• Millimetre-wave antennas and systems for the future 5G

      Ur-Rehman, Masood; Abbasi, Qammer Hussain; Rahman, Atiqur; Khan, Imdad; Chattha, Hassan Tariq; Abdul Matin, Mohammad; University of Bedfordshire; Texas A & M University at Qatar; University of Glasgow; North South University, Dhaka; et al. (Hindawi, 2017-04-10)
      Editorial of the special issue on Millimetre-Wave Antennas and Systems for the Future 5G
    • Minimal mean-square error for 3D MIMO beamforming weighting

      Xu, C.; Cosmas, John; Zhang, Yue; Brunel University; University of Bedfordshire (Institution of Engineering and Technology, 2016-11-24)
      The 3D MIMO beamforming system needs a weighting method to determine the direction of beam whist reducing the interference for other beam areas operating at the same carrier frequency. The challenge is to determine the weights of the 3D MIMO beams to direct each beam towards its cluster of user terminals while placing its nulls at undesired user directions to minimise undesired interference. Therefore, the signal-to-interference-plus-noise ratio should be increased while the interference from the side lobes of the other beams reduced. A weight determining method is presented that constructs horizontal and vertical array weights, respectively, by minimising the mean-square error between the array pattern vector and the unit vector, where the unit vector expresses the desired direction for the array pattern and zero vector expresses the undesired direction. Since the rectangular planar array can be viewed as M linear arrays of N elements, the weight of the M–Nth element can be obtained based on the horizontal and vertical array weights.
    • Multi-channel SPR biosensor based on PCF for multi-analyte sensing applications

      Otupiri, R.; Akowuah, Emmanuel K.; Haxha, Shyqyri; Kwame Nkrumah University of Science & Technology, Ghana; University of Bedfordshire (Optical Society of America, 2015-06-15)
      This paper presents a theoretical investigation of a novel holey fiber (Photonic Crystal Fiber (PCF)) multi-channel biosensor based on surface plasmon resonance (SPR). The large gold coated micro fluidic channels and elliptical air hole design of our proposed biosensor aided by a high refractive index over layer in two channels enables operation in two modes; multi analyte sensing and self-referencing mode. Loss spectra, dispersion and detection capability of our proposed biosensor for the two fundamental modes ( x 11 HE and y 11 HE ) have been elucidated using a Finite Element Method (FEM) and Perfectly Matching Layers (PML).
    • Multi-parameter AFM characterization of INS-1 cells

      Yang, Fan; Wang, Bowei; Wang, Jiajia; Chen, Yujuan; Wang, Zuobin; Changchun University of Science and Technology; University of Bedfordshire (IEEE, 2021-11-18)
      AFM-based single cell force spectroscopy has been employed wildly, while more work is needed for the mechanical detection of diabetes-related cells (INS-1 cells). In this study, a multi-parameter AFM characterization was performed to detect the mechanical properties of INS-1 cells in situ. High resolution topographies and concurrent mechanics were obtained by taking the advantage of the quantitatively imaging (QI) mode AFM. The analyses of force curves and force maps jointly presented the multiple parameters involved in the cell mechanics. The AFM force spectroscopy measurement provides full analysis and comprehensive understanding of cell mechanics.
    • Multiband split-ring resonator based planar inverted-F antenna for 5G applications

      Ishfaq, Muhammad Kamran; Rahman, Tharek Abd; Chattha, Hassan Tariq; Ur-Rehman, Masood; Universiti Teknologi Malaysia; Government College University, Faisalabad; Islamic University in Madinah; University of Bedfordshire (Hindawi, 2017-03-21)
      5G, the fifth generation of wireless communications, is focusing on multiple frequency bands, such as 6GHz, 10GHz, 15GHz, 28GHz, and 38GHz, to achieve high data rates up to 10 Gbps or more.The industry demands multiband antennas to cover these distant frequency bands, which is a task much more challenging. In this paper, we have designed a novel multiband split-ring resonator (SRR) based planar inverted-F antenna (PIFA) for 5G applications. It is composed of a PIFA, an inverted-L parasitic element, a rectangular shaped parasitic element, and a split-ring resonator (SRR) etched on the top plate of the PIFA.The basic PIFA structure resonates at 6GHz. An addition of a rectangular shaped parasitic element produces a resonance at 15GHz. The introduction of a split-ring resonator produces a band notch at 8GHz, and a resonance at 10GHz, while the insertion of an inverted-L shaped parasitic element further enhances the impedance bandwidth in the 10GHz band. The frequency bands covered, each with more than 1GHz impedance bandwidth, are 6GHz (5–7GHz), 10GHz (9–10.8GHz), and 15GHz (14-15GHz), expected for inclusion in next-generation wireless communications, that is, 5G. The design is simulated using Ansys Electromagnetic Suite 17 simulation software package.The simulated and the measured results are compared and analyzed which are generally in good agreement.
    • A novel disparity-assisted block matching-based approach for super-resolution of light field images

      Farag, Saber; Velisavljević, Vladan; University of Bedfordshire (IEEE, 2018-06-01)
      Currently, available plenoptic imaging technology has limited resolution. That makes it challenging to use this technology in applications, where sharpness is essential, such as film industry. Previous attempts aimed at enhancing the spatial resolution of plenoptic light field (LF) images were based on block and patch matching inherited from classical image super-resolution, where multiple views were considered as separate frames. By contrast to these approaches, a novel super-resolution technique is proposed in this paper with a focus on exploiting estimated disparity information to reduce the matching area in the super-resolution process. We estimate the disparity information from the interpolated LR view point images (VPs). We denote our method as light field block matching super-resolution. We additionally combine our novel super-resolution method with directionally adaptive image interpolation from [1] to preserve sharpness of the high-resolution images. We prove a steady gain in the PSNR and SSIM quality of the super-resolved images for the resolution enhancement factor 8x8 as compared to the recent approaches and also to our previous work [2].
    • A novel fuzzy logic variable geometry turbocharger and exhaust gas recirculation control scheme for optimizing the performance and emissions of a diesel engine

      Cheng, Li; Dimitriou, Pavlos; Wang, William; Peng, Jun; Aitouch, Abdel; University of Sussex; National Institute of Advanced Industrial Science and Technology (AIST), Japan; University of Bedfordshire; Centre de Recherche en Informatique, Signal et Automatique de Lille (CRIStAL), France (SAGE, 2018-10-31)
      Variable geometry turbocharger and exhaust gas recirculation valves are widely installed on diesel engines to allow optimized control of intake air mass flow and exhaust gas recirculation ratio. The positions of variable geometry turbocharger vanes and exhaust gas recirculation valve are predominantly regulated by dual-loop proportional–integral–derivative controllers to achieve predefined set-points of intake air pressure and exhaust gas recirculation mass flow. The setpoints are determined by extensive mapping of the intake air pressure and exhaust gas recirculation mass flow against various engine speeds and loads concerning engine performance and emissions. However, due to the inherent nonlinearities of diesel engines and the strong interferences between variable geometry turbocharger and exhaust gas recirculation, an extensive map of gains for the P, I, and D terms of the proportional–integral–derivative controllers is required to achieve desired control performance. The present simulation study proposes a novel fuzzy logic control scheme to determine appropriate positions of variable geometry turbocharger vanes and exhaust gas recirculation valve in realtime. Once determined, the actual positions of the vanes and valve are regulated by two local proportional–integral–derivative controllers. The fuzzy logic control rules are derived based on an understanding of the interactions among the variable geometry turbocharger, exhaust gas recirculation, and diesel engine. The results obtained from an experimentally validated one-dimensional transient diesel engine model showed that the proposed fuzzy logic control scheme is capable of efficiently optimizing variable geometry turbocharger and exhaust gas recirculation positions under transient engine operating conditions in real-time. Compared to the baseline proportional–integral–derivative controllers approach, both engine’s efficiency and total turbo efficiency have been improved by the proposed fuzzy logic control scheme while NOx and soot emissions have been significantly reduced by 34% and 82%, respectively.
    • Numerical investigation on implementing Oxy-Fuel Combustion (OFC) in an ethanol-gasoline Dual-Fuel Spark Ignition (DFSI) engine

      Li, Xiang; Pei, Yiqiang; Ajmal, Tahmina; Rana, Khaqan-Jim; Aitouche, Abdel; Mobasheri, Raouf; Peng, Zhijun; University of Bedfordshire; Tianjin University; CRIStAL - Centre de Recherche en Informatique Signal et Automatique de Lille; et al. (Elsevier, 2021-06-08)
      To decrease even eliminate Carbon Dioxide (CO2) emissions for mitigating global warming, various technologies are being developed on combustion engines. In the research presented in this paper, a numerical investigation of Oxy-Fuel Combustion (OFC) technology on an ethanol-gasoline Dual-Fuel Spark Ignition (DFSI) engine under economical oxygen consumption at low and mid-high loads was performed by one-dimensional computer simulation. It is demonstrated that under OFC mode without other optimisation, Brake Mean Effective Pressure (BMEP) can meet the requirement at mid-high load, but it has a considerable decline at low load compared to Conventional Air Combustion (CAC) mode. Moreover, there is a considerable deterioration in Brake Specific Fuel Consumption (BSFC) compared to that of CAC mode. A practical method is proposed to optimise the DFSI engine performance under OFC mode by changing intake charge components and utilising appropriate Water Injection (WI) strategies. BMEP increases approximately 0.05 bar at low load. BSFC has a reduction of 3.35% and 1.82% at low load and mid-high load, respectively.
    • Numerical study on the effects of intake charge on oxy-fuel combustion in a dual-injection spark ignition engine at economical oxygen-fuel ratios

      Li, Xiang; Pei, Yiqiang; Peng, Zhijun; Ajmal, Tahmina; Rana, Khaqan-Jim; Aitouche, Abdel; Mobasheri, Raouf (SAGE, 2021-05-28)
      In order to decrease Carbon Dioxide (CO2) emissions, Oxy-Fuel Combustion (OFC) technology with Carbon Capture and Storage (CCS) is being developed in Internal Combustion Engine (ICE). In this article, a numerical study about the effects of intake charge on OFC was conducted in a dual-injection. Spark Ignition (SI) engine, with Gasoline Direct Injection (GDI), Port Fuel Injection (PFI) and P-G (50% PFI and 50% GDI) three injection strategies. The results show that under OFC with fixed Oxygen Mass Fraction (OMF) and intake temperature, the maximum Brake Mean Effective Pressure (BMEP) is each 5.671, 5.649 and 5.646 bar for GDI, P-G and PFI strategy, which leads to a considerable decrease compared to Conventional Air Combustion (CAC).
    • On the simultaneous inversion of micro-perforated panels' parameters: application to single and double air-cavity backed systems

      Tayong-Boumda, Rostand; Manyo Manyo, Jacques A.; Siryabe, Emmanuel; Ntamack, Guy E.; University of Bristol; Université de Ngaoundéré; Université du Havre (Acoustical Society of America, 2018-04-20)
      This study deals with the deduction of parameters of Micro-Perforated Panel (MPP) systems from impedance tube data. It is shown that there is an ambiguity problem that exists between the MPP thickness and its open area ratio. This problem makes it difficult to invert the reflection coefficient data fitting and therefore to deduct the MPP parameters. A technique is proposed to reduce this ambiguity by using an equation that links the hole diameter to the open area ratio. Reflection coefficient data obtained for two specimens with different characteristics is employed for searching the MPP parameters using a simulated annealing algorithm. The results obtained demonstrate the effectiveness of this technique.
    • Optical based noninvasive glucose monitoring sensor prototype

      Haxha, Shyqyri; Jhoja, Jaspreet; University of Bedfordshire (IEEE, 2016-12-13)
      Diabetes mellitus claims millions of lives every year. It affects the body in various ways by leading to many serious illnesses and premature mortality. Heart and kidney diseases, which are caused by diabetes, are increasing at an alarming rate. In this paper, we report a study of a noninvasive measurement technique to determine the glucose levels in the human body. Current existing methods to quantify the glucose level in the blood are predominantly invasive that involve taking the blood samples using finger pricking. In this paper, we report a spectroscopy-based noninvasive glucose monitoring system to measure glucose concentration. Near-infrared transmission spectroscopy is used and in vitro experiments are conducted, as well as in vivo. Our experimental study confirms a correlation between the sensor output voltage and glucose concentration levels. We report a low-cost prototype of spectroscopy-based noninvasive glucose monitoring system that demonstrates promising results in vitro and establishes a relationship between the optical signals and the changing levels of blood–glucose concentration.
    • Optical-based sensor prototype for continuous monitoring of the blood pressure

      Cohen, Zachary Joel Valentino; Haxha, Shyqyri; University of Bedfordshire (IEEE Sensors Journal, 2017-07-01)
      In this paper, we report a prototype ring sensor device for continuous measurement of blood pressure with the use of our, previously developed, heart rate monitoring ring device. An experiment is described where the heart rate device provides the voltage output of the heart using the transmission photoplethysmography (PPG) method and predicts the blood pressure’s value to ±5% of its true value. We report a novel potential non-invasive, low cost, continuous heart rate and blood pressure monitoring device that uses transmission PPG instead of the traditional cuff method to observe the changes in volume of the pressure through the arteries of the finger. The continuous samples are averaged out constantly. We employed the PPG technique to optically determine the blood volume changes in the arteries of the finger. A Pearson’s product moment correlation coefficient proved an r value of 0.86 showing strong linear correlation between the average voltage of the heart rate and the corresponding blood pressure. The proposed blood pressure ring sensor device was tested and benchmarked (against Nonin 2120 benchmark blood pressure device) four participants for a continuous period of four hours, where the average Mean Arterial Pressure (MAP) (using Nonin 2120) for four hours was at 98.92mmHg and the average predicted MAP was at 92.8mmHg, which demonstrates an accuracy of 93.8%.The average real systolic pressure (using Nonin 2120) was at 144.25mmHg and the predicted average systolic pressure was at 132.77mmHg which shows an accuracy of 92%. The average real diastolic pressure (using Nonin 2120) was at 76.25mmHg and the predicted diastolic pressure was 72.7mmHg, showing an accuracy of 95.5%. 
    • Optimisation of dispersion compensating in a long-haul fibre for RF transmission of up to 100Gbit/s by using RZ and NRZ formats

      Paloi, Fadil; Mirza, Taimur; Haxha, Shyqyri; University of Bedfordshire (Elsevier, 2016-12-02)
      With the recent data rate increase it is very challenging to build a fibre optic network that would enable a high data rate transmission over a long haul distance. The signal suffers large degradation over a certain distance due to distortion by the nonlinear effects of the optical fibres. In particular, transmission of high data rates over existing fibre optic systems, while keeping the cost low, avoiding an increase of the system’s complexity and the usage of expensive devices, would be a very challenging task. In this paper, we address this problem by increasing the transmission distance in the fibre optic links for up to 2500km. We have used Standard Single Mode Fibre (SSMF) and Dispersion Compensation Fibre (DCF), where DCF is used as a loss compensator in Radio-Over-Fibre (RoF) systems. A mixture combination of the pre, post and symmetrical fibre compensation schemes were developed to overcome the dispersion in the fibre. We have found that in order to achieve high RF over fibre optic system performance for high data rates and long transmission, there is a requirement to upgrade the optical configuration scheme in a proportional way, by raising the length of the fibre span, compensation span and amplification. We have reported optimised RF over fibre configuration schemes that would have a great impact on reducing the cost, reducing the system’s complexity and avoiding usage of expensive devices, in order to achieve high data rate transmission over existing fibre optic systems.
    • Optimising microscopic spray characteristics and particle emissions in a dual-injection spark ignition (SI) engine by changing GDI injection pressure

      Li, Xiang; Li, Dayou; Pei, Yiqiang; Peng, Zhijun; Tianjin University; University of Bedfordshire; University of Lincoln (SAGE, 2022-03-01)
      Regarding reducing particle emissions from dual-injection spark ignition engines, most of the existing research focused on the benefits of using alcohol fuels. However, a comprehensive study of the effects of fuel injection pressure on microscopic spray characteristics and particle emissions in dual-injection spark ignition engines fuelled with gasoline has not been reported before. In this paper, with the assistance of phase Doppler particles analyser system and fast particle analyser, a study of optimising microscopic spray characteristics and particle emissions in a dual-injection spark ignition engine fuelled with gasoline by changing GDI injection pressure was conducted. The results show that by increasing injection pressure from 5.5 MPa to 18 MPa, both normal and tangential components of droplet velocity increase, but the possibility of spray impingement would not increase a lot. Higher injection pressure would increase the probability of small droplets, and more droplets would collapse with a mode of continuous ripping or break down abruptly. From jet’s central axis to sides, Sauter mean diameter increases first, then reduces outside the spray boundary. Increasing injection pressure from 5.5 MPa to 18 MPa reduces total particle number concentration, which is 53.98% and 45.44% at 2 bar and 10 bar, respectively. Meanwhile, the peak of particle number distribution curve decreases from 3.01×106 to 1.43×106 at 2 bar, whilst reducing from 1.08×106 to 5.33×105 at 10 bar. Overall, this paper comprehensively analyses the effects of fuel injection pressure on microscopic spray characteristics and particle emissions, whilst offering a practical approach to reduce particle emissions in dual-injection SI engines fuelled with gasoline.
    • Oxy-fuel combustion for carbon capture and storage in internal combustion engines - a review

      Li, Xiang; Peng, Zhijun; Pei, Yiqiang; Ajmal, Tahmina; Rana, Khaqan-Jim; Aitouche, Abdel; Mobasheri, Raouf; ; University of Bedfordshire; Tianjin University; et al. (2021-08-18)
      As the impacts of global warming have become increasingly severe, oxy-fuel combustion has been widely considered a promising solution for carbon capture and storage (CCS) to reduce carbon dioxide (CO2) to achieve net-zero emissions. In the past few decades, researchers around the world have demonstrated improvements by the application of oxy-fuel combustion to internal combustion (IC) engines. This article presents a comprehensive review of the experimental and simulation studies about oxy-combustion for CCS in IC engines. To give a more comprehensive understanding, it has included a detailed explanation of the essential components contained in an oxy-fuel IC engine and its typical operating parameters. The oxy-fuel IC engine components include the system of oxygen supply, exhaust gas recirculation (EGR), water injection, fuel injection, and CCS. In order to optimise the combustion process, it is required to adopt the appropriate values for the oxygen concentration, EGR rate, ignition timing, compression ratio, fuel injection, and water injection in oxy-fuel engines. The detailed literature review and analysis presented provide a basis for the selection of oxy-fuel combustion for CCS as a prospective solution to reduce carbon emissions in IC engines.
    • Passive localization through light flicker fingerprinting

      Munir, Bilal; Dyo, Vladimir (IEEE, 2019-08-22)
      In this paper, we show that the flicker waveforms of various CFL and LED lamp models exhibit distinctive waveform patterns due to harmonic distortions of rectifiers and voltage regulators, the key components of modern lamp drivers. We then propose a passive localization technique based on fingerprinting these distortions that occur naturally in indoor environments and thus requires no infrastructure or additional equipment. The novel technique uses principal component analysis (PCA) to extract the most important signal features from the flicker frequency spectra followed by kNN clustering and neural net- work classifiers to identify a light source based on its flicker signature. The evaluation on 39 flicker patterns collected from 8 residential locations demonstrates that the technique can identify a location within a house with up to 90% accuracy and identify an individual house from a set of houses with an average accuracy of 86.3%.
    • Pulse oximetry optical sensor using oxygenbound haemoglobin

      Cohen, Zachary Joel Valentino; Haxha, Shyqyri; Aggoun, Amar; University of Bedfordshire (Optical Society of America, 2016-05-02)
      In this paper we report a unique approach to measuring oxygen saturation levels by utilising the wavelength of the haemoglobin instead of the conventional absorption difference. Two experiments are set up to measure the wavelength of the haemoglobin bound to oxygen at different oxygen saturation levels with the help of a spectrometer. We report a unique low cost and robust wavelength monitoring SpO2 sensor that measures the SpO2 by using the colour of the blood and not the absorption difference of oxyhaemoglobin and deoxyhaemoglobin. With use of a spectrometer, we show that the wavelength of the oxygen-bound haemoglobin has a relation to the oxygen saturation level. The proposed device is designed and experimentally implemented with a colour sensor to measure the SpO2 level of the blood.
    • Real-time refocusing using an FPGA-based standard plenoptic camera

      Hahne, Christopher; Lumsdaine, Andrew; Aggoun, Amar; Velisavljević, Vladan; University of Bedfordshire; Pacific Northwest National Laboratory (IEEE, 2018-03-22)
      Plenoptic cameras are receiving increased attention in scientific and commercial applications because they capture the entire structure of light in a scene, enabling optical transforms (such as focusing) to be applied computationally after the fact, rather than once and for all at the time a picture is taken. In many settings, real-time inter active performance is also desired, which in turn requires significant computational power due to the large amount of data required to represent a plenoptic image. Although GPUs have been shown to provide acceptable performance for real-time plenoptic rendering, their cost and power requirements make them prohibitive for embedded uses (such as in-camera). On the other hand, the computation to accomplish plenoptic rendering is well structured, suggesting the use of specialized hardware. Accordingly, this paper presents an array of switch-driven finite impulse response filters, implemented with FPGA to accomplish high-throughput spatial-domain rendering. The proposed architecture provides a power-efficient rendering hardware design suitable for full-video applications as required in broadcasting or cinematography. A benchmark assessment of the proposed hardware implementation shows that real-time performance can readily be achieved, with a one order of magnitude performance improvement over a GPU implementation and three orders ofmagnitude performance improvement over a general-purpose CPU implementation.
    • A review of fuel cell technology for commercial vehicle applications

      Jokela, Tommi; Kim, Bill; Gao, Bo; Wellers, Matthias; Peng, Zhijun (Inderscience, 2021-12-31)
      The demanding energy storage requirements of many commercial vehicle applications are extremely difficult to meet for pure battery electric vehicles (BEVs) due to the limited energy density of batteries. Fuel cells appear to be the only viable propulsion technology that is able to meet commercial vehicle powertrain requirements with zero local greenhouse gas emissions. Since almost all fuel cell vehicles (FCVs) contain a high voltage battery, some additional complexity is introduced since the hybrid energy storage system must be sized and controlled appropriately. An understanding of the strengths and weaknesses of each system is therefore essential in FCV design. The aim of this technology review is to provide an overview of fuel cell technologies in commercial vehicle applications including assessments of alternative powertrain and fuel cell types, advantages and disadvantages of fuel cell and battery systems and the implications of these on the powertrain sizing as well as control considerations of FCVs.
    • Review of machine learning based fault detection for centrifugal pump induction motors

      Sunal, Cem Ekin; Dyo, Vladimir; Velisavljevic, Vladan; ; University of Bedfordshire (IEEE, 2022-07-01)
      Centrifugal pumps are an integral part of many industrial processes and are used extensively in water supply, sewage, heating and cooling systems. While there are several review papers on machine learning-based fault diagnosis on induction motors, its application to centrifugal pumps has received relatively little attention. This work attempts to summarize and review recent research and development in machine learning-based pump condition monitoring and fault diagnosis. The paper starts with a brief explanation of pump operation including common pump faults and the main principles of the motor current signature analysis (MCSA) method. This is followed by a detailed explanation of various machine learning-based methods including the types of detected faults, experimental details and reported accuracies. The performances of different approaches are then presented systematically in a unified table. Finally, the authors discuss practical aspects and challenges related to data collection, storage and real-world implementation.