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Article
Publication date: 13 March 2017

H. Siddhi Jailani, A. Rajadurai, B. Mohan and T. Sornakumar

Metal matrix composites (MMCs) are commonly used in many aerospace and industrial applications. MMCs possess significantly improved properties including high specific…

Abstract

Purpose

Metal matrix composites (MMCs) are commonly used in many aerospace and industrial applications. MMCs possess significantly improved properties including high specific strength, specific modulus, damping capacity and good wear resistance compared to unreinforced alloys. The purpose of this paper is to describe the tribological studies of Al-Si alloy–fly ash composites manufactured using powder metallurgy technique.

Design/methodology/approach

Al-Si (12 Wt.%) alloy–fly ash composites were developed using powder metallurgy technique. Al-Si alloy powder was used as matrix material, and the fly ash was used as reinforcement. The particle size of Al-Si alloy powder was in the range of 75-300 μm, and the fly ash was in the range of 1-15 μm. The friction and wear characteristics of the composites were studied using a pin-on-disc set up. The test specimen was mated against cast iron disc, and the tests were conducted with the loads of 10, 20 and 30 N, sliding speeds of 0.5, 1 and 1.5 m/s for a sliding distance of 2,000 m.

Findings

The effects of load and sliding speed on tribological properties of the base alloy and Al-Si alloy–fly ash composites pins on sliding with cast iron disc are evaluated. The wear rate of Al-Si alloy–fly ash composites is lower than that of base alloy, and it increases with increasing load and sliding speed. The coefficient of friction of Al-Si alloy–fly ash composites is increased as compared with base alloy.

Practical implications

The development of Al-Si alloy–fly ash composites produced by powder metallurgy technique will modernize the automobile and other industries because near net shape at low cost and good mechanical properties are obtained.

Originality/value

There are few papers available on the development and tribological studies of Al-Si alloy–fly ash composites produced by powder metallurgy technique.

Details

Industrial Lubrication and Tribology, vol. 69 no. 2
Type: Research Article
ISSN: 0036-8792

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Book part
Publication date: 4 May 2018

Khusrizal, Basyaruddin, R.D.H. Rambe and I. Setiawan

Purpose – The research was carried out in order to study the composition of minerals, content of total-K, total-Ca, total-Mg, and exchangeable of K, Ca, Mg in volcanish ash

Abstract

Purpose – The research was carried out in order to study the composition of minerals, content of total-K, total-Ca, total-Mg, and exchangeable of K, Ca, Mg in volcanish ash from Sinabung volcano eruption.

Design/Methodology/Approach – The volcanic ash material in amount of 5 kg was collected from the depth of 0–20 cm and 21–41 cm. Mineral composition was determined by using line counting method; total contents of K, Ca, and Mg were measured by HCl 1N extraction, and exchangeable of K, Ca, and Mg was measured by NH4OAc 1N pH 7.0 extraction.

Purpose – The results depicted in volcanic ash layer at the depth of 0–20 cm found some minerals such as plagioclase (34%), hypersthene (9%), augite (3%), hornblende/amphibole (5%), and volcanic glass (1%). These minerals were also found in different amounts at a depth of 21–41 cm. Hypersthene and amphibole were higher and augite was lower at a depth of 0–20 cm than 21–41 cm. The total content of K, Ca, and Mg was found to be 2.27%, 8.12%, and 2.28%, respectively, at a depth of 0–20 cm. The exchangeable of K, Ca, and Mg was found in an amount of 1.89 me/100 g, 20.71 me/100 g, and 1.62 me/100 g, respectively. The total content of K, Ca, and Mg was not available to plants but could potentially be as a source of plant nutrient after weathering while exchangeable form can be uptaken by plant directly.

Research Limitations/Implications – Based on the composition of the minerals, total, and exchangeable of K, Ca, and Mg that the material of volcanic ash, it could potentially be used as source of fertilizers.

Originality/Value – The composition of primary minerals contained in volcanic ash and to know the amount of elements K, Ca, and Mg-associated minerals either in total or exchange.

Details

Proceedings of MICoMS 2017
Type: Book
ISBN:

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Article
Publication date: 24 February 2020

Eric Asa, Monisha Shrestha, Edmund Baffoe-Twum and Bright Awuku

Environmental issues caused by the production of Portland cement have led to it being replaced by waste materials such as fly ash, which is more economical and safer for…

Abstract

Purpose

Environmental issues caused by the production of Portland cement have led to it being replaced by waste materials such as fly ash, which is more economical and safer for the environment. Also, fly ash is a material with sustainable properties. Therefore, this paper aims to focus on the development of sustainable construction materials using 100% high-calcium fly ash and potassium hydroxide (KOH)-based alkaline solution and study the engineering properties of the resulting fly ash-based geopolymer concrete. Laboratory tests were conducted to determine the mechanical properties of the geopolymer concrete such as compressive strength, flexural strength, curing time and slump. In phase I of the study, carbon nanotubes (CNTs) were added to determine their effect on the strength of the geopolymer mortar. The results derived from the experiments indicate that mortar and concrete made with 100% fly ash C require an alkaline solution to produce similar (comparable) strength characteristics as Portland cement concrete. However, it was determined that increasing the amount of KOH generates a considerable amount of heat causing the concrete to cure too quickly; therefore, it is notable to forming a proper bond was unable to form a stronger bond. This study also determined that the addition of CNTs to the mix makes the geopolymer concrete tougher than the traditional concrete without CNT.

Design/methodology/approach

Tests were conducted to determine properties of the geopolymer concrete such as compressive strength, flexural strength, curing time and slump. In Phase I of the study, CNTs were studied to determine their effect on the strength of the geopolymer mortar.

Findings

The results derived from the experiments indicate that mortar and concrete made with 100% fly ash C require an alkaline solution to produce the same strength characteristics as Portland cement concrete. However, it was determined that increasing the amount of KOH generates too much heat causing the concrete to cure too quickly; therefore, it is notable to forming a proper bond. This study also determined that the addition of CNTs to the mix makes the concrete tougher than concrete without CNT.

Originality/value

This study was conducted at the construction engineering and management concrete laboratory at North Dakota State University in Fargo, North Dakota. All the experiments were conducted and analyzed by the authors.

Details

Journal of Engineering, Design and Technology , vol. 18 no. 6
Type: Research Article
ISSN: 1726-0531

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Article
Publication date: 1 December 1998

I.V. Suresh, C. Padmakar, Prabha Padmakaran, M.V.R.L. Murthy, C.B. Raju, R.N. Yadava and K. Venkata Rao

The potential problems and their consequences due to fly ash disposal have been well studied around the world. Ash pond is a common available disposal facility for thermal…

Abstract

The potential problems and their consequences due to fly ash disposal have been well studied around the world. Ash pond is a common available disposal facility for thermal power plants. The pond ash is subjected to weathering and the ions present in ash migrate to the soil and subsequently to the ground water over a period of time. A study has been carried out at Vijayawada Thermal Power Station (VTPS), Andhra Pradesh, India, to monitor the ground water quality in order to determine the potential impact of ash ponds. It has been found that ground water quality is deteriorated due to the presence of fly ash ions (macro and micro such as Fe, Ca, Mg etc.) which were leached out from the ash up to some extent. The contamination is likely to increase in the case of toxic and other ions with the passage of time. The presence of vegetative cover and plant growth on the down stream slope and fly ash ponds which are covered by soil may effectively control the leaching of ions.

Details

Environmental Management and Health, vol. 9 no. 5
Type: Research Article
ISSN: 0956-6163

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Article
Publication date: 16 September 2013

S. Venkat Prasat and R. Subramanian

The purpose of this paper is to explore the use of fly ash and graphite particles as low cost reinforcing materials for improved wear resistance, enhanced mechanical…

Abstract

Purpose

The purpose of this paper is to explore the use of fly ash and graphite particles as low cost reinforcing materials for improved wear resistance, enhanced mechanical properties and reduction in density of hybrid composites.

Design/methodology/approach

The AlSi10Mg/fly ash/graphite (Al/FA/Gr) hybrid composite was synthesised by stir casting method. The dry sliding wear and friction behaviour of hybrid composites were studied using pin-on-disc machine by varying parameters like load and weight fraction of fly ash, and compared with the base metal alloy and aluminium-graphite composite. The tests were conducted with a constant sliding speed of 2 m/s and sliding distance of 2,400 m.

Findings

The hybrid composites exhibit higher hardness, higher tensile strength and lower density when compared to unreinforced alloy and aluminium-graphite composite. The incorporation of fly ash and graphite particles as reinforcements caused a reduction in the wear rate and coefficient of friction (COF) of the hybrid composites. The improvement in the tribological characteristics occured due to the load carrying capacity of hard fly ash particles and the formation of a lubricating film of graphite between the sliding interfaces. The wear rates and COF of unreinforced aluminium alloy and composites increase with an increase in the applied normal load. The wear rates and COF of hybrid composites decrease with an increase in the fly ash content. 9 wt.% fly ash and 3 wt.% graphite reinforced hybrid composite exhibited the highest wear resistance and lowest COF at all applied loads. Abrasive wear and delamination were dominant in the mild wear regime of aluminium alloy and composites. Due to subsurface deformation and crack propagation, plate-like wear debris were generated during delamination wear. In the severe wear regime, the dominant wear mechanism was adhesive wear with formation of transfer layers.

Practical implications

It is expected that these findings will contribute towards the development of lightweight and low cost aluminium products with improved tribological and mechanical properties.

Originality/value

The wear and friction data have been made available in this article for the use of Al/FA/Gr hybrid composites in tribological applications.

Details

Industrial Lubrication and Tribology, vol. 65 no. 6
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 11 June 2018

Shubham Raj, Amrendra Kumar Rai and Vasant G. Havanagi

Industrial wastes such as copper slag and fly ash are being generated in tons every year and disposed mainly by land fillings, resulting in wastage of useful land. Copper…

Abstract

Purpose

Industrial wastes such as copper slag and fly ash are being generated in tons every year and disposed mainly by land fillings, resulting in wastage of useful land. Copper slag in itself is a granular cohesionless sand-like material, while fly ash is highly pozzolanic. The purpose of this paper is to investigate copper slag and fly ash mixes with cement as stabilizer for their proper use in road construction.

Design/methodology/approach

Different trial mixes of copper slag and fly ash were tested for obtaining the optimum mix having maximum dry density. Cylindrical specimens were prepared using optimum mix with different proportion of cement (3, 6 and 9 per cent) and cured for period of 7, 14 and 28 days in desiccator. Several tests such as proctor test, unconfined compressive strength test, splitting tensile strength test and soaked CBR test were carried out.

Findings

After analyzing the variation of test results with varying cement content and curing period, maximum compressive strength of 10 MPa and maximum tensile strength of 1.5 MPa was found for specimen having 9 per cent cement content cured for a period of 28 days. It was concluded that copper slag and fly ash when mixed in optimum proportion and stabilized with 6 and 9 per cent cement can be effectively used as granular material in sub base and base layer of road pavement.

Originality/value

A typical flexible pavement section was designed and checked using IITPAVE software which gave desired results. This paper may add value in the areas of pavement design, waste utilization, etc.

Details

World Journal of Engineering, vol. 15 no. 3
Type: Research Article
ISSN: 1708-5284

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Article
Publication date: 14 September 2015

Hüsamettin Kus and Duran Altiparmak

– The purpose of this paper is to investigate the effect of fly ash content on the friction–wear performance of bronze-based brake lining material.

Abstract

Purpose

The purpose of this paper is to investigate the effect of fly ash content on the friction–wear performance of bronze-based brake lining material.

Design/methodology/approach

In this study, bronze-based brake linings containing 0-12 weight per cent fly ash were produced by the hot-pressing process. The friction-wear properties of the unreinforced bronze matrix brake lining material and fly ash reinforced samples were investigated using a Chase-type friction tester. The hardness and density of the samples were also determined. The microstructures and friction surfaces of the samples were examined using scanning electron microscopy.

Findings

The experimental results showed that the fly ash content significantly affects the friction-wear properties of the brake lining material. It was found that the friction coefficient increases with the increase in the fly ash content for the brake lining materials studied. Moreover, the mass losses in the wear test were lower for the brake linings containing over 4 weight per cent fly ash than unreinforced bronze-based lining material.

Originality/value

This study has proven to be useful in exploring fly ash particles as low cost reinforcing materials in improving the friction–wear performance of bronze-based brake lining material. In addition, the use of fly ash particles in the manufacture of brake lining materials contributes to reducing the production cost of brake linings and to a sustainable environment.

Details

Industrial Lubrication and Tribology, vol. 67 no. 6
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 20 June 2019

Ali Akbar Abbasian Arani, Ali Arefmanesh and Hamidreza Ehteram

The purpose of this paper is to recommend a validated numerical model for simulation the flue gases heat recovery recuperators. Due to fulfill of this demand, the…

Abstract

Purpose

The purpose of this paper is to recommend a validated numerical model for simulation the flue gases heat recovery recuperators. Due to fulfill of this demand, the influences of ash fouling characteristics during the transient/steady-state simulation and optimization of a 3D complex heat exchanger equipped with inner plain fins and side plate fins are studied.

Design/methodology/approach

For the particle dispersion modeling, the discrete phase model is applied and the flow field has been solved using SIMPLE algorithm.

Findings

According to obtained results, for the recuperator equipped with combine inner plain and side plate fins, determination of ash fouling characteristics is really important, effective and determinative. It is clear that by underestimating the ash fouling characteristics, the achieved results are wrong and different with reality.

Originality/value

Finally, the configuration with inner plain fins with characteristics of: di =5 mm, do = 6 mm, dg = 2 mm, dk = 3 mm and NIPFT = 9 and side plate fins with characteristics of: TF = 3 mm, PF = 19 mm, NSPF = 17·2 = 34, WF = 10 mm, HF = 25 mm, LF = 24 mm and ß = 0° is introduced as the optimum model with the best performance among all studied configurations.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 30 no. 5
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 4 March 2014

Aneela Qadeer, Humera Anwer, Talat Mahmood and Muhammad Abbas Bhutto

Nutritional and medicinal properties of black sesame seeds (Sesamum indicum) make it very valuable in traditional system of food. Minerals in Sesamum indicum play an…

Abstract

Purpose

Nutritional and medicinal properties of black sesame seeds (Sesamum indicum) make it very valuable in traditional system of food. Minerals in Sesamum indicum play an important role to enhance its nutritional value. The present research comprises on proximate and chemical analysis of Sesamum indicum. This study is also based on the development of ashing methods for extraction of metals in black sesame seeds. The paper aims to discuss these issues.

Design/methodology/approach

Black sesame seeds were taken from local market at Karachi-Pakistan. Proximate analysis of seeds comprises of moisture content, ash content and total metal content by EDTA titration. Digestion of this herb was done in different medium, i.e. HNO3, HCl, H2SO4 and simple ash (ash was prepared without using any acid). Atomic absorption spectroscopy was used for the analysis of metals, i.e. Fe, Zn, Cu and Mg in all these ashes.

Findings

From the results it is concluded that best medium for ashing is H2SO4, by which maximum ash (5.39±0.0021 per cent) produced. Qualitative analysis (based on Ksp values) also confirmed the presence of maximum number of metals in H2SO4 medium. Complexometric titration also revealed that maximum metal content was found to be in HCl and H2SO4 ash. Results from atomic absorption spectroscopy revealed that H2SO4 is the best method for copper (0.399±0.0001 mg/g) and iron (0.3993±0.0015 mg/g), while simple ash can extract zinc and magnesium at their maximum level.

Originality/value

This research demonstrates the best ashing method for the extraction of micronutrients, present in Sesamum indicum. These micronutrients are very beneficial for human health.

Details

Nutrition & Food Science, vol. 44 no. 2
Type: Research Article
ISSN: 0034-6659

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Article
Publication date: 15 June 2015

Ian Thomson, Colin Dey and Shona Russell

The purpose of this paper is to provide theoretical and empirical insights into the effective use of external accounts by social activists in conflict arenas in order to…

Abstract

Purpose

The purpose of this paper is to provide theoretical and empirical insights into the effective use of external accounts by social activists in conflict arenas in order to bring about change.

Design/methodology/approach

This paper presents a longitudinal case study of Action on Smoking and Health UK (ASH) and their use of external accounts and other activist practices during the period 1999-2010. The authors explore these practices from the perspective of one organisation engaged in conflict arenas concerning the (un)acceptability of tobacco production, consumption and governance. The authors conduct the exploration based upon a dynamic conflict arena framework that attends to the range of external accounting and activist practices, tactical intentions and states of conflict used by ASH to confront the tobacco industry and bring about change in tobacco governance.

Findings

The study identifies the use of a diverse range of external accounts and other activist practices. This assemblage of practices was used to confront, counter-act and to co-operate with actors engaged in tobacco-related conflicts. The evidence suggests that the deployment of different types of external accounts by ASH was aligned to the context of the particular conflict arena involved, and was influenced by the strategy and engagement tactics of the activists and other actors, as well as power dynamics and acceptability of the tobacco governance in the conflict arena. Whilst ASH used different external accounts in specific episodes of activism, these individual accounts also contributed to an emerging holistic account of the unacceptable consequences of tobacco production, consumption and governance.

Originality/value

This study provides new theoretical and empirical insights into how external accounts can contribute to the problematisation of governance and development of social and environmental change agendas. The dynamic conflict arena framework developed in this paper creates new visibilities and possibilities for developing external accounting practices and for researching this fast-developing area of social and environmental accounting.

Details

Accounting, Auditing & Accountability Journal, vol. 28 no. 5
Type: Research Article
ISSN: 0951-3574

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