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Article
Publication date: 3 May 2011

Mohammad Asaduzzaman Chowdhury, Dewan Muhammad Nuruzzaman and Mohammad Lutfar Rahaman

The present paper aims to experimentally investigate the effect of external horizontal vibration on friction property of an aluminium disc sliding against stainless steel pin.

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Abstract

Purpose

The present paper aims to experimentally investigate the effect of external horizontal vibration on friction property of an aluminium disc sliding against stainless steel pin.

Design/methodology/approach

To do so, a pin‐on‐disc apparatus having facility of vibrating the test samples at horizontal direction was designed and fabricated. In the study, a dimensional analysis is done to correlate the friction coefficient of aluminium with sliding velocity, frequency and amplitude of vibration.

Findings

At 100 Hz frequency of vibration, it is seen that during the starting, value of friction coefficient is 0.39 which remains constant for few seconds then increases almost linearly up to 0.45 over a duration of 15 s of rubbing and after that it remains constant for the rest of the experimental time. Similar trends of behavior are observed for transverse vibration. These findings are in agreement with the findings of Chowdhury and Helali.

Originality/value

It is expected that the applications of these results will contribute to the improvement of different concerned mechanical systems.

Details

Industrial Lubrication and Tribology, vol. 63 no. 3
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 8 May 2018

M.M. Shahin, Mohammad Asaduzzaman Chowdhury, Md. Arefin Kowser, Uttam Kumar Debnath and M.H. Monir

The purposes of the present study are to ensure higher sustainability of journal bearings under different applied loads and to observe bearing performances such as elastic…

Abstract

Purpose

The purposes of the present study are to ensure higher sustainability of journal bearings under different applied loads and to observe bearing performances such as elastic strain, total deformation and stress formation.

Design/methodology/approach

A journal bearing test rig was used to determine the effect of the applied load on the bearing friction, film thickness, lubricant film pressure, etc. A steady-state analysis was performed to obtain the bearing performance.

Findings

An efficient aspect ratio (L/D) range was obtained to increase the durability or the stability of the bearing while the bearing is in the working condition by using SAE 5W-30 oil. The results from the study were compared with previous studies in which different types of oil and water, such as Newtonian fluid (NF), magnetorheological fluid (MRF) and nonmagnetorheological fluid (NMRF), were used as the lubricant. To ensure a preferable aspect ratio range (0.25-0.50), a computational fluid dynamics (CFD) analysis was conducted by ANSYS; the results show a lower elastic strain and deformation within the preferable aspect ratio (0.25-0.50) rather than a higher aspect ratio using the SAE 5W-30 oil.

Originality/value

It is expected that the findings of this study will contribute to the improvement of the bearing design and the bearing lubricating system.

Details

Industrial Lubrication and Tribology, vol. 70 no. 4
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 28 September 2010

Mohammad Asaduzzaman Chowdhury

The purpose of this paper is to investigate experimentally the effect of natural frequency of the experimental set‐up on wear rate of glass fiber‐reinforced plastic (GFRP).

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Abstract

Purpose

The purpose of this paper is to investigate experimentally the effect of natural frequency of the experimental set‐up on wear rate of glass fiber‐reinforced plastic (GFRP).

Design/methodology/approach

Experimental and dimensional analysis. A pin‐on‐disc apparatus having facility of vibrating the test samples at different directions, amplitudes and frequencies was designed and fabricated. The natural frequency of the set‐up was varied by adding dead loads of the set‐up from 0 to 50 kg. At each added load, the wear rate has been measured.

Findings

The presence of natural frequency of vibration indeed affects the wear rate considerably. The values of wear rate increase with the increase of natural frequency of vibration of the experimental set‐up. As the wear rate increases with increasing natural frequency of vibration, therefore, maintaining appropriate level of natural frequency vibration wear may be kept to some lower value to improve mechanical processes. The empirical formula of wear rate is derived from the dimensionless analysis. The wear rate obtained from the correlation shows better relationship with experimental results.

Practical implications

It is expected that the applications of these results will contribute to the improvement of different concerned mechanical systems and machines.

Originality/value

Considering the lack of correlation among wear rate, natural frequency of the experimental set‐up and other operating parameters, the present research was started to find out suitable correlation and a way of reducing wear rate by applying known natural frequency of vibration at a particular direction. Therefore, in this paper, an attempt is made to investigate the wear behavior of GFRP under natural frequency of the experimental set‐up. It is expected that the applications of these results will contribute to the improvement of different concerned mechanical systems.

Details

Industrial Lubrication and Tribology, vol. 62 no. 6
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 14 August 2009

Mohammad Asaduzzaman Chowdhury and Maksud Helali

The purpose of this paper is to present the frictional behaviour of composite materials under external horizontal vibration. Variation of friction coefficient is…

Abstract

Purpose

The purpose of this paper is to present the frictional behaviour of composite materials under external horizontal vibration. Variation of friction coefficient is investigated experimentally when mild steel pin slides on composite materials such as glass fiber reinforced plastic (GFRP) and cloth reinforced ebonite (commercially known as gear fiber).

Design/methodology/approach

A pin‐on‐disc apparatus having the facility of vibrating the test samples in a horizontal direction is designed and fabricated. Horizontal vibration is created along (longitudinal direction), and perpendicular (transverse direction) to, the sliding direction. The experimental set‐up has the facility to vary the amplitudes and frequencies of vibration while velocity of vibration is kept constant.

Findings

The relative frictional behaviour of these materials and their dimensional analysis are yet to be investigated. Therefore an attempt is made to investigate the relative frictional property of the GFRP and cloth reinforced ebonite (commercially known as gear fiber) and the results of these composite materials are analyzed by dimensional analysis under horizontal vibration.

Practical implications

It is expected that the applications of these results will contribute to the improvement of different concerned mechanical systems.

Originality/value

It can also be noted that there are no clear correlations between friction‐ and other vibration‐related operating parameters. Considering the above conclusion and lack of correlation, the paper meant to find out a suitable correlation and a way of observing the response of friction force by applying known frequency and amplitude of vibration in a particular direction. It is expected that the application of these results will contribute to the improvement of different concerned mechanical systems.

Details

Industrial Lubrication and Tribology, vol. 61 no. 5
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 27 September 2011

Mohammad Asaduzzaman Chowdhury, Dewan Muhammad Nuruzzaman, Khaled Khalil and Mohammad Lutfar Rahaman

Solid thin films have been deposited on stainless steel 314 (SS 314) substrates in a chemical vapor deposition (CVD) reactor at different flow rates of natural gas mostly…

Abstract

Purpose

Solid thin films have been deposited on stainless steel 314 (SS 314) substrates in a chemical vapor deposition (CVD) reactor at different flow rates of natural gas mostly methane (CH4). The purpose of this paper was to investigate experimentally the variation of thin film deposition rate with the variation of gas flow rate.

Design/methodology/approach

During experiment, the effect of gap between activation heater and substrate on the deposition rate has also been observed. To do so, a hot filament thermal CVD unit is used. The flow rate of natural gas varies from 0.5 to 2 l/min at normal temperature and pressure and the gap between activation heater and substrate varies from 4 to 6.5 mm.

Findings

Results show that deposition rate on SS 314 increases with the increase of gas flow rate. It is also seen that deposition rate increases with the decrease of gap between activation heater and substrate within the observed range. These results are analyzed by dimensional analysis to correlate the deposition rate with gas flow rate, surface roughness and film thickness. In addition, friction coefficient and wear rate of SS 314 sliding against SS 304 under different normal loads are also investigated before and after deposition. The obtained results reveal that the values of friction coefficient and wear rate are lower after deposition than that of before deposition.

Originality/value

In this study, thin film deposition rate on SS 314 was investigated using CVD. The obtained results were analyzed by dimensional analysis to correlate the deposition rate with gas flow rate, surface roughness and film thickness. The friction coefficient and wear rate of SS 314 were also examined before and after deposition.

Details

Industrial Lubrication and Tribology, vol. 63 no. 6
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 16 August 2011

Dewan Muhammad Nuruzzaman, Mohammad Asaduzzaman Chowdhury and Mohammad Lutfar Rahaman

The present paper seeks to report the effect of duration of rubbing on friction coefficient for different polymer and composite materials. Variations of friction…

Abstract

Purpose

The present paper seeks to report the effect of duration of rubbing on friction coefficient for different polymer and composite materials. Variations of friction coefficient and wear rate with the normal load are also investigated experimentally when stainless steel (SS 304) pin slides on different types of materials such as cloth‐reinforced ebonite (commercially known as gear fiber), glass fiber‐reinforced plastic (glass fiber), nylon and polytetrafluoroethylene (PTFE).

Design/methodology/approach

A pin on disc apparatus is designed and fabricated. During experiment, the rpm of test samples was kept constant and relative humidity was 70 percent.

Findings

Studies have shown that the values of friction coefficient depend on applied load and duration of rubbing. It is observed that the values of friction coefficient decrease with the increase of normal load for glass fiber, nylon and PTFE. Different trend is observed for gear fiber, i.e. coefficient of friction increases with the increase of normal load. It is also found that wear rate increases with the increase of normal load for all the materials. The magnitudes of friction coefficient and wear rate are different for different materials.

Practical implications

It is expected that the applications of these results will contribute to the design of different mechanical components of these materials.

Originality/value

Within the observed range of applied normal load, the relative friction coefficient and wear rate of gear fiber, glass fiber, nylon and PTFE are experimentally investigated.

Details

Industrial Lubrication and Tribology, vol. 63 no. 5
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 May 2009

Mohammad Asaduzzaman Chowdhury and Maksud Helali

The purpose of this paper is to investigate experimentally the effect of external vertical vibration on the friction property of mild steel, glass fiber‐reinforced plastic…

Abstract

Purpose

The purpose of this paper is to investigate experimentally the effect of external vertical vibration on the friction property of mild steel, glass fiber‐reinforced plastic and cloth‐reinforced ebonite.

Design/methodology/approach

A pin‐on‐disc apparatus having the facility of vibrating the test samples in a vertical direction was designed and fabricated. The experimental setup has the facility to vary the amplitudes and frequencies of vibration, while the velocity of vibration is kept constant. During the experiment, the frequency and amplitude of vibration were varied from 0 to 500 Hz and 0 to 200 μm, respectively. Studies have shown that the friction coefficient decreases with the increase of amplitude and frequency of vertical vibration for the above‐said materials. The rate of decrease of friction coefficient is different for different materials. The results of these materials are analyzed by dimensional analysis to correlate the friction coefficient with sliding velocity, frequency and amplitude of vibration. The experimental results are also compared with those available in the literature and simple physical explanations are provided.

Findings

It was found that reducing the friction coefficient of different materials was achieved by way of reducing the friction force by applying known frequency and vibration and correlating the friction coefficient with frequency, amplitude and sliding velocity.

Practical implications

The paper presents a way of reducing friction force by applying known frequency and vibration so that the mechanical process can be considerably improved (by considering the appropriate design of vibration).

Originality/value

The paper's originality lies in demonstrating the correlation among friction coefficient, amplitude, frequency and sliding velocity for different types of materials.

Details

Industrial Lubrication and Tribology, vol. 61 no. 3
Type: Research Article
ISSN: 0036-8792

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Book part
Publication date: 20 October 2015

Mohammad Shamsuddoha

Contemporary literature reveals that, to date, the poultry livestock sector has not received sufficient research attention. This particular industry suffers from…

Abstract

Contemporary literature reveals that, to date, the poultry livestock sector has not received sufficient research attention. This particular industry suffers from unstructured supply chain practices, lack of awareness of the implications of the sustainability concept and failure to recycle poultry wastes. The current research thus attempts to develop an integrated supply chain model in the context of poultry industry in Bangladesh. The study considers both sustainability and supply chain issues in order to incorporate them in the poultry supply chain. By placing the forward and reverse supply chains in a single framework, existing problems can be resolved to gain economic, social and environmental benefits, which will be more sustainable than the present practices.

The theoretical underpinning of this research is ‘sustainability’ and the ‘supply chain processes’ in order to examine possible improvements in the poultry production process along with waste management. The research adopts the positivist paradigm and ‘design science’ methods with the support of system dynamics (SD) and the case study methods. Initially, a mental model is developed followed by the causal loop diagram based on in-depth interviews, focus group discussions and observation techniques. The causal model helps to understand the linkages between the associated variables for each issue. Finally, the causal loop diagram is transformed into a stock and flow (quantitative) model, which is a prerequisite for SD-based simulation modelling. A decision support system (DSS) is then developed to analyse the complex decision-making process along the supply chains.

The findings reveal that integration of the supply chain can bring economic, social and environmental sustainability along with a structured production process. It is also observed that the poultry industry can apply the model outcomes in the real-life practices with minor adjustments. This present research has both theoretical and practical implications. The proposed model’s unique characteristics in mitigating the existing problems are supported by the sustainability and supply chain theories. As for practical implications, the poultry industry in Bangladesh can follow the proposed supply chain structure (as par the research model) and test various policies via simulation prior to its application. Positive outcomes of the simulation study may provide enough confidence to implement the desired changes within the industry and their supply chain networks.

Details

Sustaining Competitive Advantage Via Business Intelligence, Knowledge Management, and System Dynamics
Type: Book
ISBN: 978-1-78560-707-3

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Article
Publication date: 28 February 2020

Gazi Mahabubul Alam and Md. Abdur Rahman Forhad

Diploma Engineers (DE) mainly receive practical and skills-oriented education and training in the area of technical and vocational subjects from the polytechnic system…

Abstract

Purpose

Diploma Engineers (DE) mainly receive practical and skills-oriented education and training in the area of technical and vocational subjects from the polytechnic system. Globally, universities have limited DEs access to Higher Education (HE). Over the course of time, many countries have changed this situation, putting into place a decent qualification and policy framework that ensures higher education for deserving candidates. Lately, Technical and Vocational Education and Training (TVET) received special priority in developing countries, and Bangladesh is no exception to it, resulting in a massive growth of DE. This study, the first of its kind, examines the impact of this growth with a key focus on the inclusion of diploma engineers into higher education.

Design/methodology/approach

Given the differentiated nature of research questions, multiple techniques are used to collect the data. However, this research uses the qualitative method. Both secondary and primary data are used. While secondary data are collected by the Bangladesh Bureau of Educational Information and Statistics (BANBEIS), primary data are collected through interviews. With standard sets of admission questions, tests are conducted with two groups of students to draw a comparison.

Findings

The number of students studying at polytechnic institutes is increasing dramatically. The growth of public polytechnic institutes remains steady. Public counterparts respond to the demand by operating both day and night shifts. Many private polytechnics are also established. The size and infrastructure of private Polytechnics are relatively insignificant. However, the mushrooming private sector covers the increased demand. The curve of DE has been increased radically with a questionable competency by the contribution of both public and private polytechnics. Only one public university provides higher education to these DE.

Originality/value

A few reports have been published in the area of TVET by the development partners and the Government of Bangladesh. Only one journal article is published exploring the role of TVET on national development in Bangladesh. However, none cover the issue of access to university education for DE graduates.

Details

Higher Education, Skills and Work-Based Learning, vol. 11 no. 1
Type: Research Article
ISSN: 2042-3896

Keywords

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