Characterization of Botswana coal from two coal fields : Mabesekwa and Mmamabula to determine its coal rank
- Authors: Makoba, Mmoloki , Moalosi, Taboka , Agachi, Paul S. , Muzenda, Edison , Mamvura, Tirivaviri A.
- Date: 2020
- Subjects: Botswana coal , Characterization , XRD
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/463728 , uj:41396 , Citation: Makoba, M. et al. 2020. Characterization of Botswana coal from two coal fields : Mabesekwa and Mmamabula to determine its coal rank. , DOI:10.24193/subbchem.2020.2.20
- Description: Abstract: Coal samples from two different coal fields: Mabesekwa and Mmamabula were collected (with six seams from each coal field) to characterize using X-Ray diffractometer (XRD), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FT-IR) spectroscopy. Proximate and ultimate analysis are also given. Clay minerals kaolinite, pyrite, dolomite, siderite and calcite, and quartz were discovered. Comparing measurements of C, VM, GCV, MC and FC obtained from the samples with literature, Botswana coal identifies as lignite grade A coal suitable for applications in coal gasification and ammonia based fertilisers due to its high volatile matter and high reactivity of char. The paper looks to use different methods to analyse Botswana coal and recommend its potential applications based on literature.
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Dry sliding wear behavior of in-situ frabicated TiC particulate reinforced AA6061 aluminium alloy
- Authors: Selvam, J David Raja , Dinaharan, Isaac , Rai, Rajkumar S. , Mashinini, P. M.
- Date: 2019
- Subjects: FESEM , XRD , EBSD
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/398915 , uj:33230 , Citation: J. David Raja Selvam, I. Dinaharan, Rajakumar S. Rai & P. M. Mashinini (2019) Dry sliding wear behaviour of in-situ fabricated TiC particulate reinforced AA6061 aluminium alloy, Tribology - Materials, Surfaces & Interfaces, 13:1, 1-11, DOI: 10.1080/17515831.2018.1550971
- Description: Abstract: Aluminium alloy AA6061 reinforced with different mass fractions of (0, 2.5, 5, 7.5 & 10 weight percentage) TiC particles was fabricated by the in-situ reaction process. The in-situ synthesized aluminium matrix composite (AMCs) were examined using X-ray diffraction, field emission scanning electron microscope and electron backscatter diffraction. The results from the aforesaid tests revealed the formation of TiC particles. The in-situ formed particles were found to have a homogenous distribution, clear bonding and good interface with the aluminium alloy AA6061. The dry sliding wear test results revealed an improvement in wear performance of aluminium alloy AA6061 due to the presence of TiC particulate. Furthermore, the in-situ formed TiC particulates refined the grain structure. The in-situ formed TiC particles improved the load bearing ability of the AMCs. The wear mechanisms recorded during the wear test were ploughing and adhesion at lower load and delamination at higher load.
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Modification of the hydration products of hydrated cement paste by fly ash, β-cyclodextrin and fly ash-β-cyclodextrin composite
- Authors: Ikotun, B. D. , Mishra S. , Fanourakis, George C.
- Date: 2017
- Subjects: Fly ash , Cyclodextrin , XRD
- Language: English
- Type: Article
- Identifier: http://ujcontent.uj.ac.za8080/10210/385555 , http://hdl.handle.net/10210/241647 , uj:24907 , Citation: Ikotun, B.D., Mishra S. & Fanourakis, G.C. 2017. Modification of the hydration products of hydrated cement paste by fly ash, β-cyclodextrin and fly ash-β-cyclodextrin composite.
- Description: Abstract: Studies on the modification of the hydration products of fly ash (FA), β-cyclodextrin (β-CD) and fly ash-β-cyclodextrin (FA-β-CD) composite cement paste samples as hydration progressed were done using X-ray diffraction analysis, scanning electron microscopy and Fourier transform infrared spectroscopy. This paper investigates the effect of FA, β-CD and FA-β-CD composite on the hydration and pozzolanic reactions. It was evident from all the analyses that β-CD improved the hydration reaction from the 7 day hydration period, while improvement on pozzolanic reaction was revealed from the 28 day hydration period. The study contributed to the knowledge of FA performance as a composite with cyclodextrin and promoted the continued inclusion of FA in concrete.
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Synthesis and microstructure characterization of in situ formed of Al2O3-TiB2 AMCs particles on AA6061 aluminium matrix composites
- Authors: Philip, Vibin , Raja Selvam, J David , Rai, Rajakumar , Mashinini, P. M.
- Date: 2019
- Subjects: AMC , XRD , Al2O3-TiB2
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/398308 , uj:33151 , Citation: Philip, V. et al. 2019. Synthesis and microstructure characterization of in situ formed of Al2O3-TiB2 AMCs particles on AA6061 aluminium matrix composites.
- Description: Abstract: Please refer to full text to view abstract.
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