purpose

Library automation is required in academic libraries to meet the dynamic demands of clients. This study aims to investigate the level of clients’ satisfaction of Sam Jonah library automation.

Design/methodology/approach

The study utilized the descriptive research design by using an exploratory case study research method. A disproportionate stratified random sampling was used to select 322 respondents (undergraduates, postgraduates and lecturers/researchers) who consented to participate in the study. Questionnaire and informal interview were used for the data collection.

Findings

The study showed that more than half of the clients of Sam Jonah library were moderately satisfied with the library’s automation. Clients mostly access internet/Wi-Fi and reference service. Patronage of the services including photocopying, borrowing of books (circulation), e-resources/academic databases, institutional repository, library website and the OPAC was not encouraging. Increase in user education was recommended to improve their usage.

Research limitations/implications

The study was limited to only one academic library, namely, Sam Jonah library of the University of Cape Coast, Ghana.

Originality/value

The study provides insight into a case study of satisfactory level of clients in accessing automated services of Sam Jonah Library to serve as a basis for further research.

Details

Digital Library Perspectives, vol. 36 no. 1
Type: Research Article
ISSN: 2059-5816

Keywords

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