Professor James Njuguna's Outputs (121)

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..

A holistic power systems asset engineering and decision management framework for railway asset managers. (2022)
Preprint / Working Paper
BRUINERS, J., NJUGUNA, J. and AGARWAL, A. 2022. A holistic power systems asset engineering and decision management framework for railway asset managers. Hosted on OpenAIR [online]. Available from: https://rgu-repository.worktribe.com/output/1777336

Defining, designing and implementing an asset management system capable of effectively managing assets throughout their life in terms of engineering, financial, digital and stakeholder needs is challenging. Furthermore, governance frameworks of the p... Read More about A holistic power systems asset engineering and decision management framework for railway asset managers..

Case study: multi-billion pound infrastructure decision making: a regulatory infrastructure asset management assessment. (2022)
Report
BRUINERS, J., NJUGUNA, J. and AGARWAL, A. 2022. Case study: multi-billion pound infrastructure decision making: a regulatory infrastructure asset management assessment. Hosted on OpenAIR [online]. Available from: https://rgu-repository.worktribe.com/output/1777830

This paper evaluates the effectiveness of a hypothesised asset management decision framework implemented with a High-Speed Railway Infrastructure Asset in the U.K over a three-year period. The physical infrastructure asset(s) consists of a complex as... Read More about Case study: multi-billion pound infrastructure decision making: a regulatory infrastructure asset management assessment..

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. [Dataset] (2022)
Data
GUPTA, R., NJUGUNA, J. and PANCHOLI, K. 2022. Optimising crystallisation during rapid prototyping of Fe3O4-PA6 polymer nanocomposite component. [Dataset]. Journal of composites science [online], 6(3), article 83. Available from: https://www.mdpi.com/2504-477X/6/3/83/s1

This paper discusses the effect of the catalyst and the activator concentrations on the properties of polymerised PA6-PMC containing 1 wt% uncoated MNPs. The focus herein is to tune the degree of crystallinity of the prepared PA6-PMC for the optimum... Read More about Optimising crystallisation during rapid prototyping of Fe3O4-PA6 polymer nanocomposite component. [Dataset].

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..

Design and analysis of non-threaded drill pipe connector. (2022)
Thesis
THAKUR, J.O. 2022. Design and analysis of non-threaded drill pipe connector. Robert Gordon University, MRes thesis. Hosted on OpenAIR [online]. Available from: https://doi.org/10.48526/rgu-wt-2271554

This thesis determines the feasibility and application opportunities of a Snap-Latch Ring design based on the Pin and Box non-threaded connectors design. Modern drill pipes are connected by rotary threaded shouldered connections that have been prone... Read More about Design and analysis of non-threaded drill pipe connector..

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..

Determination of cure mechanism inside die for a part manufacturing during large-scale pultrusion. (2021)
Journal Article
MUKHERJI, A., TARAPORE, N. and NJUGUNA, J. 2022. Determination of cure mechanism inside die for a part manufacturing during large-scale pultrusion. Journal of applied polymer science [online], 139(17), article 52035. Available from: https://doi.org/10.1002/app.52035

The cure kinetics of resin, heat capacity and thermal conductivity of reinforcing materials of uncured mass dictates the ultimate curing of reinforced thermosets manufactured component. In this study, degree of conversion from heat capacity by ‘Lumry... Read More about Determination of cure mechanism inside die for a part manufacturing during large-scale pultrusion..

Magnetic polyamide 6 nanocomposites for increasing damage tolerance through self-healing of composite structures. (2021)
Thesis
GUPTA, R. 2021. Magnetic polyamide 6 nanocomposites for increasing damage tolerance through self-healing of composite structures. Robert Gordon University, PhD thesis. Hosted on OpenAIR [online]. Available from: https://doi.org/10.48526/rgu-wt-1987943

Self-healing materials have the ability to repeatedly repair damages that occur before complete failure of materials. The development of stimuli-responsive self-healing materials has been in demand recently for composite structures, since their failu... Read More about Magnetic polyamide 6 nanocomposites for increasing damage tolerance through self-healing of composite structures..

An investigation of casing structural integrity in shale gas horizontal wells during hydraulic fracturing using FEA and machine learning algorithms. (2021)
Thesis
MOHAMMED, A.I. 2021. An investigation of casing structural integrity in shale gas horizontal wells during hydraulic fracturing using FEA and machine learning algorithms. Robert Gordon University, PhD thesis. Hosted on OpenAIR [online]. Available from: https://doi.org/10.48526/rgu-wt-1603216

Unconventional oil and gas operators are currently facing the challenge of casing lateral buckling and/or deformation during shale gas wells stimulation through hydraulic fracturing. Failure of the casing during this process can lead to huge financia... Read More about An investigation of casing structural integrity in shale gas horizontal wells during hydraulic fracturing using FEA and machine learning algorithms..

An application of FEA and machine learning for the prediction and optimisation of casing buckling and deformation responses in shale gas wells in an in-situ operation. (2021)
Journal Article
MOHAMMED, A.I., BARTLETT, M., OYENEYIN, B., KAYVANTASH, K. and NJUGUNA, J. 2021. An application of FEA and machine learning for the prediction and optimisation of casing buckling and deformation responses in shale gas wells in an in-situ operation. Journal of natural gas science and engineering [online], 95, article 104221. Available from: https://doi.org/10.1016/j.jngse.2021.104221

This paper proposes a novel way to study the casing structural integrity using two approaches of finite element analysis (FEA) and machine learning. The approach in this study is unique, as it captures the pertinent parameters influencing the casing... Read More about An application of FEA and machine learning for the prediction and optimisation of casing buckling and deformation responses in shale gas wells in an in-situ operation..

Correction to: Swelling performance of sodium polyacrylate and poly(acrylamide‑co‑acrylic acid) potassium salt. (2021)
Journal Article
MAHON, R., BALOGUN, Y., OLUYEMI, G., and NJUGUNA, J. 2021. Correction to: Swelling performance of sodium polyacrylate and poly(acrylamide-co-acrylic acid) potassium salt. SN applied sciences [online], 3(8), article 756. Available from: https://doi.org/10.1007/s42452-021-04654-w

The original version of this Article contained an error of judgement in the inclusion of the names of the polymers and their application. The names of the polymers and their application were included, however, due to potential issues relating to conf... Read More about Correction to: Swelling performance of sodium polyacrylate and poly(acrylamide‑co‑acrylic acid) potassium salt..