James Njuguna

James Njuguna
Robert Gordon University | RGU · School of Engineering

PhD in Aeronautical Engineering (Composite Structures)

About

174
Publications
131,586
Reads
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7,122
Citations
Citations since 2016
54 Research Items
4779 Citations
20162017201820192020202120220200400600800
20162017201820192020202120220200400600800
20162017201820192020202120220200400600800
20162017201820192020202120220200400600800
Introduction
Professor James Njuguna is the Academic Strategic Lead (Research) at School of Engineering and also leads the Centre for Advanced Engineering Materials at Robert Gordon University. PhD and MSc in Aeronautical Engineering from City, University of London. Former Research Councils United Kingdom (RCUK) Fellow and Marie Curie Fellow. Research focus on composites materials toughness and mechanical properties optimisation to improve impact resistance & thermo-mechanical performance
Additional affiliations
July 2015 - present
Robert Gordon University
Position
  • Director of Research, School of Engineering
August 2013 - December 2018
Robert Gordon University
Position
  • Lecturer
August 2008 - August 2011
Cranfield University
Position
  • Director of Motorsport Engineering

Publications

Publications (174)
Book
Understanding the unique chemical and physical properties of nanostructures has led to many developments in the applications of nanocomposite materials. Their potential in a huge range of areas has also brought concerns about the impact of nanomaterials on the environment and human health. Health and environmental safety of nanomaterials addresses...
Article
In the automotive industry, more and more engineered parts are shifting from metals to engineering plastics. However localised impact loading and long term ageing effects of under-the-hood plastic components is not well understood. In this paper, localised low velocity impact experiments and simulations were conducted on glass fibre-reinforced poly...
Article
Three-phase composites (thermoplastic polymer, glass-fibres and nano-particles) were investigated as an alternative to two-phase (polymer and glass-fibres) composites. The effect of matrix and reinforcement material on the energy absorption capabilities of composite structures was studied in details in this paper. Dynamic and quasi-static axial col...
Article
The results of recent research indicate that the introduction of layered silicate – montmorillonite – into polymer matrix results in increase of thermal stability of a number of polymer nanocomposites. Due to characteristic structure of layers in polymer matrix and nanoscopic dimensions of filler particles, several effects have been observed that c...
Article
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 the production of biogas generated from anaerobic digestion plants, there are a stream of potential...
Article
Full-text available
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 institutions, and private companies. and the results show that raising the renewable energy business share in...
Article
There is a current need for tissue and organ repairs, replacement, and regeneration for patients who suffer from diseased or damaged tissues or organs. This situation is continuously on the rise and the supply of this form of therapy does not meet the patients demand mostly due to lack of donors and biocompatibility issues which causes immune syste...
Preprint
Full-text available
Polymer-metal oxide nanocomposite is a key in developing a high temperature insulation material for power electronics and HVDC and MVDC subsea cables having capability of transmitting offshore renewable energy with lower losses and higher reliability. To achieve higher operation voltage level and larger power capacity at reduced cable size, weight...
Article
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 the production of biogas generated from anaerobic digestion plants, there are a stream of potential...
Article
Polyester fibres reinforced with glass fibres hybridised polyester resin composite (PFR/GFHC) is a unconventional complex high-molecular weight crosslinked network polymer composite, which can be used in the manufacture of structural body parts for lightweight vehicles, armour vest for body protection as well as armours for vehicles. For body armou...
Article
Full-text available
There is a rising demand for replacement, regeneration of tissues and organ repairs for patients who suffer from diseased/damaged bones or tissues such as hip pains. The hip replacement treatment relies on the implant, which may not always meet the requirements due to mechanical and biocompatibility issues which in turn may aggravate the pain. To s...
Article
Full-text available
The ever-increasing demand for environmentally friendly biocomposites for use in various engineering applications requires a strong understanding of these materials properties, especially in automotive applications. This study focused on investigating how the stacking sequence and fibre orientation impacts the damping properties of hybrid flax/carb...
Preprint
Full-text available
This paper presents constructive alignment of intended learning outcomes, teaching and learning activities, and assessments of a course module (Metallic Structures for Motorsport) based on the theory of constructive alignment by John Biggs [1]. The Course module lies within the MSc in Motorsport Engineering and Management. The paper borrows specifi...
Preprint
Full-text available
This article examines the purpose of research-intensive universities where academics takes 'technology transfer' role and are expected to play in economic development in collaborating with governing bodies and industry. Accelerated transfer of knowledge, technology, know-how, and people from university to industry is a subject of great interest to...
Article
Full-text available
Researchers and legislators have both claimed the necessity to standardize the exposure assessment of polymer nanocomposites throughout their life cycle. In the present study we have developed and compared three different and independent operational protocols to investigate changes in particle emission behavior of mechanically degraded polypropylen...
Article
Full-text available
Oil-based mud (OBM) waste from the oil and gas exploration industry can be valorised to tailor-made reclaimed clay-reinforced low-density polyethylene (LDPE) nanocomposites. This study aims to fill the information gap in the literature and to provide opportunities to explore the effective recovery and recycling techniques of the resources present i...
Article
Polymer-metal oxide nanocomposite is a key in developing a high temperature insulation material for power electronics and HVDC and MVDC subsea cables having capability of transmitting offshore renewable energy with lower losses and higher reliability. To achieve higher operation voltage level and larger power capacity at reduced cable size, weight...
Article
Graphene oxide (GO) nanoparticles are increasingly being used to tailor industrial composites. However, despite the advantages, GO has shown conceivable health risks and toxicity to humans and the environment if released. This study investigates the influence that GO concentrations have on nanoparticle emissions from epoxy-reinforced carbon fiber h...
Article
According to a survey conducted by Grand View Research, the market demand for medical grade UHMWPE has raise remarkably from 60.9 kilotons up to 204.8 kilotons during 2015–2024 valued at $1.36 billion (USD) with a compound annual growth rate of 15%. There are various materials available for medical implants comprising of metals, ceramics and polyme...
Article
Full-text available
The application of superabsorbent polymer hydrogels in the oil and gas industry for reservoir and well management is gaining more traction. In this study, the swelling performance and adsorption kinetics of two commercial superabsorbent polymer hydrogels—poly(acrylamide-co-acrylic acid) potassium salt and sodium polyacrylate—were evaluated based up...
Article
Recent research in soft materials is an exhilarating category which has been transcending boundaries for variety of functional applications. This category also stems liquid crystals whose stimuli-responsive feature has fantasized researchers for application arrays in actuators and biomedical. Liquid crystals evince dual characteristics of liquid an...
Article
Full-text available
The two-dimensional macro molecule graphene and its derivatives have widely been investigated for their application as nanofiller in carbon fiber-reinforced composites (CFRC). Research has progressed from techniques that disperse graphene as a mixing constituent within the composite material to more complex examples where graphene is covalently bon...
Data
Supplementary Data for the Publication "Effect of Oleic Acid Coating of Iron Oxide Nanoparticles on Properties of Magnetic Polyamide-6 Nanocomposite" For those who requested it!!
Article
Full-text available
This work reports the development and testing of a magnetic polymer (Polyamide 6, PA6) nanocomposite capable of melting when exposed to an external magnetic field. Addition of high concentrations of iron oxide nanoparticles (NPs) can induce quick melting but is detrimental to the mechanical properties of the polymer. To reduce the amount of NPs req...
Article
Full-text available
In this study, a novel reclaimed clay nanofiller was used to manufacture low-density polyethylene (LDPE)/Oil based mud filler (OBMF) nanocomposites by a melt compounding process. The mechanical testing samples were manufactured using injection moulding. The effect of reclaimed clay minerals influencing the crystallinity and the dispersion character...
Article
Full-text available
This study investigat the effectiveness of reduced graphene oxide as nanofiller in enhancing epoxy/carbon fiber‐reinforced composite at varying temperature conditions. The graphene oxide is synthesized using modified Hummer's method and then is chemically reduced to yield reduced graphene oxide (rGO). The rGO is dispersed in epoxy matrix system thr...
Article
The crystallinity and thermal degradation behaviours of Polyamide 6/Oil Based Mud Fillers (PA6/OBMFs) nanocomposites have been investigated using differential scanning and thermogravimetry (TGA). The TGA indicates the onset decomposition temperature of D1/2 (half-decomposition) is 16 °C higher for PA6 with 10.0 wt% of OBMFs than that of PA6, wherea...
Article
Full-text available
This work focuses on the proof-mass mechanical structural design improvement of a tri-axial piezoresistive accelerometer specifically designed for head injuries monitoring where medium-G impacts are common; for example, in sports such as racing cars or American Football. The device requires the highest sensitivity achievable with a single proof-mas...
Preprint
This work focuses on the design improvement of a tri-axial piezoresistive accelerometer specifically designed for head injuries monitoring where medium-G impacts are common, for example in sports such as racing cars or American Football. The device requires the highest sensitivity achievable with a single proof mass approach, and a very low error (...
Article
Full-text available
This work focuses on the design improvement of a tri-axial piezoresistive accelerometer [...]
Article
Lead (Pb) pollution is our water system is a major concern, as this metal is toxic even at low concentration. This study aim to fabricate a bio-nanocomposite (cyclodextrin-polycaprolactone titanium dioxide) that will be used as an adsorbent for the removal of lead in aqueous waste. In this study, titanium dioxide was synthesized via sol-gel techniq...
Conference Paper
This work focuses on the design improvement of a tri-axial piezoresistive accelerometer specifically designed for head injuries monitoring where medium-G impacts are common, for example in sports such as racing cars. The device requires the highest sensitivity achievable with a single proof mass approach, and a very low error as the accuracy for th...
Conference Paper
Full-text available
The possibility of combining the flexibility and lightweight of polymers with the highest insulation of ceramics, drives the field of nanocomposites for potential commercial application. The inclusion of nano-sized insulating particles in the polymer matrix, and orienting the fillers along the direction of heat flow results in modifying the induced...
Article
Full-text available
In this research work, we report circular type silane-modified CaCO3 (as core) nanoparticles (NP) encapsulated with polystyrene (PS) and polymethyl methacrylate (PMMA) (as double shell layers). These core–double shell [CaCO3–PS/PMMA] hybrid nanostructures were prepared by a stepwise micro-emulsion polymerization and characterized by fourier transfo...
Article
The risk assessment, exposure and understanding of the release of embedded carbon nanotubes (CNTs) and carbon nanofibers (CNFs) from commercial high performance composites during machining processes is yet to be fully evaluated and quantified. In this study, CNTs and CNFs were dispersed in epoxy matrix through calendaring process to form nanocompos...
Article
Full-text available
The aim of this study is to investigate the effect nanosilica and nanoalumina has on nanoparticle release from industrial nanocomposites due to drilling for hazard reduction whilst simultaneously obtaining the necessary mechanical performance. This study is therefore specifically designed such that all background noise is eliminated in the measurem...
Article
Full-text available
Operational discharges of spent drilling fluid, produced water, and accumulated drill cuttings from oil and gas industry are a continuous point source of environmental pollution. To meet the strict environmental standard for waste disposal, oil and gas industry is facing a numerous challenges in technological development to ensure a clean and safe...
Article
Full-text available
In this study, the effect on nanoparticle emissions due to drilling on Polypropylene (PP) reinforced with 20% talc, 5% montmorillonite (MMT) and 5% Wollastonite (WO) is investigated. The study is the first to explore the nanoparticle release from WO and talc reinforced composites and compares the results to previously researched MMT. With 5% WO, eq...
Article
Full-text available
The Robert Gordon University, Aberdeen hosted The NANOSTRUC 2016 in Aberdeen (Scotland, United Kingdom). The conference focused on 'Nanoscience and Nanotechnologies – Recent Advances towards Nanoproducts and Applications'. It promoted activities in various areas on materials and structures by providing a forum for exchange of ideas, presentation of...
Article
Full-text available
In this study, nano-sized graphene oxide sheets were homogenously dispersed via sonication methods in epoxy followed by vacuum resin infusion for the fabrication of the epoxy, graphene oxide (GO) and micro-sized carbon fibre reinforced nanocomposites (EP/CF/GO). Graphene oxide concentrations ranging from 0.1 – 0.5 wt. % were studied to investigate...
Article
Full-text available
In this research work, properties of graphene oxide (GO) based epoxy nanocomposites, prepared via the solution blending method, are elaborated. Different loadings (0.1–0.5 wt%) of GO were added into epoxy resin, and their effects were studied on their surface reaction, morphology, mechanical and thermal properties. It was found that a chemical modi...
Article
Full-text available
Exfoliated graphene oxide (GO) and Mg-Al-layered double hydroxides (LDHs) nanostructures ([email protected]/* */)-filled ethylene vinyl acetate (EVA)-based hybrid nanocomposites were prepared by solution reflux technique followed by injection molding. The physico-mechanical (including morphological, thermal, and mechanical) properties of [email pro...
Article
Full-text available
In this work, nano polystyrene (nPS) decorated graphene oxide (GO) hybrid nanostructures were successfully synthesized using stepwise micro emulsion polymerization, and characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffractometer (XRD), field-emission scanning electron microscopy (FE-SEM) and transmission electron microscop...
Chapter
The properties of thermoplastics are temperature dependent owing to the fact that they are soft when heated and hard when cooled. An increase in temperature reduces the Young's modulus and tensile strength but increases the failure strain, leading to a material more ductile and less stiff. Of particular concern are under-the-hood thermoplastic part...
Chapter
This chapter introduces the product end-of-life (EoL) scenarios for automotive components, with particular interest in remanufacture. Whole-life cost is discussed in relation to the product EoL of automotive components. Cost–benefit analyses for assessing the EoL options are introduced, and some potentially better EoL options for specified situatio...
Chapter
The use of lightweight materials has become more prevalent as transport vehicle manufacturers strive to reduce vehicle weight to improve performance, to lower fuel and oil consumption, and to reduce emissions. Mass reduction, manufacturing process, and recycling are paramount in the transport sector in achieving CO2 (and pollutant gasses) emission...
Article
This paper presents a study of stress states in two-dimensional models of metal-to-metal adhesively bonded joints subjected to 4-point flexural loading using finite element (FE) method. The FE simulations were carried out on adhesive bonded joints of high support span to specimen thickness ratio undergoing extensive plastic deformations. Two differ...
Book
The first book to extensively cover nanoparticles, this addresses some of the key issues in nanocomposites. Polymer nanocomposites (polymers reinforced with nanoparticles), are of great interest due to their remarkable mechanical, thermal, chemical properties as well as optical, electronic, and magnetic applications Potential applications include a...
Article
The paraffin oil dispersion technique innovated in the recent years to synthesize bulk polymer nanocomposite materials has a uniform dispersion. This research work aims to study the effect of added carbon nanotubes (CNTs) on flexural, impact and rheology behaviors of polyoxymethylene (POM) reinforced by 0–0.03 wt% of CNT using paraffin oil dispersi...
Article
Ultra-high molecular weight polyethylene (UHMWPE) is a very attractive polymer employed as a high performance material. For its high viscosity, dispersion of fillers is considered a critical point in UHMWPE nanocomposites preparation process. Currently, paraffin oil (PO) is used extensively to overcome this issue in an assisted melt-mixing process....
Book
Lightweight Composite Structures in Transport: Design, Manufacturing, Analysis and Performance provides a detailed review of lightweight composite materials and structures and discusses their use in the transport industry, specifically surface and air transport. The book covers materials selection, the properties and performance of materials, and s...
Chapter
The incorporation of fillers and the modification of polymer–filler interfaces changed the crystalline structure of the matrix in some way, which promoted the matrix polymer to undergo shear yielding and prevented the crazes from developing into catastrophic cracks. These effects, combined with the favorable stress conditions, resulted in a dramati...
Article
Full-text available
The present special topic ‘‘Futuristic Nanomaterials and Composites: Part II’’ is a continuation of last month’s topic ‘‘Futuristic Nanomaterials and Composites: Part I’’. In this continuation, inspira- tion is once again drawn from two conferences: (1) NANOSTRUC 2014: International Conference on Structural Nano Composites held in Madrid (Spain) on...
Article
The wear of polyoxymethylene (POM) is considered as a key design parameter of polymer gears and some mechanical applications and determines the service time span. This work investigates the influence of carbon nanotubes (CNT) on the specific wear rate of POM/CNT nanocomposites using a pin on disk test rig (sliding only). The CNT were synthesised us...
Article
Full-text available
The wear of polyoxymethylene (POM) is considered as a key design parameter of polymer gears and some mechanical applications and determines the service time span. This work investigates the influence of carbon nanotubes (CNT) on the specific wear rate of POM/CNT nanocomposites using a pin on disk test rig (sliding only). The CNT were synthesised us...
Preprint
Full-text available
This article examines the purpose of research-intensive universities where academics takes 'technology transfer' role and are expected to play in economic development in collaborating with governing bodies and industry. Accelerated transfer of knowledge, technology, know-how, and people from university to industry is a subject of great interest to...
Article
The present special topic ‘‘Futuristic Nanomaterials and Composites: Part I’’ captures the structural as well as functional aspects of nanomaterials and nanocomposites that are unique in some specific way when compared to their microscale counterparts. The uniqueness of structural qualities covered includes enhanced fracture toughness and wear resi...
Conference Paper
To overcome the limitations of conventional electronic sensors currently used for downhole monitoring of oil and gas wells, including drastic reduction in reliability, long term instability and susceptibility to electromagnetic interference, a multiplexed fibre Bragg grating (FBG)/extrinsic Fabry-Perot interferometer (EFPI) sensor for simultaneous...
Article
In this study, the thermo-mechanical performance of flax fibre reinforced poly lactic acid (PLA) biocomposites was investigated for the potential use in load bearing application such as body-in-white and body structures in the automotive sector. Focus was given into the relationships between the thermal and mechanical properties, and the material r...
Article
An important goal in stem cell research is to control differentiation and direct it to the desired cell lineage. Here we demonstrate the effect of nanotopography of substrates. A number of parameters are important to guide stem cell behaviour. These parameters include geometry, size, lateral spacing and surface chemistry and have been reported to a...
Chapter
Humans have utilized clay minerals since prehistoric times. With advances in nanotechnology and the increased need for sustainable development, naturally occurring clay minerals and their man-made variants provide hope for further improving the quality of human life. However, high levels or inappropriate exposure of clay minerals to the environment...
Preprint
Full-text available
Teachers identify a personal philosophy of teaching and continuously examine, testify, and verify this philosophy, recognizing that through teaching one can lead to change of teaching behaviours and ultimately foster professional and personal growth. In this paper, the author presents his teaching philosophy, goals, strategies, and discusses his te...
Article
Full-text available
Over the past decade, polymer nanocomposites have undergone intensive research and development ensued by its increasing implementation within commercial applications. Consequently, the full life-cycle performance and any health risks associated with these materials have become of major interest. Throughout its use, a nanocomposite will undergo indu...
Article
Full-text available
Due to the European Union (EU) waste frame work directive (WFD), legislations have been endorsed in EU member states such as UK for the Recycling of wastes with a vision to prevent and reduce landfilling of waste. Spent oil based drilling mud (drilling fluid) is a waste from the Oil and Gas industry with great potentials for recycling after appropr...
Article
Full-text available
One of the problems in the design of automotive structures and body parts made by fibre reinforced composites is that these materials are susceptible to a small energy impact caused by for instance, accidental tool drop during maintenance or stone strike while in operation. This often lead to a barely visible impact damage which causes reduction in...
Article
Full-text available
Nanophased hybrid composites based on polyurethane/montmorillonite (PU/MMT) have been fabricated. The nanocomposite which was formed by the addition of a polyol premix with 4,4'-diphenylmethane diisocyanate to obtain nanophased polyurethane foams which were then used for fabrication of nanocomposite panels has been shown to have raised strength, st...
Article
Full-text available
The NANOSTRUC 2014 took place at CSIC, Madrid, Spain. The conference theme on 'Nanosciences and Nanotechnologies – Recent Advances towards Nanoproducts and Applications'. The conference aimed to promote activities in various areas of materials and structures by providing a forum for exchange of ideas, presentation of technical achievements and disc...