Professor James Njuguna's Outputs (121)

Tensile properties of epoxy composites filled with graphene nanoplatelets and PUF microcapsules. (2024)
Journal Article
NASCIMENTO, A.P., RIBEIRO, C.G., ZOSCHKE, G.H., NJUGUNA, J. and PEZZIN, S.H. 2024. Tensile properties of epoxy composites filled with graphene nanoplatelets and PUF microcapsules. Macromolecular symposia [online], 413(6): selected papers from the 17th Brazilian polymer conference (17th CBPol), article number 2400102. Available from: https://doi.org/10.1002/masy.202400102

This work evaluates the effect of poly(urea-formaldehyde) (PUF) microcapsules filled with aminated polydimethylsiloxane (PDMS-a), a self-healing agent, on the tensile properties of epoxy composites reinforced with graphene nanoplatelets (GNP). The mi... Read More about Tensile properties of epoxy composites filled with graphene nanoplatelets and PUF microcapsules..

Insights into machining techniques for additively manufactured Ti6Al4V alloy: a comprehensive review. (2024)
Journal Article
SAMBO, A.M., YOUNAS, M. and NJUGUNA, J. 2024. Insights into machining techniques for additively manufactured Ti6Al4V alloy: a comprehensive review. Applied sciences [online], 14(22), article number 10340. Available from: https://doi.org/10.3390/app142210340

Investigation into the post-processing machinability of Ti6Al4V alloy is increasingly crucial in the manufacturing industry, particularly in the machining of additively manufactured (AM) Ti6Al4V alloy to ensure effective machining parameters. This re... Read More about Insights into machining techniques for additively manufactured Ti6Al4V alloy: a comprehensive review..

A review of well life cycle integrity challenges in the oil and gas industry and its implications for sustained casing pressure (SCP). (2024)
Journal Article
IBUKUN, M., ELYAN, E., AMISH, M., NJUGUNA, J. and OLUYEMI, G.F. 2024. A review of well life cycle integrity challenges in the oil and gas industry and its implications for sustained casing pressure (SCP). Energies [online], 17(22), article number 5562. Available from: https://doi.org/10.3390/en17225562

Sustained Casing Pressure (SCP) is a condition in oil and gas wells where continuous pressure buildup in the well casing over a long period of time occurs. Several factors might be responsible for this, including the influx of formation fluids, the l... Read More about A review of well life cycle integrity challenges in the oil and gas industry and its implications for sustained casing pressure (SCP)..

Fabrication with magnetic-spin coating: influence of magnetic-inertia energy ratio on gold-Pickering ferrofluid droplet assembly morphology. (2024)
Journal Article
OKPOZO, P., NJUGUNA, J., ISLAM, S., UYANGA, K. and PANCHOLI, K. 2024. Fabrication with magnetic-spin coating: influence of magnetic-inertia energy ratio on gold-Pickering ferrofluid droplet assembly morphology. Journal of magnetism and magnetic materials [online], 611, article number 172577. Available from: https://doi.org/10.1016/j.jmmm.2024.172577

Magnetic self-assembly of nanoparticles is a well-known technique for creating thin-film array-patterned functional microstructures. However, an uncontrollable hierarchical assembly formation of magnetically stimulated particles has hindered the desi... Read More about Fabrication with magnetic-spin coating: influence of magnetic-inertia energy ratio on gold-Pickering ferrofluid droplet assembly morphology..

Underwater target detection analysis using spherical acoustic sensor arrays. (2024)
Presentation / Conference Contribution
SUNDAS, R., BAIG, N.A., NJUGUNA, J., RAHMAN, K.U. and FOUGH, N. 2024. Underwater target detection analysis using spherical acoustic sensor arrays. In Proceedings of the 2024 IEEE (Institute of Electrical and Electronics Engineers) International workshop on Metrology for the sea; learning to measure sea health parameters (IEEE MetroSea 2024), 14-16 October 2024, Portorose, Slovenia. Piscataway: IEEE [online], pages 240-245. Available from: https://doi.org/10.1109/MetroSea62823.2024.10765723

The need to identify and monitor the target by taking active measurements before it gets close enough to attack has grown due to advancements in marine technology. As underwater vehicular technology continues to progress, there is an increasing inter... Read More about Underwater target detection analysis using spherical acoustic sensor arrays..

The state of the art in hydrogen storage. (2024)
Journal Article
REYNOLDS, J., ALI, D., NJUGUNA, J. and AMADHE, F. 2024. The state of the art in hydrogen storage. Green energy and environmental technology [online], 3(1), pages 1-40. Available from: https://doi.org/10.5772/geet.20240074

The global renewable energy mix is set to change even further with the increasing demand for hydrogen. The production levels are dramatically increasing, and it is becoming prevalent that the storage of hydrogen gas is much more complex than natural... Read More about The state of the art in hydrogen storage..

Effects of cutting conditions on the cutting forces in machining additively manufactured Ti6Al4V alloy. (2024)
Presentation / Conference Contribution
SAMBO, A.M., YOUNAS, M. and NJUGUNA, J. 2024. Effects of cutting conditions on the cutting forces in machining additively manufactured Ti6Al4V alloy. MATEC web of conferences [online], 401: proceedings of the 21st International conference on manufacturing research (ICMR 2024), 28-30 August 2024, Glasgow, UK, article number 06003. Available from: https://doi.org/10.1051/matecconf/202440106003

Machining of additive manufacturing (AM) process results in excessive consumption of the cutting power due to the high strength and hardness of the material produced that led to high cutting forces and short tool life during machining process. This p... Read More about Effects of cutting conditions on the cutting forces in machining additively manufactured Ti6Al4V alloy..

Recent developments in mechanical ultraprecision machining for nano/micro device manufacturing. (2024)
Journal Article
OLANIYAN, T., FAISAL, N. and NJUGUNA, J. 2024. Recent developments in mechanical ultraprecision machining for nano/micro device manufacturing. Micromachines [online], 15(8), article number 1030. Available from: https://doi.org/10.3390/mi15081030

The production of many components used in MEMS or NEMS devices, especially those with com-plex shapes, requires machining as the best option among manufacturing techniques. Ultraprecision machining is normally employed to achieve the required shapes,... Read More about Recent developments in mechanical ultraprecision machining for nano/micro device manufacturing..

Assessment of polymer resins as alternative abandonment barrier materials for high pressure high temperature (HPHT) wells: a multi criteria decision making approach. (2024)
Presentation / Conference Contribution
CHUKWUEMEKA, A., NJUGUNA, J., OLUYEMI, G. and ATTAR, S. 2024. Assessment of polymer resins as alternative abandonment barrier materials for high pressure high temperature (HPHT) wells: a multi criteria decision making approach. In Proceedings of the 2024 Society of Petroleum Engineers (SPE) Nigeria annual international conference and exhibition (NAICE 2024), 5-7 August 2024, Lagos, Nigeria. Hosted on OnePetro [online], paper number SPE-221795-MS. Available from: https://doi.org/10.2118/221795-ms

Portland cement is the predominant material for permanent abandonment of oil and gas wells. However, resins are increasingly finding applications in the mix of barrier materials for plug and abandonment of wells because of unique features that enable... Read More about Assessment of polymer resins as alternative abandonment barrier materials for high pressure high temperature (HPHT) wells: a multi criteria decision making approach..

A study on the factors and mechanisms facilitating renewable energy development and access in Togo. (2024)
Thesis
KANSONGUE, N. 2024. A study on the factors and mechanisms facilitating renewable energy development and access in Togo. Robert Gordon University, PhD thesis. Hosted on OpenAIR [online]. Available from: https://doi.org/10.48526/rgu-wt-2571142

Energy demand is continually increasing due to population growth, improved standard of living, as well as the widespread emergence of industries. This high demand for energy must be met by production with a reasonable reserve margin for sufficiency.... Read More about A study on the factors and mechanisms facilitating renewable energy development and access in Togo..

Developing a hydrogen car demonstration for the actual public: public perceptions/experience. (2024)
Presentation / Conference Contribution
MENYEH, B., OLADIGBO, T., OBUROH, A., FAISAL, N. and NJUGUNA, J. 2024. Developing a hydrogen car demonstration for the actual public: public perceptions/experience. Presented at 2024 Hydrogen accelerator meeting and networking event, 22 March 2024, Edinburgh, UK.

The project titled "Consumer Perceptions Toward Hydrogen Fuel Cell Vehicles: A Demonstrator Project" aims to enhance public awareness and assess consumer responses to hydrogen fuel cell vehicles through a real-world driving experience. The project in... Read More about Developing a hydrogen car demonstration for the actual public: public perceptions/experience..

Quasi-static compression tests of overwrapped composite pressure vessels under low velocity impact. (2023)
Journal Article
MOHAMMED, A.I., RAGHUPATHY, K., BALTAZAR, O.D.V.G., ONOKPASAH, L., CARVALHO, R., MOGENSEN, A., HASSANI, F. and NJUGUNA, J. 2023. Quasi-static compression tests of overwrapped composite pressure vessels under low velocity impact. Composite structures [online], 327, article number 117662. Available from: https://doi.org/10.1016/j.compstruct.2023.117662

Pressure vessels are being utilised in different applications that are indispensable, including automobile, aerospace, underwater vehicles, oil and gas, and chemical engineering among others. However, there is a lack of knowledge on the influence of... Read More about Quasi-static compression tests of overwrapped composite pressure vessels under low velocity impact..

Advances in structural analysis and process monitoring of thermoplastic composite pipes. (2023)
Journal Article
OKOLIE, O., LATTO, J., FAISAL, N., JAMIESON, H., MUKHERJI, A. and NJUGUNA, J. 2023. Advances in structural analysis and process monitoring of thermoplastic composite pipes. Heliyon [online], 9(7), e17918. Available from: https://doi.org/10.1016/j.heliyon.2023.e17918

Thermoplastic composite pipes (TCP) in comparison to other pipes have proven beneficial features due to its flexibility which includes being fit for purpose, lightweight and no corrosion. However, during the manufacturing of TCP which involves the co... Read More about Advances in structural analysis and process monitoring of thermoplastic composite pipes..

Investigation on mechanical and thermal properties of 3D-printed polyamide 6, graphene oxide and glass-fibre-reinforced composites under dry, wet and high temperature conditions. (2023)
Journal Article
ICHAKPA, M., GOODYEAR, M., DUTHIE, J., DUTHIE, M., WISELY, R., MACPHERSON, A., KEYTE, J., PANCHOLI, K. and NJUGUNA, J. 2023. Investigation on mechanical and thermal properties of 3d-printed polyamide 6, graphene oxide and glass-fibre-reinforced composites under dry, wet and high temperature conditions. Journal of composites science [online], 7(6), article 227. Available from: https://doi.org/10.3390/jcs7060227

This study is focused on 3D printing of polyamide 6 (PA6), PA6/graphene oxide (PA6/GO) and PA6/glass-fibre-reinforced (PA6/GF) composites. The effect of graphene oxide and glass-fibre reinforcement on 3D-printed PA6 is explored for improvement of the... Read More about Investigation on mechanical and thermal properties of 3D-printed polyamide 6, graphene oxide and glass-fibre-reinforced composites under dry, wet and high temperature conditions..

Bio-based sustainable polymers and materials: from processing to biodegradation. (2023)
Journal Article
OKOLIE, O., KUMAR, A., EDWARDS, C., LAWTON, L.A., OKE, A., MCDONALD, S., THAKUR, V.K. and NJUGUNA, J. 2023. Bio-based sustainable polymers and materials: from processing to biodegradation. Journal of composites science [online], 7(6), article 213. Available from: https://doi.org/10.3390/jcs7060213

In the life cycle of a material, there will be either chemical or physical change due to varying environmental factors such as biological activity, light, heat, moisture, and chemical conditions. This process leads to polymer property change as perta... Read More about Bio-based sustainable polymers and materials: from processing to biodegradation..

Plug and abandonment of oil and gas wells: a comprehensive review of regulations, practices, and related impact of materials selection. (2023)
Journal Article
CHUKWUEMEKA, A.O., OLUYEMI, G., MOHAMMED, A.I. and NJUGUNA, J. 2023. Plug and abandonment of oil and gas wells: a comprehensive review of regulations, practices, and related impact of materials selection. Geoenergy science and engineering [online], 226, article 211718. Available from: https://doi.org/10.1016/j.geoen.2023.211718

This paper reviews the state of research in permanent barrier materials for plug and abandonment of oil and gas wells to identify key strengths and weaknesses of each barrier material and understand the impact of reservoir conditions and fluids on ba... Read More about Plug and abandonment of oil and gas wells: a comprehensive review of regulations, practices, and related impact of materials selection..

Structural response of a compliant pipe-in-pipe under frictionless and frictional conditions of the seabed. (2023)
Journal Article
MOHAMMED, A.I., BARTZAS, K., JOHNSON, C., SPENCE, S., SYKES, P., KIDD, G., MCCONNACHIE, J. and NJUGUNA, J. 2023. Structural response of a compliant pipe-in-pipe under frictionless and frictional conditions of the seabed. Ocean engineering [online], 276, article 114020. Available from: https://doi.org/10.1016/j.oceaneng.2023.114020

Pipe-in-Pipe (PIP) technology has been studied significantly owing to its superior performance in deep-water and high-pressure high temperature fields than conventional single pipe. The PIP system has excellent track record of mitigating flow assuran... Read More about Structural response of a compliant pipe-in-pipe under frictionless and frictional conditions of the seabed..

A PESTEL and SWOT impact analysis on renewable energy development in Togo. (2023)
Journal Article
KANSONGUE, N., NJUGUNA, J. and VERTIGANS, S. 2023. A PESTEL and SWOT impact analysis on renewable energy development in Togo. Frontiers in sustainability [online], 3, article 990173. Available from: https://doi.org/10.3389/frsus.2022.990173

Like most developing countries, Togo continues to rely on the use of traditional forms of biomass energy which causes tremendous socio-economic, environmental and health hazards. In addition, the imbalanced distribution and use of electricity, petrol... Read More about A PESTEL and SWOT impact analysis on renewable energy development in Togo..

Stress analysis of pipe-in-pipe systems under free span for deep water pipeline applications. (2023)
Journal Article
MOHAMMED, A.I., JOHNSON, C., SPENCE, S., SKYES, P. and NJUGUNA, J. 2023. Stress analysis of pipe-in-pipe systems under free span for deep water pipeline applications. Petroleum and petrochemical engineering journal [online], 7(1). Available from: https://doi.org/10.23880/ppej-16000325

This study examined the phenomena of free span for a pipe -in- pipe (PIP) system for pipeline application. Two different span length of 8 and 30 meters are modelled and simulated using nonlinear stress analysis. The effect of pressure, temperature an... Read More about Stress analysis of pipe-in-pipe systems under free span for deep water pipeline applications..

An evaluation of the morphological, microstructural and mechanical behaviour of the glass fibre/HDPE thermoplastic composite pipe. (2022)
Presentation / Conference Contribution
OKOLIE, O., NJUGUNA, J. and FAISAL, N. 2022. An evaluation of the morphological, microstructural and mechanical behaviour of the glass fibre/HDPE thermoplastic composite pipe. Presented at 2022 Scottish Research Partnership in Engineering 2022, 21 November 2022, Edinburgh, UK.

Composite pipes are increasingly being used as an alternative solution to conventional metal-based pipes. This development is in response to significant corrosion failures with the metallic pipes and enables better decision making especially for the... Read More about An evaluation of the morphological, microstructural and mechanical behaviour of the glass fibre/HDPE thermoplastic composite pipe..