Research Outputs (Mechanical and Industrial Engineering)
https://hdl.handle.net/10500/2925
2024-03-28T18:10:03ZAn overview of torrefied bioresource briquettes: quality-influencing parameters, enhancement through torrefaction and applications
https://hdl.handle.net/10500/29652
An overview of torrefied bioresource briquettes: quality-influencing parameters, enhancement through torrefaction and applications
Waheed, M. A.; Akogun, O. A.; Enweremadu, C. C.
Abstract
In recent years, the need for clean, viable and sustainable source of alternative fuel is on the rampage in the global space due to the challenges posed by human factors including fossil induced emissions, fuel shortage and its ever-rising prices. These challenges are the major reason to utilize alternative source of energy such as lignocellulosic biomass as domestic and industrial feedstock. However, biomass in their raw form is problematic for application, hence, a dire need for torrefaction pre-treatment is required. The torrefaction option could ameliorate biomass limitations such as low heating value, high volatile matter, low bulk density, hygroscopic and combustion behaviour, low energy density and its fibrous nature. The torrefied product in powder form could cause air pollution and make utilization, handling, transportation, and storage challenging, hence, densification into product of higher density briquettes. This paper therefore provides an overview on the performance of torrefied briquettes from agricultural wastes. The review discusses biomass and their constituents, torrefaction pre-treatment, briquetting of torrefied biomass, the parameters influencing the quality, behaviour and applications of torrefied briquettes, and way forward in the briquetting sector in the developing world.
2022-11-28T00:00:00ZExperimental investigation into the effect of surface roughness and mechanical properties of 3D-printed titanium Ti-64 ELI after heat treatment
https://hdl.handle.net/10500/28355
Experimental investigation into the effect of surface roughness and mechanical properties of 3D-printed titanium Ti-64 ELI after heat treatment
Lebea, L.; Ngwangwa, H. M.; Desai, D.; Nemavhola, F.
Abstract
The initial stability after implantology is paramount to the survival of the dental implant, and the surface roughness of the implant plays a vital role in this regard. The characterisation of surface topography is a complicated branch of metrology, with a huge range of parameters available. Each parameter contributes significantly towards the survival and mechanical properties of three-dimensional printed specimens. The purpose of this paper is to experimentally investigate the effect of surface roughness of three-dimensional printed dental implants and three-dimensional printed dogbone tensile samples under areal height parameters, amplitude parameters (average of ordinates), skewness parameters and mechanical properties. During the experiment, roughness values were analysed, and the results showed that the skewness parameter demonstrated a minimum value of 0.59%. The three-dimensional printed dental implant recorded the arithmetic mean deviation of the assessed profile with a 3.4-mm diameter at 43.23% and the three-dimensional printed dental implant with a 4.3-mm diameter at 26.18%. Samples with a complex geometry exhibited a higher roughness surface, which was the greatest difficulty of additive manufacturing when evaluating surface finish. The results show that when the ultimate tensile stress decreases from 968.35 to 955.25 MPa, the arithmetic mean deviation increases by 1.4%, and when ultimate tensile stress increases to 961.18 MPa, the arithmetic mean deviation increases by 0.6%. When the cycle decreases from 262,142 to 137,433, the arithmetic mean deviation shows that less than a 90.74% increase in the cycle is obtained. For the three-dimensional printed dental implants, the higher the surface roughness, the lower the mechanical properties, ultimately leading to decreased implant life and poor performance.
2021-11-17T00:00:00ZAn Approach to Integrate Skills Development in Open Distance Learning (ODL) Environment: Part 2
https://hdl.handle.net/10500/26042
An Approach to Integrate Skills Development in Open Distance Learning (ODL) Environment: Part 2
Hlalele, TS; Mothibeli, PM; Sumbanyambe, S
ODL education has been developing rapidly in
Southern Africa recently. The system involves study that is
not limted by geographical boundaries and in practice tend
to extend knowledge beyond that is offered by contact or
tradional univeristies. At the University of South Africa
(UNISA), adoption of this method on theoretical knowledge
has been successful. The practical component has not been
effective, particularly in Electrical and Mechanical
Engineering Curriculum. This has resulted in high volume
of dropouts, contributed to unskilled graduates and
unemployment growth within the academic space. In this
paper, an emerging centered learner and a developed
centered learner method is proposed. These two methods
simulate unemployed and employed students who study
part-time at the university in their first entry level.
Employed are classified as developed centered learner
(DCL) and unemployed, newly matriculated, as emerging
centered learner (ECL). The results show a measure of
correlation between the two groups of students in their
learning method. Developed centered learner attained a
better pass-rate than an emerging centered learner. A
conclusion is made by drawing attention to the integration of
practical curriculum elements and lasting understanding of
theory in practice for ODL graduates.
2018-12-20T00:00:00ZSelection of a computerized maintenance management system for mechanical and industrial lab equipment of University of South Africa
https://hdl.handle.net/10500/25959
Selection of a computerized maintenance management system for mechanical and industrial lab equipment of University of South Africa
Pita, M.; Ramdass, K.
The research on which this article is based, sought a suitable computerized maintenance management system (CMMS) for use in the Mechanical and Industrial Engineering laboratories and workshop at the University of South Africa. The university plans to implement such a computerized maintenance management system, to keep track of past repairs, schedule future maintenance, and maintain a ready list of vendors or sources of parts. Currently, the department does not have a maintenance strategy or equipment history. The price of a product is an important factor when selecting a CMMS program. The recommended software will not place to great a stress on the departmental budget, is user friendly and can be used by two to five users.
2019-09-30T00:00:00Z