scispace - formally typeset
Search or ask a question
Author

Oscar Asumani

Bio: Oscar Asumani is an academic researcher from University of the Witwatersrand. The author has contributed to research in topics: Kenaf. The author has an hindex of 1, co-authored 1 publications receiving 8 citations.
Topics: Kenaf

Papers
More filters
Journal ArticleDOI
TL;DR: The effects of two fibre treatments (alkali alone treatment and combined alkali-silane treatment) on the fatigue and impact strengths of kenaf fibre reinforced polypropylene composites are investigated in this paper.
Abstract: The effects of two fibre treatments (alkali-alone treatment and combined alkali-silane treatment) on the fatigue and impact strengths of kenaf fibre reinforced polypropylene composites are investig...

17 citations

Proceedings ArticleDOI
25 May 2022
TL;DR: In this paper , the authors investigate the behavior of cracks that develop in buried pipes, with the intent to provide the basis for the development of an engineering critical assessment (ECA) is relevant.
Abstract: Pipelines provide a critical function to the stability of chemical plant operations and transportation of fluids. The requirement for sound design and fabrication, inline inspections and maintenance are critical to reduce the risk of failure due to pre-existing or newly developed defects. Cracks can significantly impact the integrity of pipelines thus advanced inspection technologies, such as inline inspections, are important to identify the severity of the defect and implement an appropriate remediation action. Cracks act as stress concentration points from which the failure tends to initiate. Process upsets; such as pressure fluctuation, can cause a variation in the hoop stress levels, driving force for fatigue crack growth, which can lead to failure causing loss of containment, fires, or explosions. Existing cracks should be characterized to estimate residual life and hence safe operation based on the approach of damage tolerance. Currently, there is limited knowledge on the behaviour of cracks that develop in buried pipes. The geometry and orientation of these defects, operating conditions, external loading, and material properties affect the intensity of the propagation and arrest of cracks. Hence, an investigation into the behaviours of cracks with the intent to provide the basis for the development of an engineering critical assessment (ECA) is relevant.
Proceedings ArticleDOI
25 May 2022
TL;DR: In this article , a comparison between the estimated failure pressure based on the original ASME B31G equations and the modified version of B31Gs equations were compared to a finite element model based.
Abstract: Plant and feedstock stability is an important factor in ensuring consistent production volumes and minimal maintenance intervention, especially in the petrochemical industry. Thus, detailed design and in-line inspections of mid-stream equipment; such as underground pipelines are critical to reduce the risk of failure due to pre-existing or newly developed defects. Elongated external metal losses, assimilated to crack-like defects in some circumstances; can significantly impact the integrity of pipelines thus inline inspections are important to identify and implement remediation activities. ASME B31G provides guidelines to determine the estimated failure pressure in pipelines that have defects present. In this paper, a comparison between the estimated failure pressure based on the original ASME B31G equations and the modified ASME B31G equations were compared to a finite element model based.

Cited by
More filters
Journal ArticleDOI
07 May 2020-Polymers
TL;DR: Nanobiocomposites are exhibiting a higher market volume with the expansion of new technology and green approaches for utilizing biofibers, and manufacturing methods are discussed in the context of potential application in this review.
Abstract: Composite materials reinforced with biofibers and nanomaterials are becoming considerably popular, especially for their light weight, strength, exceptional stiffness, flexural rigidity, damping property, longevity, corrosion, biodegradability, antibacterial, and fire-resistant properties. Beside the traditional thermoplastic and thermosetting polymers, nanoparticles are also receiving attention in terms of their potential to improve the functionality and mechanical performances of biocomposites. These remarkable characteristics have made nanobiocomposite materials convenient to apply in aerospace, mechanical, construction, automotive, marine, medical, packaging, and furniture industries, through providing environmental sustainability. Nanoparticles (TiO2, carbon nanotube, rGO, ZnO, and SiO2) are easily compatible with other ingredients (matrix polymer and biofibers) and can thus form nanobiocomposites. Nanobiocomposites are exhibiting a higher market volume with the expansion of new technology and green approaches for utilizing biofibers. The performances of nanobiocomposites depend on the manufacturing processes, types of biofibers used, and the matrix polymer (resin). An overview of different natural fibers (vegetable/plants), nanomaterials, biocomposites, nanobiocomposites, and manufacturing methods are discussed in the context of potential application in this review.

131 citations

Journal ArticleDOI
TL;DR: In this paper , the fatigue performance of polypropylene (PP) at various amplitudes and frequencies on fatigue cycles under tensile test conditions is investigated, and the results show that increasing the frequency leads to a decrease in fatigue cycles due to increased cycle time.
Abstract: The fatigue performance of polypropylene (PP) at various amplitudes and frequencies on fatigue cycles under tensile test conditions is investigated in this study. The results show that increasing the frequency leads to a decrease in fatigue cycles due to increased cycle time. The decline rate can be divided into two stages, between 1 and 5 Hz. The first stage rapidly decreases fatigue performance as the frequency increases from 1 Hz to 2 Hz or 3 Hz. The second stage has a lower reduction rate, which occurs between 2 Hz or 3 Hz and 5 Hz due to the strengthening effect of increasing frequency. Furthermore, increasing the amplitude from 0.1 mm to 0.4 mm reduces the fatigue cycle due to the higher deformation rate. In summary, expanding both amplitude and frequency reduces the fatigue performance of the PP material. Moreover, according to the scanning electron microscope microstructure, increasing the frequency results in more microcracks in the polymer matrix.

12 citations

Journal ArticleDOI
TL;DR: In this paper , a review article about natural fiber-reinforced composites, the commonly used fabrication methods, including fiber pre-treatments, and numerous intermediate steps added to achieve improved bonding, processability, and application prospects are discussed.
Abstract: Natural fiber-reinforced polymer composites (NFPCs) have gained limelight in many applications during the recent years, owing to their availability, as well as superior mechanical characteristics, cost-effectiveness, biodegradability, and lightweight. A comprehensive understanding of the manufacturing methods, proeprties and characteristics of natural fibers pave way for begetting a wide spectrum of applications for the NFPCs in automobile, aerospace, electronics, and other engineering fields. The current review article is about natural fiber-reinforced composites, the commonly used fabrication methods, including fiber pre-treatments, and numerous intermediate steps added to achieve improved bonding, processability of these composites, their properties and application prospects. Various state-of-the-art methods like additive manufacturing, vaccum bag molding, and autoclave has also been discussed. The mechanical properties obtained through various fiber reinforcements in accordance with process parameters has a substantial impact in the industrial applications of NFPCs. The tribological applications of NFPCs are becoming increasingly important in order to deal with the mechanical and chemical wear and tear during their service life in contact applications. Flammability behavior and biodegradability assessment of NFPCs are important for high-temperature and outdoor environmental applications of these materials. The review also includes a comprehensive discussion about the trending applications and future prospects for NFPCs.

12 citations

Journal ArticleDOI
TL;DR: In this article, multi wall carbon nanotube (MWCNTs) reinforced polypropylene composites are fabricated by compression molding machine and examined as per ASTM.

8 citations