Professor James Njuguna's Outputs (82)

Thermo-physical behaviour of thermoplastic composite pipe for oil and gas applications. (2025)
Journal Article
OKOLIE, O., FAISAL, N.H., JAMIESON, H., MUKHERJI, A. and NJUGUNA, J. 2025. Thermo-physical behaviour of thermoplastic composite pipe for oil and gas applications. Polymers [online], 17(8), article number 1107. Available from: https://doi.org/10.3390/polym17081107

Thermoplastic composite pipes (TCP) consist of three distinct layers—liner, reinforcement, and coating—offering superior advantages over traditional industrial pipes, including flexibility, lightweight construction, and corrosion resistance. This stu... Read More about Thermo-physical behaviour of thermoplastic composite pipe for oil and gas applications..

Blue hydrogen in the United Kingdom: a policy and environmental case study. (2025)
Journal Article
OBUROH, A., OKE, A., NJUGUNA, J. and YOUNAS, M. 2025. Blue hydrogen in the United Kingdom: a policy and environmental case study. Energy reviews [online], 4(2), article number 100131. Available from: https://doi.org/10.1016/j.enrev.2025.100131

Blue hydrogen is one of the energy carriers to be adopted by the United Kingdom to reduce emissions to net Zero by 2050 and its use is majorly influenced by policy and technological innovations. With more than 10 blue hydrogen facilities planning pro... Read More about Blue hydrogen in the United Kingdom: a policy and environmental case study..

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..

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..

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..

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..

Manufacturing defects in thermoplastic composite pipes and their effect on the in-situ performance of thermoplastic composite pipes in oil and gas applications. (2022)
Journal Article
OKOLIE, O., LATTO, J., FAISAL, N., JAMIESON, H., MUKHERJI, A. and NJUGUNA, J. 2023. Manufacturing defects in thermoplastic composite pipes and their effect on the in-situ performance of thermoplastic composite pipes in oil and gas applications. Applied composite materials [online], 30(1), pages 231-306. Available from: https://doi.org/10.1007/s10443-022-10066-9

Thermoplastic composite pipes (TCP), which are a form of fibre reinforced thermoplastic pipes, have proven benefits such as being lightweight and non-corrosive. However, during manufacturing, certain defects are induced because of certain parameters,... Read More about Manufacturing defects in thermoplastic composite pipes and their effect on the in-situ performance of thermoplastic composite pipes in oil and gas applications..

An assessment on effect of process parameters on pull force during pultrusion. (2022)
Journal Article
MUKHERJI, A. and NJUGUNA, J. 2022. An assessment on effect of process parameters on pull force during pultrusion. International journal of advanced manufacturing technology [online], 121(5-6), pages 3419-3439. Available from: https://doi.org/10.1007/s00170-022-09221-0

This research investigates the process behaviour by prediction of the pull force required to drag the raw materials through heated die at different reinforcing material configuration during pultrusion. Pultrusion is a continuous manufacturing process... Read More about An assessment on effect of process parameters on pull force during pultrusion..

Multi-criteria material selection for casing pipe in shale gas wells application. (2022)
Journal Article
MOHAMMED, A.I., BARTLETT, M., OYENEYIN, B., KAYVANTASH, K. and NJUGUNA, J. 2022. Multi-criteria material selection for casing pipe in shale gas wells application. Journal of petroleum exploration and production technology [online], 12(12), pages 3183-3199. Available from: https://doi.org/10.1007/s13202-022-01506-0

The conventional method of casing selection is based on availability and/or order placement to manufacturers based on certain design specifications to meet the anticipated downhole conditions. This traditional approach is very much dependent on exper... Read More about Multi-criteria material selection for casing pipe in shale gas wells application..

An evaluation of feedstocks for sustainable energy and circular economy practices in a small island community. (2022)
Journal Article
REYNOLDS, J., KENNEDY, R., ICHAPKA, M., AGARWAL, A., OKE, A., COX, E., EDWARDS, C. and NJUGUNA, J. 2022. An evaluation of feedstocks for sustainable energy and circular economy practices in a small island community. Renewable and sustainable energy reviews [online], 161, article 112360. Available from: https://doi.org/10.1016/j.rser.2022.112360

Maximising the use of anaerobic digestion to generate power from waste feedstocks is becoming a practical way to use waste contributing to the transition from a linear to a circular economy and reducing the carbon footprint. In addition to harnessing... Read More about An evaluation of feedstocks for sustainable energy and circular economy practices in a small island community..