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Volume 67 (2020): Issue 4 (December 2020)

Volume 67 (2020): Issue 3 (September 2020)

Volume 67 (2020): Issue 2 (June 2020)

Volume 67 (2020): Issue 1 (March 2020)

Volume 66 (2019): Issue 4 (December 2019)

Volume 66 (2019): Issue 3 (December 2019)

Volume 66 (2019): Issue 2 (June 2019)

Volume 66 (2019): Issue 1 (March 2019)

Volume 65 (2018): Issue 4 (December 2018)

Volume 65 (2018): Issue 3 (September 2018)

Volume 65 (2018): Issue 2 (September 2018)

Volume 65 (2018): Issue 1 (March 2018)

Volume 64 (2017): Issue 4 (December 2017)

Volume 64 (2017): Issue 3 (September 2017)

Volume 64 (2017): Issue 2 (July 2017)

Volume 64 (2017): Issue 1 (March 2017)

Volume 63 (2016): Issue 4 (December 2016)

Volume 63 (2016): Issue 3 (September 2016)

Volume 63 (2016): Issue 2 (July 2016)

Volume 63 (2016): Issue 1 (May 2016)

Journal Details
Format
Journal
eISSN
1854-7400
First Published
30 Mar 2016
Publication timeframe
4 times per year
Languages
English

Search

Volume 64 (2017): Issue 2 (July 2017)

Journal Details
Format
Journal
eISSN
1854-7400
First Published
30 Mar 2016
Publication timeframe
4 times per year
Languages
English

Search

3 Articles
Open Access

Reliability of system for precise cold forging

Published Online: 26 Aug 2017
Page range: 91 - 102

Abstract

Abstract

The influence of scatter of principal input parameters of the forging system on the dimensional accuracy of product and on the tool life for closed-die forging process is presented in this paper. Scatter of the essential input parameters for the closed-die upsetting process was adjusted to the maximal values that enabled the reliable production of a dimensionally accurate product at optimal tool life. An operating window was created in which exists the maximal scatter of principal input parameters for the closed-die upsetting process that still ensures the desired dimensional accuracy of the product and the optimal tool life. Application of the adjustment of the process input parameters is shown on the example of making an inner race of homokinetic joint from mass production. High productivity in manufacture of elements by cold massive extrusion is often achieved by multiple forming operations that are performed simultaneously on the same press. By redesigning the time sequences of forming operations at multistage forming process of starter barrel during the working stroke the course of the resultant force is optimized.

Keywords

  • cold foring
  • process reliability
  • product accuracy
  • tool life
  • FE simulation
Open Access

Measurement of company effectiveness using analytic network process method

Published Online: 26 Aug 2017
Page range: 103 - 110

Abstract

Abstract

The sustainable development of an organisation is monitored through the organisation’s performance, which beforehand incorporates all stakeholders’ requirements in its strategy. The strategic management concept enables organisations to monitor and evaluate their effectiveness along with efficiency by monitoring of the implementation of set strategic goals. In the process of monitoring and measuring effectiveness, an organisation can use multiple-criteria decision-making methods as help. This study uses the method of analytic network process (ANP) to define the weight factors of the mutual influences of all the important elements of an organisation’s strategy. The calculation of an organisation’s effectiveness is based on the weight factors and the degree of fulfilment of the goal values of the strategic map measures. New business conditions influence the changes in the importance of certain elements of an organisation’s business in relation to competitive advantage on the market, and on the market, increasing emphasis is given to non-material resources in the process of selection of the organisation’s most important measures.

Keywords

  • effectiveness
  • balanced scorecard
  • strategy management
  • analytic network process
Open Access

Physico-chemical trends in the sediments of Agbede Wetlands, Nigeria

Published Online: 26 Aug 2017
Page range: 111 - 126

Abstract

Abstract

This study assessed the physico-chemical status of sediments in the Agbede Wetlands with the aim to create a reference archive for the Edo North catchment and to further identify the characteristics mostly influenced by the natural and anthropogenic activities going on at the watershed. Nutrients, zinc, nickel and lead were identified to be mostly of anthropogenic origin, while alkali metals and alkaline earth metals were from both anthropogenic and natural sources. The clustering of stations 1 and 4 indicates that the sediment quality in the lentic systems was not completely excluded from the lotic system, suggesting that principal component analysis (PCA) and cluster analysis (CA) techniques are invaluable tools for identifying factors influencing the sediment quality. The mean values of the particle size distribution were in the following order across the ecosystems: sand (61.86–80.53%) > silt (9.75–30.34%) > clay (7.83–13.89%). The contamination of the water bodies was primarily derived from agricultural run-offs and through geochemical weathering of the top soils. Therefore, our analysis indicates that the concentrations of cations, anions and nutrients in the sediments of the lotic and lentic ecosystems in Agbede Wetlands are not at an alarming level.

Keywords

  • sediment
  • physico-chemical characteristics
  • pond
  • stream
  • principal component analysis
  • watershed
3 Articles
Open Access

Reliability of system for precise cold forging

Published Online: 26 Aug 2017
Page range: 91 - 102

Abstract

Abstract

The influence of scatter of principal input parameters of the forging system on the dimensional accuracy of product and on the tool life for closed-die forging process is presented in this paper. Scatter of the essential input parameters for the closed-die upsetting process was adjusted to the maximal values that enabled the reliable production of a dimensionally accurate product at optimal tool life. An operating window was created in which exists the maximal scatter of principal input parameters for the closed-die upsetting process that still ensures the desired dimensional accuracy of the product and the optimal tool life. Application of the adjustment of the process input parameters is shown on the example of making an inner race of homokinetic joint from mass production. High productivity in manufacture of elements by cold massive extrusion is often achieved by multiple forming operations that are performed simultaneously on the same press. By redesigning the time sequences of forming operations at multistage forming process of starter barrel during the working stroke the course of the resultant force is optimized.

Keywords

  • cold foring
  • process reliability
  • product accuracy
  • tool life
  • FE simulation
Open Access

Measurement of company effectiveness using analytic network process method

Published Online: 26 Aug 2017
Page range: 103 - 110

Abstract

Abstract

The sustainable development of an organisation is monitored through the organisation’s performance, which beforehand incorporates all stakeholders’ requirements in its strategy. The strategic management concept enables organisations to monitor and evaluate their effectiveness along with efficiency by monitoring of the implementation of set strategic goals. In the process of monitoring and measuring effectiveness, an organisation can use multiple-criteria decision-making methods as help. This study uses the method of analytic network process (ANP) to define the weight factors of the mutual influences of all the important elements of an organisation’s strategy. The calculation of an organisation’s effectiveness is based on the weight factors and the degree of fulfilment of the goal values of the strategic map measures. New business conditions influence the changes in the importance of certain elements of an organisation’s business in relation to competitive advantage on the market, and on the market, increasing emphasis is given to non-material resources in the process of selection of the organisation’s most important measures.

Keywords

  • effectiveness
  • balanced scorecard
  • strategy management
  • analytic network process
Open Access

Physico-chemical trends in the sediments of Agbede Wetlands, Nigeria

Published Online: 26 Aug 2017
Page range: 111 - 126

Abstract

Abstract

This study assessed the physico-chemical status of sediments in the Agbede Wetlands with the aim to create a reference archive for the Edo North catchment and to further identify the characteristics mostly influenced by the natural and anthropogenic activities going on at the watershed. Nutrients, zinc, nickel and lead were identified to be mostly of anthropogenic origin, while alkali metals and alkaline earth metals were from both anthropogenic and natural sources. The clustering of stations 1 and 4 indicates that the sediment quality in the lentic systems was not completely excluded from the lotic system, suggesting that principal component analysis (PCA) and cluster analysis (CA) techniques are invaluable tools for identifying factors influencing the sediment quality. The mean values of the particle size distribution were in the following order across the ecosystems: sand (61.86–80.53%) > silt (9.75–30.34%) > clay (7.83–13.89%). The contamination of the water bodies was primarily derived from agricultural run-offs and through geochemical weathering of the top soils. Therefore, our analysis indicates that the concentrations of cations, anions and nutrients in the sediments of the lotic and lentic ecosystems in Agbede Wetlands are not at an alarming level.

Keywords

  • sediment
  • physico-chemical characteristics
  • pond
  • stream
  • principal component analysis
  • watershed

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