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A prosthesis is loaded by forces and torques exerted by its wearer, the amputee, and should withstand instances of peak loads without failure. Traditionally, strong prosthetic sockets were made using a composite with a variety of reinforcing fibres, such as glass, carbon, and Kevlar. Amputees in less-resourced nations can lack access to composite prosthetic sockets due to their unavailability or prohibitive cost. Therefore, this study investigates the feasibility of polyethylene terephthalate (PET) fibre-reinforced composites as a low-cost sustainable composite for producing functional lower-limb prosthetic sockets. Two types of these composites were manufactured using woven and knitted fabric with a vacuum-assisted resin transfer moulding (VARTM) process. For direct comparison purposes, traditional prosthetic-socket materials were also manufactured from laminated composite (glass-fibre-reinforced (GFRP)), monolithic thermoplastic (polypropylene (PP) and high-density polyethylene (HDPE)) were also manufactured. Dog-bone-shaped specimens were cut from flat laminates and monolithic thermoplastic to evaluate their mechanical properties following ASTM standards. The mechanical properties of PET-woven and PET-knitted composites were found to have demonstrated to be considerably superior to those of traditional socket materials, such as PP and HDPE. All the materials were also tested in the socket form using a bespoke test rig reproducing forefoot loading according to the ISO standard 10328. The static structural test of sockets revealed that all met the target load-bearing capacity of 125 kg. Like GFRP, the PETW and PETK sockets demonstrated higher deformation and stiffness resistance than their monolithic counterparts made from PP and HDPE. As a result, it was concluded that the PET-based composite could replace monolithic socket materials in producing durable and affordable prostheses.

Significant heat-transfer enhancement using steam-ethanol mixtures can be obtained as compared to that of pure steam. Due to addition of small concentrations of ethanol, the condensate mode resembles that of typical dropwise condensation on a hydrophobic surface. Surface tension instabilities, also known as Marangoni phenomenon, take place when small amounts of ethanol are added to pure steam. It has been investigated extensively for the case of single tubes. However, it is difficult to extrapolate single-tube data to banks of tubes due to the complex nature of three-dimensional flows and interactions between vapor and liquid. In this paper, data are presented for condensation of pure steam as well as for steam-ethanol mixtures on a horizontal bank of tubes at atmospheric pressure. Present pure steam data are validated by comparing with earlier data and theoretical models available in literature. Condensation of steam-ethanol mixture was investigated using five concentrations of ethanol by mass in the boiler when cold prior to startup, i.e., 0.025, 0.05, 0.1, 0.5, and 1% at vapor velocity of 3.2 and 3.7 m/s. On the top rows maximum heat-transfer enhancement of around 4 and 2.5 times was obtained using ethanol mass fraction of 0.05 and 1.0%, respectively.

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. A continuous increase in energy prices and the growing concern about global warming has created an urge to increase the energy efficiency of residential buildings. In this paper, the reduction of heat loss by incorporating porosity in a monolithic material was studied. To this aim, various sizes of the polymer-based lattice panels were developed using a triangular unit cell. A new technique based on moulding was used to develop commercial size (1 m2) panels which were not possible with normal 3D printers. A novel, experimental results-based, scaling law was used to predict the thermal performances of these polymer lattice-based panels. Besides, the thermal performance of these lattice-based panels was also investigated using an in-house built calorimeter box and a commercial guard hot box chamber by exposing them to a temperature difference of around 30°C. It was observed that the scaling up of the unit cell size to manufacture commercial-size panels did not affect its U-value; even though the heat transfer through the lattice cell is heavily dependent on the unit cell size. It was also observed that the hydraulic diameter of the polymer-lattice structures of value less than 8mm leads only to a conductive mode of heat transfer. The effect of testing parameters such as sensor location and the temperature gradient across lattice on the U-value of the polymer lattice was also characterised and made recommendations for achieving the higher thermal resistance of the lattice panels to make them suitable for the energy-saving in building applications.

Nanofluids have emerged as potential prospect coolant in heat transfer applications. Hybrid nanofluid is the is the recently developed class of nanofluids having two different types of nanoparticles suspended in the base fluid. In this research, a novel hybrid nanofluid containing Fe2O3-TiO2 (50:50) nanoparticles suspended in water basefluid has been used to improve the convective heat transfer in aluminum tube automotive radiator. Three hybrid nanoparticle concentrations (0.005 vol.%, 0.007 vol.% and 0.009 vol.%) were tested. Effect of inlet temperature and fluid velocity on heat transfer rate was examined by varying the inlet temperature from 48 °C to 56 °C and flowrate from 11 LPM to 15 LPM. Heat transfer rate increased by a maximum of 26.7% at 56 °C inlet temperature, 15 LPM flowrate and 0.009 vol.% nanoparticle concentration. At aforementioned operating conditions, Nusselt number increased by 20.03%. Increase in inlet temperature from 48 °C to 56 °C increased the heat transfer rate by 8%. Past 0.009 vol.% concentration, nanoparticle clogging diminished the stability of hybrid nanofluid which results in overall performance deterioration.

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. Digital manufacturing was employed to 3D print continuous Carbon, Glass and Kevlar fibre reinforced composites in Unidirectional (UD) [0°], Off-axis ±45° and Cross-ply [0°/90°] layup sequence. These 3D printed composites were subjected to quasi-static, in-plane tension and out-of-plane (compression and shear) loading. The tensile strength of 3D printed Carbon, Glass and Kevlar UD laminates was significantly lower than that of 3D printing filaments used to manufacture them. The type of fibre (brittle/ductile) reinforcement was found to be governing the shear yield strength of 3D printed composites despite having the same Nylon matrix in all the composites. Out-of-plane compressive strength of the 3D printed Carbon and Glass fibre reinforced composites was independent of specimen size. Contrary to that, Kevlar fibre composites showed a pronounced size effect upon their out-of-plane compressive strength. A combination of X-ray tomography and pressure film measurements revealed that the fibres in 3D printed composites failed by ‘indirect tension’ mechanism which governed their out-of-plane compressive strength. To gain further insights on the experimental observations, Finite Element (FE) simulations were carried out using a pressure-dependent crystal plasticity framework, in conjunction with an analytical model based on shear-lag approach. Both FE and analytical model accurately predicted the out-of-plane compressive strength of all (Carbon, Glass and Kevlar fibre reinforced) 3D printed composites.

Prosthetic Sockets serve as an integral link between the amputee’s residual limb and the rest of the prosthesis. Focusing on sustainability (recycling and bio-degradable), we explore the suitability of self-reinforced(sr) PLA and PET composite as alternative materials for manufacturing prosthetic sockets. For this purpose, we performed tensile and flexural testing on commingled woven srPLA and srPET composite. The srPLA exhibits elastic-brittle response having an average failure strain of 2%. In contrast, srPET displays elastic-plastic response with average failure strain reaching up to 20%. The tensile and flexural strength of srPET is 132MPa and 72MPa, respectively. This is on par with the standard prosthetic socket materials including Glass and Carbon fibre reinforced composite with thermoset matrix. Therefore, srPET could be the realistic alternative for manufacturing sustainable prosthetic sockets. In contrast, the srPLA has inferior mechanical properties to that of standard prosthetic socket materials. Since the srPLA composite has recyclability and bio-degradability, it can be used to manufacture the test or check sockets; thus reducing the plastic pollution due to discarded check sockets.

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. New cohort technology is facing the challenges of cooling the advanced electronic devices with ever greater heat generated due to the densely populated Integrated Circuits (ICs). The commonly used cooling fluids like water, Ethylene Glycol (EG) and oils are not in the position to combat these challenges. To cater these requirements, advance fluids with better thermo physical properties called nano fluids are searched out which are the combination of base fluids and dispersed nano sized particles. Mini/Micro channel heat sinks using Nano fluids are the focus of the recent research. The current study is focused on the review of experimental, numerical and analytical application of the Nano fluids in mini/micro channel Heat sinks for enhanced heat transfer in cooling systems. The uses of Hybrid Nano fluids in different systems are also critically analysed. A brief discussion of porous medium devices, discussion of the correlations developed by different researchers for Hybrid nanofluids and synthesis as well as uses of super hydrophobic surfaces have also been included in this study

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. A multilayer graphene (MLG) coating was grown on a nickel substrate by atmospheric chemical vapor deposition (CVD). The macroscale dry sliding friction behavior of the coated specimens against a stainless steel counterface was investigated under various contact loads ranging from 1 N to 5 N and at various rotational speeds from 30 rpm to 240 rpm. After the tests, the sliding surfaces were characterized by optical and scanning electron microscopes and Raman spectroscopy. The results show that contact load and sliding speed had significant effects on the lubricity of the MLG coatings under dry sliding conditions. At relatively low contact loads (1-3 N) and sliding speeds (30-120 rpm), the MLG coating exhibited good lubricity with coefficient of friction (COF) below 0.06 and lasted a long period of sliding time for more than 3600 cycles. With increasing contact loads and speeds, the COF of the MLG coating was gradually increased and the coating suffered from sudden breakdown after limited sliding cycles, losing its lubricity. Detailed examination and analysis revealed that material transfer occurred at the early stage of the sliding process, where MLG was transferred from the coating surface to the counterface. This graphene transfer was responsible for the lubricity of the sliding pair and the sustainability of the transferred material on the counterface determined the lifetime of the lubricity regime. High contact loads and high speeds favored severe plastic deformation and mechanical damages of the substrate, which limited the lifetime of the transferred material and thus the lifetime of the lubricity regime. Sliding induced defects in the MLG both on the coating and on the counterface were confirmed by Raman spectroscopy.

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. The energy performance of buildings is a key point to achieve the sustainability goals of the modern world. The reduction of the heat loss by incorporating porosity in a monolithic material was studied. To this aim, lattice structures with varying lattice topology and specimen size were synthesised using polymer based additive manufacturing. Commercially available 3D printers and polymer filaments were utilised to manufacture such polymer lattices. Commercially available 3D printers and polymer filaments were utilised to manufacture such polymer lattices. Their thermal performance was characterised using a bespoke compact temperature-change hot chamber. A scaling law, based on the experimental results, has been proposed for the first time to predict the U-value of polymer lattices by correlating their effective thermal conductivities. It was observed that the lattice’s relative density and the sizes of a unit cell and specimen affected significantly the U-value. Also, it was found that polymer-lattice structures can be designed to only allow a conductive mode of heat transfer when their hydraulic diameter was less than 8 mm. The effect of an AM process parameters such as the layer thickness and type of 3D printer on the U-value of the polymer lattices was also characterised and found that they had a mild effect on the U-value of the lattices. Thus, a highly optimised lattice structure, aiming at achieving the higher thermal resistance to make it suitable for energy saving applications, can be obtained using the proposed scaling law.

Careful heat-transfer measurements have been conducted for condensation of steam-ethanol mixtures in vertical downflow over a horizontal, water-cooled, low-finned copper tube. Care was taken to avoid error due to the presence of air in the vapor. The tube had diameter at the fin root 12.7 mm and rectangular section fins with height 1.6 mm, thickness 0.5 mm and space between fins 1.0 mm. Tests were conducted at pressures of atmospheric, 55 kPa and 14 kPa. Concentrations of ethanol by mass in the boiler when cold prior to start up were 0.025%, 0.05%, 0.1%, 0.5% and 1.0%. The highest vapor velocity at approach to the tube was 7.5 m/s at atmospheric pressure and 15.0 m/s at vapor pressure 14 kPa. Effects of ethanol concentration on both retention angle and heat transfer were measured. The retention angle was strongly dependent on the vapor velocity and ethanol concentration which affected the condensation rate, composition and temperature of the condensate at the interface and consequently the surface tension of condensate. The results are compared with data for pure steam on the same finned tube and Marangoni condensation on a smooth tube under the same conditions. Similarly, results for condensate retention of water on finned tube are compared with earlier data and theoretical model. Vapor-side, heat-transfer coefficients were obtained by subtraction of coolant side and test tube wall thermal resistances from overall measurements.

The definition of nonwovens is even more complicated. The term nonwoven refers to web-like assemblages of fibers wherein fiber-to-fiber bonding replaces twisting and interlacing. We define a nonwoven as an engineered fabric structure that may contain fibrous and nonfibrous elements and that is often manufactured directly from fibers or filaments and may incorporate other types of fabrics. The difference primarily between a nonwoven and its more traditional counterparts (woven, knitted, and braided structures) is the structure. The fibers or filaments in a nonwoven are not interlaced or interlooped and are somewhat random layered assemblies of fibers held together by a variety of different means. The structure of a nonwoven is defined, therefore, as its fiber orientation distribution function (ODF). Another structural aspect important to consider is the basis weight (mass per unit area—g/m2 or more commonly referred to as gsm) and its uniformity. While ODF may dictate behavior, basis weight uniformity dictates failure. The structure-property relationships in a nonwoven cannot be decoupled from the process utilized to form the nonwoven. Therefore, below, we present a short review of the processes employed in the making of nonwovens followed by a discussion of the structure-process-property relationships and will make an attempt to describe the mechanical properties of one class of nonwovens.

Long-term durability of the vacuum edge seal plays a significant part in retrofitting triple vacuum glazing (TVG) to existing buildings in achieving progress towards a zero-energy building (ZEB) target. Vacuum pressure decrement with respect to time between panes affects the thermal efficiency of TVG. This study reports a 3D finite element model, with validated mathematical methods and comparison, for the assessment of the influence of vacuum pressure diminution on the thermal transmittance (U value) of TVG. The centre-of-pane and total U values of TVG are calculated to be 0.28 Wm&minus, 2 K&minus, 1 and 0.94 Wm&minus, 1 at the cavity vacuum pressure of 0.001 Pa. The results suggest that a rise in cavity pressure from 0.001 Pa to 100 kPa increases the centre-of-pane and total U values from 0.28 Wm&minus, 1 to 2.4 Wm&minus, 1 and 2.58 Wm&minus, 1, respectively. The temperature descent on the surfaces of TVG between hot and cold sides increases by decreasing the cavity vacuum pressure from 50 kPa to 0.001 Pa. Nonevaporable getters will maintain the cavity vacuum pressure of 0.001 Pa for over 20 years of life span in the cavity of 10-mm wide edge-sealed triple vacuum glazing, and enable the long-term durability of TVG.

This work was done in collaboration with colleagues from the institute of Engineering sciences and Architecture Research Institute The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. Globalisation has brought a number of challenges to the fore, particularly those problems which require collaboration, innovation and capability development between nations. There are some complex issues piquing the attention of researchers with respect to sustainable development, such as, waste management, climate change, and access to amenities, housing or education. Non-Governmental Organisations, Institutions, governments and others working in the field of international development have been grappling with these difficulties for decades. However, it is becoming apparent that many of these difficulties require multifaceted solutions, particularly in Low and Middle Income countries (LMIC) where it is difficult to consolidate gains and fund schemes. Development work can sometimes be disjointed and inefficient, impairing the capability of local communities and inhibiting sustainable and innovative approaches. Transdisciplinary collaboration is reliably a more efficient way of tackling some of the most pertinacious challenges. This paper presents findings from a transdisciplinary research project focussed on developing resources and capacity for the construction of affordable homes in a low income community in Nigeria. The project explored the suitability of using upcycled materials such as plastic bottles and agricultural waste in construction. Using a user-centred, co-creation methodology, a team of experts from the UK and Nigeria worked with local entrepreneurs to build a prototype home. The study explores the functionality of the home and the sustainability of project. The findings demonstrate the benefits of tackling global challenges from a transdisciplinary perspective. This has implications for researchers focused on developing technical solutions for low-income communities.