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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..

The state of the art in hydrogen storage. (2023)
Journal Article
REYNOLDS, J., ALI, D. and NJUGUNA, J. 2023. The state of the art in hydrogen storage. Green energy and environmental technology [online], (accepted).

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..

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..

Oil-based mud waste as a filler material in LDPE composites: evaluation of mechanical properties. (2022)
Journal Article
SIDDIQUE, S., NOVAK, A., GULIYEV, E., YATES, K., LEUNG, P.S. and NJUGUNA, J. 2022. Oil-based mud waste as a filler material in LDPE composites: evaluation of mechanical properties. Polymers [online], 14(7), article 1455. Available from: https://doi.org/10.3390/polym14071455

Traditionally, the drilling waste generated in oil and gas exploration operations, including spent drilling fluid, is disposed of or treated by several methods, including burial pits, landfill sites and various thermal treatments. This study investig... Read More about Oil-based mud waste as a filler material in LDPE composites: evaluation of mechanical properties..

Thermal spray coatings for electromagnetic wave absorption and interference shielding: a review and future challenges. (2022)
Journal Article
FASIAL, N.H., AHMED, R., SELLAMI, N. et al. 2022. Thermal spray coatings for electromagnetic wave absorption and interference shielding: a review and future challenges. Advanced engineering materials [online], 24(7), article number 2200171. Available from: https://doi.org/10.1002/adem.202200171

This review aims to consolidate scattered literature on thermally sprayed coatings with nonionizing electromagnetic (EM) wave absorption and shielding over specific wavelengths potentially useful in diverse applications (e.g., microwave to millimeter... Read More about Thermal spray coatings for electromagnetic wave absorption and interference shielding: a review and future challenges..

Effect of fillers on compression loading performance of modified re-entrant honeycomb auxetic sandwich structures. (2022)
Journal Article
FAISAL, N.H., SCOTT, L., BOOTH, F., DUNCAN, S., MCLEOD, A., DROUBI, M.G. and NJUGUNA, J. 2023. Effect of fillers on compression loading performance of modified re-entrant honeycomb auxetic sandwich structures. Journal of strain analysis for engineering design [online], 58(2), pages 98-117. Available from: https://doi.org/10.1177/03093247221083210

The auxetic sandwich panels for structures have been designed to provide impact protection. The aim of this work is to modify an auxetic (re-entrant) honeycomb cell to reduce the stress concentrations within the cell structure, and further enhancemen... Read More about Effect of fillers on compression loading performance of modified re-entrant honeycomb auxetic sandwich structures..

Optimising crystallisation during rapid prototyping of Fe3O4-PA6 polymer nanocomposite component. (2022)
Journal Article
GUPTA, R., NJUGUNA, J. and PANCHOLI, K. 2022. Optimising crystallisation during rapid prototyping of Fe3O4-PA6 polymer nanocomposite component. Journal of composites science [online], 6(3), article 83. Available from: https://doi.org/10.3390/jcs6030083

Polymer components capable of self-healing can rapidly be manufactured by injecting the monomer (ε-caprolactam), activator and catalyst mixed with a small amount of magnetic nanoparticles into a steel mould. The anionic polymerisation of the monomer... Read More about Optimising crystallisation during rapid prototyping of Fe3O4-PA6 polymer nanocomposite component..

Material challenges and opportunities in 3D printing for hip implant applications. (2022)
Journal Article
OKOLIE, O., STACHUREK, I., KANDASUBRAMANIAN, B. and NJUGUNA, J. 2022. Material challenges and opportunities in 3D printing for hip implant applications. Recent progress in materials [online], 4(1): 3D printing of engineering materials, article 2201004. Available from: https://doi.org/10.21926/rpm.2201004

There is a current need for tissue and organ repairs, replacement and regeneration for the patients who suffer from diseased/damaged tissues or organs. This situation is continuously on the rise and the supply on this form of therapy does not meet th... Read More about Material challenges and opportunities in 3D printing for hip implant applications..

An assessment of renewable energy development in energy mix for Togo. (2022)
Journal Article
KANSONGUE, N., NJUGUNA, J. and VERTIGANS, S. 2022. An assessment of renewable energy development in energy mix for Togo. International journal of sustainable energy [online], 41(8), pages 1037-1056. Available from: https://doi.org/10.1080/14786451.2021.2023150

The Togolese government plans to achieve 100% electrification to all by 2030, to meet the Millennium goals. The Delphi method is used with the experts drawn from policymakers, academic institutions, financial institutions, non-governmental institutio... Read More about An assessment of renewable energy development in energy mix for Togo..

The fate of waste drilling fluids from oil and gas industry activities in the exploration and production operations. (2022)
Journal Article
NJUGUNA, J., SIDDIQUE, S., KWROFFIE, L.B., PIROMRAT, S., ADDAE-AFOAKWA, K., EKEH-ADEGBOTOLU, U., OLUYEMI, G., YATES, K., MISHRA, A.K. and MOLLER, L. 2022. The fate of waste drilling fluids from oil and gas industry activities in the exploration and production. Waste management [online], 139, pages 362-380. Available from: https://doi.org/10.1016/j.wasman.2021.12.025

Operational discharges from oil and gas exploration industry, accidental spillage, or improperly disposed drilling wastes has serious detrimental effects on human and the environment. The water- and oil-based fluids wastes are generated every year al... Read More about The fate of waste drilling fluids from oil and gas industry activities in the exploration and production operations..