• Investigation of Plasma Treatment on Micro-Injection Moulded Microneedle for Drug Delivery

      Nair, Karthik Jayan; Whiteside, Benjamin R.; Grant, Colin A.; Patel, Rajnikant; Tuinea-Bobe, Cristina-Luminita; Norris, Keith; Paradkar, Anant R. (2015-10-30)
      Plasma technology has been widely used to increase the surface energy of the polymer surfaces for many industrial applications; in particular to increase in wettability. The present work was carried out to investigate how surface modification using plasma treatment modifies the surface energy of micro-injection moulded microneedles and its influence on drug delivery. Microneedles of polyether ether ketone and polycarbonate and have been manufactured using micro-injection moulding and samples from each production batch have been subsequently subjected to a range of plasma treatment. These samples were coated with bovine serum albumin to study the protein adsorption on these treated polymer surfaces. Sample surfaces structures, before and after treatment, were studied using atomic force microscope and surface energies have been obtained using contact angle measurement and calculated using the Owens-Wendt theory. Adsorption performance of bovine serum albumin and release kinetics for each sample set was assessed using a Franz diffusion cell. Results indicate that plasma treatment significantly increases the surface energy and roughness of the microneedles resulting in better adsorption and release of BSA.
    • Investigation of Pulse electric field effect on HeLa cells alignment properties on extracellular matrix protein patterned surface

      Jamil, M. Mahadi Abdul; Zaltum, M.A.M.; Rahman, N.A.A.; Ambar, R.; Denyer, Morgan C.T.; Javed, F.; Sefat, Farshid; Mozafari, M.; Youseffi, Mansour (2018)
      Cell behavior in terms of adhesion, orientation and guidance, on extracellular matrix (ECM) molecules including collagen, fibronectin and laminin can be examined using micro contact printing (MCP). These cell adhesion proteins can direct cellular adhesion, migration, differentiation and network formation in-vitro. This study investigates the effect of microcontact printed ECM protein, namely fibronectin, on alignment and morphology of HeLa cells cultured in-vitro. Fibronectin was stamped on plain glass cover slips to create patterns of 25μm, 50μm and 100μm width. However, HeLa cells seeded on 50μm induced the best alignment on fibronectin pattern (7.66° ±1.55SD). As a consequence of this, 50μm wide fibronectin pattern was used to see how fibronectin induced cell guidance of HeLa cells was influenced by 100μs and single pulse electric fields (PEF) of 1kV/cm. The results indicates that cells aligned more under pulse electric field exposure (2.33° ±1.52SD) on fibronectin pattern substrate. Thus, PEF usage on biological cells would appear to enhance cell surface attachment and cell guidance. Understanding this further may have applications in enhancing tissue graft generation and potentially wound repair.
    • Investigation of routing reliability of vehicular ad hoc networks

      Eiza, M.H.; Ni, Q.; Owens, T.; Min, Geyong (2013-07-01)
      In intelligent transportation systems, the cooperation between vehicles and the road side units is essential to bring these systems to fruition. Vehicular ad hoc networks (VANETs) are a promising technology to enable the communications among vehicles on one hand and between vehicles and road side units on the other hand. However, it is a challenging task to develop a reliable routing algorithm for VANETs due to the high mobility and the frequent changes of the network topology. Communication links are highly vulnerable to disconnection in VANETs; hence, the routing reliability of these ever-changing networks needs to be paid special attention. In this paper, we propose a new vehicular reliability model to facilitate the reliable routing in VANETs. The link reliability is defined as the probability that a direct communication link between two vehicles will stay continuously available over a specified time period. Furthermore, the link reliability value is accurately calculated using the location, direction and velocity information of vehicles along the road. We extend the well-known ad hoc on-demand distance vector (AODV) routing protocol to propose our reliable routing protocol AODV-R. Simulation results demonstrate that AODV-R outperforms significantly the AODV routing protocol in terms of better delivery ratio and less link failures while maintaining a reasonable routing control overhead.
    • Investigation of Simultaneous Effects of Surface Roughness, Porosity, and Magnetic Field of Rough Porous Microfin Under a Convective-Radiative Heat Transfer for Improved Microprocessor Cooling of Consumer Electronics

      Oguntala, George A.; Sobamowo, G.; Eya, Nnabuike N.; Abd-Alhameed, Raed A. (2019-02)
      The ever-increasing demand for high-processing electronic systems has unequivocally called for improved microprocessor performance. However, increasing microprocessor performance requires increasing power and on-chip power density, both of which are associated with increased heat dissipation. Electronic cooling using fins have been identified as a reliable cooling approach. However, an investigation into the thermal behaviour of fin would help in the design of miniaturized, effective heatsinks for reliable microprocessor cooling. The aim of this paper is to investigates the simultaneous effects of surface roughness, porosity and magnetic field on the performance of a porous micro-fin under a convective-radiative heat transfer mechanism. The developed thermal model considers variable thermal properties according to linear, exponential and power laws, and are solved using Chebychev spectral collocation method. Parametric studies are carried using the numerical solutions to establish the influences of porosity, surface roughness, and magnetic field on the microfin thermal behaviour. Following the results of the simulation, it is established that the thermal efficiency of the micro-fin is significantly affected by the porosity, magnetic field, geometric ratio, nonlinear thermal conductivity parameter, thermogeometric parameter and the surface roughness of the micro-fin. However, the performance of the micro-fin decreases when it operates only in a convective environment. In addition, we establish that the fin efficiency ratio which is the ratio of the efficiency of the rough fin to the efficiency of the smooth fin is found to be greater than unity when the rough and smooth fins of equal geometrical, physical, thermal and material properties are subjected to the same operating condition. The investigation establishes that improved thermal management of electronic systems would be achieved using rough surface fins with porosity under the influences of the magnetic field.
    • Investigation of stick-slip vibration in a commercial vehicle brake assembly

      Ashraf, N.; Bryant, David; Fieldhouse, John D. (2017-09)
      There are several types of disc brake instabilities associated with the brake systems; however, they are usually classified into two main categories depending on the frequency range: brake groan 0–300 Hz and brake squeal 1– 16 kHz. The groan is associated with the stick-slip motion while the squeal is associated with the modal coupling. This paper presents a detailed analysis of low frequency noise (0–300 Hz) in a commercial vehicle trailer disc brake as a result of stick-slip vibration. A range of experimental techniques are used to understand the characteristic behaviour of the caliper and the brake pads during braking events on a laboratory test rig. The analysed brake system comprised a full disc brake assembly and the trailer suspension system with a beam axle. Laser-based optical displacement sensors were used to investigate the deformation of the caliper body and the brake pads during a braking application. The contact pressure distribution at the disc/pad interfaces were also measured to gain more insight into the contact profile of the pad surfaces. Results revealed that the stick-slip phenomenon, in this study, was a result of the combination of the deformation of the caliper and the friction material formulation of the brake pads. In addition, it was observed through the testing of two different sets of pads that a low compression modulus would help to reduce the stick-slip phenomenon.
    • Investigation of the Applicability of an e-Portfolio Tool to Support Final Year Engineering Projects.

      Sheriff, Ray E.; Ong, Felicia Li Chin (14/03/2012)
      This project investigated the extent to which e-portfolio tools can be applied to final year engineering projects with a view to supporting the experience from the perspective of supervisor and student respectively. E-portfolio tools allow students to generate, store and share evidence, minute meetings and record reflections as well as helping them to develop generic professional engineering skills. The research methodology combined qualitative and quantitative techniques. Semi-structured face-to-face interviews with eight supervisors and online questionnaires completed by 13 supervisors and 31 students provided the basis for the research. Training on the university¿s e-portfolio tool was provided for 19 members of staff, while a seminar introducing the project to the final year cohort was attended by 33 students. To conclude, an e-portfolio application was made available to students.
    • Investigation of the applicability of an e-portfolio tool to support final year engineering projects.

      Sheriff, Ray E.; Ong, Felicia Li Chin (2012-07)
      This project investigated the extent to which e-portfolio tools can be applied to final year engineering projects with a view to supporting the experience from the perspective of supervisor and student respectively. E-portfolio tools allow students to generate, store and share evidence, minute meetings and record reflections as well as helping them to develop generic professional engineering skills. The research methodology combined qualitative and quantitative techniques. Semi-structured face-to-face interviews with eight supervisors and online questionnaires completed by 13 supervisors and 31 students provided the basis for the research. Training on the university's e-portfolio tool was provided for 19 members of staff, while a seminar introducing the project to the final year cohort was attended by 33 students. To conclude, an e-portfolio application was made available to students.
    • Investigation of the Applicability of an E-Portfolio Tool to Support Final Year Engineering Projects. [Poster presentation].

      Sheriff, Ray E.; Ong, Felicia Li Chin (15/09/2011)
      The Royal Academy of Engineering, together with the Higher Education Academy Engineering Subject Centre, organised one of the two Dissemination Seminars at University of Bradford. This event was for the project leaders of funded engineering projects under their three calls, opened between March 2010 and March 2011.
    • Investigation of the Growth of Particles Produced in a Laval Nozzle

      Zhalehrajabi, E.; Rahmanian, Nejat; Zarrinpashne, S.; Balasubramanian, P. (2014)
      This study focuses on numerical modeling of condensation of water vapor in a Laval nozzle, using the liquid drop nucleation theory. Influence of nozzle geometry, pressure, and temperature on the average drop size is reported. A computer program written in MATLAB was used used to calculate the nucleation and condensation of water vapor in the nozzle. The simulation results are validated with the available experimental data in the literature for steam condensation. The model reveals that the average drop size is reduced by increasing the divergent angle of the nozzle. The results also confirm that increasing the inlet pressure has a direct effect on the average drop size while temperature rise has an inverse effect on the drop size.
    • Investigation of the influence of vacuum venting on mould surface temperature in micro injection moulding

      Sorgato, M.; Babenko, Maksims; Lucchetta, G.; Whiteside, Benjamin R. (2016)
      The application of vacuum venting for the removal of air from mould cavity has been introduced in injection moulding with the intent to enhance micro/nano features replication and definition. The technique is adopted to remove air pockets trapped in the micro-features, which are out of reach for conventional venting technologies and can create considerable resistance to the melt filling flow. Nonetheless, several studies have revealed a negative effect on replication that could possibly arise from the application of vacuum venting. Although the incomplete filling of micro-scale features has often been attributed to poor venting, the limited research examining the application of vacuum venting has produced mixed results. In this work, the effect of air evacuation was experimentally investigated, monitoring mould and polymer temperature evolution during the micro injection moulding process by means of a high speed infrared camera and a sapphire window, which forms part of the mould wall. The results show that air evacuation removes a mould surface heating effect caused by rapid compression of the air ahead of the flow front and subsequent conduction of that heat into the mould surface. Hence, with the increase of the surface-to-volume ratio in micro-cavities, air evacuation has a detrimental effect on the cavity filling with polymers that are sensitive to changes of the mould temperature.
    • Investigation of the process energy demand in polymer extrusion: A brief review and an experimental study

      Abeykoon, Chamil; Kelly, Adrian L.; Brown, Elaine C.; Vera-Sorroche, Javier; Coates, Philip D.; Harkin-Jones, E.; Howell, Ken B.; Deng, J.; Li, K.; Price, M. (2014-12-31)
      Extrusion is one of the fundamental production methods in the polymer processing industry and is used in the production of a large number of commodities in a diverse industrial sector. Being an energy intensive production method, process energy efficiency is one of the major concerns and the selection of the most energy efficient processing conditions is a key to reducing operating costs. Usually, extruders consume energy through the drive motor, barrel heaters, cooling fans, cooling water pumps, gear pumps, etc. Typically the drive motor is the largest energy consuming device in an extruder while barrel/die heaters are responsible for the second largest energy demand. This study is focused on investigating the total energy demand of an extrusion plant under various processing conditions while identifying ways to optimise the energy efficiency. Initially, a review was carried out on the monitoring and modelling of the energy consumption in polymer extrusion. Also, the power factor, energy demand and losses of a typical extrusion plant were discussed in detail. The mass throughput, total energy consumption and power factor of an extruder were experimentally observed over different processing conditions and the total extruder energy demand was modelled empirically and also using a commercially available extrusion simulation software. The experimental results show that extruder energy demand is heavily coupled between the machine, material and process parameters. The total power predicted by the simulation software exhibits a lagging offset compared with the experimental measurements. Empirical models are in good agreement with the experimental measurements and hence these can be used in studying process energy behaviour in detail and to identify ways to optimise the process energy efficiency.
    • Investigation of the structural and mechanical properties of micro-/nano-sized Al2O3 and cBN composites prepared by spark plasma sintering

      Irshad, H.M.; Ahmed, B.A.; Ehsan, M.A.; Khan, Tahir I.; Laoui, T.; Yousaf, M.R.; Ibrahim, A.; Hakeem, A.S. (2017-10)
      Alumina-cubic boron nitride (cBN) composites were prepared using the spark plasma sintering (SPS) technique. Alpha-alumina powders with particle sizes of ∼15 µm and ∼150 nm were used as the matrix while cBN particles with and without nickel coating were used as reinforcement agents. The amount of both coated and uncoated cBN reinforcements for each type of matrix was varied between 10 to 30 wt%. The powder materials were sintered at a temperature of 1400 °C under a constant uniaxial pressure of 50 MPa. We studied the effect of the size of the starting alumina powder particles, as well as the effect of the nickel coating, on the phase transformation from cBN to hBN (hexagonal boron nitride) and on the thermo-mechanical properties of the composites. In contrast to micro-sized alumina, utilization of nano-sized alumina as the starting powder was observed to have played a pivotal role in preventing the cBN-to-hBN transformation. The composites prepared using nano-sized alumina reinforced with nickel-coated 30 wt% cBN showed the highest relative density of 99% along with the highest Vickers hardness (Hv2) value of 29 GPa. Because the compositions made with micro-sized alumina underwent the phase transformation from cBN to hBN, their relative densification as well as hardness values were relatively low (20.9–22.8 GPa). However, the nickel coating on the cBN reinforcement particles hindered the cBN-to-hBN transformation in the micro-sized alumina matrix, resulting in improved hardness values of up to 24.64 GPa.
    • Investigation of the Temperature Homogeneity of Die Melt Flows in Polymer Extrusion

      Abeykoon, Chamil; Martin, P.J.; Kelly, Adrian L.; Li, K.; Brown, Elaine C.; Coates, Philip D. (2014)
      Polymer extrusion is fundamental to the processing of polymeric materials and melt flow temperature homogeneity is a major factor which influences product quality. Undesirable thermal conditions can cause problems such as melt degradation, dimensional instability, weaknesses in mechanical/optical/geometrical properties, and so forth. It has been revealed that melt temperature varies with time and with radial position across the die. However, the majority of polymer processes use only single-point techniques whose thermal measurements are limited to the single point at which they are fixed. Therefore, it is impossible for such techniques to determine thermal homogeneity across the melt flow. In this work, an extensive investigation was carried out into melt flow thermal behavior of the output of a single extruder with different polymers and screw geometries over a wide range of processing conditions. Melt temperature profiles of the process output were observed using a thermocouple mesh placed in the flow and results confirmed that the melt flow thermal behavior is different at different radial positions. The uniformity of temperature across the melt flow deteriorated considerably with increase in screw rotational speed while it was also shown to be dependent on process settings, screw geometry, and material properties. Moreover, it appears that the effects of the material, machine, and process settings on the quantity and quality of the process output are heavily coupled with each other and this may cause the process to be difficult to predict and variable in nature. (C) 2013 Society of Plastics Engineers
    • Investigation of using photovoltaic system at local residential community level

      Ihbal, Abdel-Baset M.I.; Abd-Alhameed, Raed A.; Elgadal, M.A.; Gavasa, H.M.; Ehbal, M.M. (2014)
      The non-renewable fossil fuels are the foremost resources used to generate electricity and heat energy worldwide. The need to move towards Sustainable Community Renewable Energy solutions is highlighted by the increasing greenhouse gas emissions resulting from the use of fossil fuels. Local peoples could be involved in renewable projects to ensure a local community experiences benefits within relatively short time periods and could eventually contribute a significant amount of electricity into the energy market. In the UK, renewable energy generated on a local community rather than national can be considered as one of the key Solution of the global energy challenges and to establish a secure energy supply system. This paper aims to investigate the possibility of using renewable energy (RE) at community level. The evaluation of the cost-effectiveness of the building integrated photovoltaic roofing system when connected to the utility grid has been taken as an example. Using the current utility rates and the energy consumption data, the payback period of the system is evaluated.
    • Investigation of Voltage Stability Indices to Identify Weakest Bus (TBC).

      Jalboub, Mohamed K.; Rajamani, Haile S.; Liang, D.T.W.; Abd-Alhameed, Raed A.; Ihbal, Abdel-Baset M.I. (2010)
      This paper proposes a new index to determine the static voltage stability of the load buses in a power network for certain operating conditions and hence identifies load buses which are close to voltage collapse. The proposed index is formulated from the quadratic equation derived from a two-bus network and is computed using the apparent power and the line impedance. The proposed index shows how far the load buses from their voltage stability limit and hence the most sensitive bus can be identified according to maximum loadability. 14 bus IEEE reliability test system is used to study the performance of the proposed index for its validity. A comparison is also made between proposed index and some other indices found in the literature. The results are discussed and key conclusion drawn.
    • An investigation on process of seeded granulation in a continuous drum granulator using DEM

      Behjani, M.A.; Rahmanian, Nejat; Ghani N.F.b.A.; Hassanpour, A. (2017)
      Numerical simulation of wet granulation in a continuous granulator is carried out using Discrete Element Method (DEM) to discover the possibility of formation of seeded granules in a continuous process with the aim of reducing number of experimental trials and means of process control. Simple and scooped drum granulators are utilized to attain homogenous seeded granules in which the effects of drum rotational speed, particles surface energy, and particles size ratio are investigated. To reduce the simulation time a scale-up scheme is designed in which a dimensionless number (Cohesion number) is defined based on the work of cohesion and gravitational potential energy of the particles. Also a mathematical/numerical method along with a MATLAB code is developed by which the percentage of surface coverage of each granule is predicted precisely. The results show that use of continuous granulator is promising provided that a high level of shear is considered in the granulator design, e.g. it is observed that using baffles inside the drum granulators is essential for producing seeded granules. It is observed, moreover, that the optimum surface energy for scooped granulator with rotational speed of 50 rpm is 3 J/m2 which is close to the number predicted by Cohesion number. It is also shown that increasing the seed/fine size ratio enhances the seeded granulation both quantitatively (60% increase in seeds surface coverage) and qualitatively (more homogeneous granules).
    • Investigation on scour protection of submarine piggyback pipeline

      Yang, S.; Shi, B.; Guo, Yakun; Yang, L. (2019-06-15)
      This paper presents the results of laboratory experiments and numerical simulations to investigate the effect of different piggyback pipeline configuration on the morphology of local seabed scour subject to steady currents. Piggyback pipeline configuration investigated includes the commonly used piggyback pipeline, namely a small pipe attached on the top of large pipe and new form of piggyback pipeline proposed in this study in which a small pipe is attached to the large pipe on the upstream and downstream side, respectively. Pressure gradient, drag coefficient, lift coefficient and scour extent around pipelines are measured and analyzed for a range of pipelines and current conditions. Results show that the vortex strength downstream of the commonly used piggyback pipeline is larger than that for a single as well as the new piggyback pipeline under the same condition. This new type piggyback pipeline can effectively reduce the depth and width of the scour hole. In particular, when the ratio of the small pipe diameter over the large pipe diameter is greater than 0.3, little scour under this new type piggyback pipeline occurs for the test conditions. The bed topography downstream of the pipe has also been altered to favor the backfill.
    • Investigation on scour scale of piggyback pipeline under wave conditions

      Yang, S.; Shi, B.; Guo, Yakun (2019-06-15)
      Laboratory experiments are presented to investigate the effect of different piggyback pipeline configurations on the morphology of local scour under wave conditions. Scour depth and width around the pipelines under regular and irregular waves are measured and analyzed for a range of pipeline and wave conditions; such as the spacing between two pipes (G), gap between the main pipe and seabed (e), pipe diameter (D), wave height (H) and period (T). Experimental results reveal that both the scour depth and width around piggyback pipeline is much larger than those around single pipe under the same wave conditions. Scour depth increases with the increase of the Keulegan-Carpenter (KC) number and decreases with increase of G and e. When e exceeds 0.5D, scour depth tends to approach 0.When spacing G is greater than 0.4D, the destabilization from small pipe to large one is greatly reduced, resulting in scour depth around piggyback pipeline being close to that around single pipe. Similar to scour depth, scour width broadens with the increase of KC number increasing and decreases with the increase of G. Experiments also show that the effect of e on scour depth is greater than that of G under the same test conditions, while their impact on scour width is opposite. Furthermore, scour width under irregular waves is extended slightly compared with regular wave for otherwise the identical conditions.
    • Investigations of polarisation purity and SAR for personal satellite communications antennas using a hybrid computational method

      Mangoud, Mohab A.; Abd-Alhameed, Raed A.; Excell, Peter S. (2001)
      The use of the hybrid method of moments/finite difference time domain technique can be effective for solution of electromagnetic problems which are intractable for a single numerical method. Using this method, a study of the effects of human proximity on the polarisation purity of different types of circularly-polarised handset antennas for personal satellite communications was undertaken. Associated with this, assessments of the specific absorption rate in the head were made. The method gave stable results, in accordance with physical expectations; good agreement with the pure method of moments was shown in simplified cases omitting the head
    • An IoT-enabled Decision Support System for Circular Economy Business Model

      Mboli, Julius S.; Thakker, Dhaval; Mishra, J. (Wiley, 2021)
      The traditional linear economy using a take‐make‐dispose model is resource intensive and has adverse environmental impacts. Circular economy (CE) which is regenerative and restorative by design is recommended as the business model for resource efficiency. While there is a need for businesses and organisations to switch from linear to CE, there are several challenges that needs addressing such as business models and the criticism of CE projects often being small scale. Technology can be an enabler toward scaling up CE; however, the prime challenge is to identify technologies that can allow predicting, tracking and proactively monitoring product's residual value to motivate businesses to pursue circularity decisions. In this paper, we propose an IoT‐enabled decision support system (DSS) for CE business model that effectively allows tracking, monitoring, and analysing products in real time with the focus on residual value. The business model is implemented using an ontological model. This model is complemented by a semantic decision support system. The semantic ontological model, first of its kind, is evaluated for technical compliance. We applied DSS and the ontological model in a real‐world use case and demonstrate viability and applicability of our approach.