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An artificial intelligence-assisted low-cost portable device for the rapid detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is presented here. This standalone temperature-controlled device houses tubes designed for conducting reverse transcription loop-mediated isothermal amplification (RT-LAMP) assays. Moreover, the device utilises tubes illuminated by LEDs, an in-built camera, and a small onboard computer with automated image acquisition and processing algorithms. This intelligent device significantly reduces the normal assay run time and removes the subjectivity associated with operator interpretation of colourimetric RT-LAMP results. To further improve this device’s usability, a mobile app has been integrated into the system to control the LAMP assay environment and to visually display the assay results by connecting the device to a smartphone via Bluetooth. This study was undertaken using ~5000 images produced from the ~200 LAMP amplification assays using the prototype device. Synthetic RNA and a small panel of positive and negative SARS-CoV-2 patient samples were assayed for this study. State-of-the-art image processing and artificial intelligence algorithms were applied to these images to analyse them and to select the most efficient algorithm. The template matching algorithm for image extraction and MobileNet CNN architecture for classification results provided 98.0% accuracy with an average run time of 20 min to confirm the endpoint result. Two working points were chosen based on the best compromise between sensitivity and specificity. The high sensitivity point has a sensitivity value of 99.12% and specificity value of 70.8%, while at the high specificity point, the sensitivity is 96.05% and specificity 93.59%. Furthermore, this device provides an efficient and cost-effective platform for non-health professionals to detect not only SARS-CoV-2 but also other pathogens in resource-limited laboratories, factories, airports, schools, universities, and homes.
Mukunthan Tharmakulasingam; Nouman S. Chaudhry; Anil Fernando; Manoharanehru Branavan; Wamadeva Balachandran; Aurore C. Poirier; Mohammed A. Rohaim; Muhammad Munir; Roberto M. La Ragione. An Artificial Intelligence-Assisted Portable Low-Cost Device for the Rapid Detection of SARS-CoV-2. Electronics 2021, 10, 2065 .
AMA StyleMukunthan Tharmakulasingam, Nouman S. Chaudhry, Anil Fernando, Manoharanehru Branavan, Wamadeva Balachandran, Aurore C. Poirier, Mohammed A. Rohaim, Muhammad Munir, Roberto M. La Ragione. An Artificial Intelligence-Assisted Portable Low-Cost Device for the Rapid Detection of SARS-CoV-2. Electronics. 2021; 10 (17):2065.
Chicago/Turabian StyleMukunthan Tharmakulasingam; Nouman S. Chaudhry; Anil Fernando; Manoharanehru Branavan; Wamadeva Balachandran; Aurore C. Poirier; Mohammed A. Rohaim; Muhammad Munir; Roberto M. La Ragione. 2021. "An Artificial Intelligence-Assisted Portable Low-Cost Device for the Rapid Detection of SARS-CoV-2." Electronics 10, no. 17: 2065.
Machinery with several rotating and stationary components tends to produce non-stationary and random vibration signatures due to the fluctuations in the input loads and process defects due to long hours of operation. Traditional heuristics methods are suitable for the detection of fault signatures, however, they become more complicated when the level of uncertainty or randomness exceeds beyond control. A novel methodology to identify these fault signatures using optimal filtering of vibration data is proposed to eliminate any false alarms and is expected to provide a higher probability of correct diagnosis. In this paper, a detailed pipeline of the algorithms are presented along with the results of the investigation that was carried out. These investigations are performed using open-source vibration data published by the NASA prognostics centre. The performance of these algorithms are evaluated based on the ground truth results published by NASA researchers. Based on the performance of these algorithms several parameters are fine-tuned to ensure generalisation and reliable performance.
Siu Ho; Harish Nedunuri; Wamadeva Balachandran; Jamil Kanfoud; Tat-Hean Gan. Monitoring of Industrial Machine Using a Novel Blind Feature Extraction Approach. Applied Sciences 2021, 11, 5792 .
AMA StyleSiu Ho, Harish Nedunuri, Wamadeva Balachandran, Jamil Kanfoud, Tat-Hean Gan. Monitoring of Industrial Machine Using a Novel Blind Feature Extraction Approach. Applied Sciences. 2021; 11 (13):5792.
Chicago/Turabian StyleSiu Ho; Harish Nedunuri; Wamadeva Balachandran; Jamil Kanfoud; Tat-Hean Gan. 2021. "Monitoring of Industrial Machine Using a Novel Blind Feature Extraction Approach." Applied Sciences 11, no. 13: 5792.
Sheet piles are significantly more prone to advanced corrosion rates due to accelerated low water corrosion. Current inspection and assessment techniques are costly, time-consuming and labour-intensive. Guided wave testing (GWT) has gained increased attention due to its capability of screening long distances; however, it has not been used previously to inspect the active zone in steel sheet piles. This paper focuses on the numerical modelling of wave propagation and defect detection in U-shaped piles to demonstrate the capabilities of GWT for the inspection of non-accessible areas of steel sheet piles. Two shear transducer arrays were designed, bearing high
Anuj Dhutti; Anurag Dhutti; Sergio Malo; Hugo Marques; Wamadeva Balachandran; Tat-Hean Gan. Numerical Modelling of Ultrasonic Guided Wave Propagation and Defect Detection in Offshore Steel Sheet Piles. Applied Sciences 2021, 11, 4076 .
AMA StyleAnuj Dhutti, Anurag Dhutti, Sergio Malo, Hugo Marques, Wamadeva Balachandran, Tat-Hean Gan. Numerical Modelling of Ultrasonic Guided Wave Propagation and Defect Detection in Offshore Steel Sheet Piles. Applied Sciences. 2021; 11 (9):4076.
Chicago/Turabian StyleAnuj Dhutti; Anurag Dhutti; Sergio Malo; Hugo Marques; Wamadeva Balachandran; Tat-Hean Gan. 2021. "Numerical Modelling of Ultrasonic Guided Wave Propagation and Defect Detection in Offshore Steel Sheet Piles." Applied Sciences 11, no. 9: 4076.
The expansion of applications involving hydrofluorocarbons has generated a demand for devices capable of measuring the electrical volume resistivity of such liquids across diverse operating conditions. The narrow operating range of commercial offerings, particularly in regard to pressure, compels researchers to develop custom cells for the desired test conditions. A review of resistivity cell designs developed over the past three decades is presented. Academic studies in the past have focussed on the development of cells for the purpose of testing the resistivity of refrigerants in liquid phase under high pressures. The fundamental principles underlying resistivity measurement are discussed while emphasis is placed on practical aspects of cell design. The review addresses facets including contemporary standards, limitations and constructional details of academic and commercial cells. It should serve as a guide for future researchers attempting to develop custom resistivity cells for dielectric liquids.
Hussein Ahmad; Wamadeva Balachandran; Nadarajah Manivannan. Measurement of electrical resistivity of hydrofluorocarbons – A review. Journal of Electrostatics 2021, 109, 103546 .
AMA StyleHussein Ahmad, Wamadeva Balachandran, Nadarajah Manivannan. Measurement of electrical resistivity of hydrofluorocarbons – A review. Journal of Electrostatics. 2021; 109 ():103546.
Chicago/Turabian StyleHussein Ahmad; Wamadeva Balachandran; Nadarajah Manivannan. 2021. "Measurement of electrical resistivity of hydrofluorocarbons – A review." Journal of Electrostatics 109, no. : 103546.
Until vaccines and effective therapeutics become available, the practical solution to transit safely out of the current coronavirus disease 19 (CoVID-19) lockdown may include the implementation of an effective testing, tracing and tracking system. However, this requires a reliable and clinically validated diagnostic platform for the sensitive and specific identification of SARS-CoV-2. Here, we report on the development of a de novo, high-resolution and comparative genomics guided reverse-transcribed loop-mediated isothermal amplification (LAMP) assay. To further enhance the assay performance and to remove any subjectivity associated with operator interpretation of results, we engineered a novel hand-held smart diagnostic device. The robust diagnostic device was further furnished with automated image acquisition and processing algorithms and the collated data was processed through artificial intelligence (AI) pipelines to further reduce the assay run time and the subjectivity of the colorimetric LAMP detection. This advanced AI algorithm-implemented LAMP (ai-LAMP) assay, targeting the RNA-dependent RNA polymerase gene, showed high analytical sensitivity and specificity for SARS-CoV-2. A total of ~200 coronavirus disease (CoVID-19)-suspected NHS patient samples were tested using the platform and it was shown to be reliable, highly specific and significantly more sensitive than the current gold standard qRT-PCR. Therefore, this system could provide an efficient and cost-effective platform to detect SARS-CoV-2 in resource-limited laboratories.
Mohammed Rohaim; Emily Clayton; Irem Sahin; Julianne Vilela; Manar Khalifa; Mohammad Al-Natour; Mahmoud Bayoumi; Aurore Poirier; Manoharanehru Branavan; Mukunthan Tharmakulasingam; Nouman Chaudhry; Ravinder Sodi; Amy Brown; Peter Burkhart; Wendy Hacking; Judy Botham; Joe Boyce; Hayley Wilkinson; Craig Williams; Jayde Whittingham-Dowd; Elisabeth Shaw; Matt Hodges; Lisa Butler; Michelle Bates; Roberto La Ragione; Wamadeva Balachandran; Anil Fernando; Muhammad Munir. Artificial Intelligence-Assisted Loop Mediated Isothermal Amplification (ai-LAMP) for Rapid Detection of SARS-CoV-2. Viruses 2020, 12, 972 .
AMA StyleMohammed Rohaim, Emily Clayton, Irem Sahin, Julianne Vilela, Manar Khalifa, Mohammad Al-Natour, Mahmoud Bayoumi, Aurore Poirier, Manoharanehru Branavan, Mukunthan Tharmakulasingam, Nouman Chaudhry, Ravinder Sodi, Amy Brown, Peter Burkhart, Wendy Hacking, Judy Botham, Joe Boyce, Hayley Wilkinson, Craig Williams, Jayde Whittingham-Dowd, Elisabeth Shaw, Matt Hodges, Lisa Butler, Michelle Bates, Roberto La Ragione, Wamadeva Balachandran, Anil Fernando, Muhammad Munir. Artificial Intelligence-Assisted Loop Mediated Isothermal Amplification (ai-LAMP) for Rapid Detection of SARS-CoV-2. Viruses. 2020; 12 (9):972.
Chicago/Turabian StyleMohammed Rohaim; Emily Clayton; Irem Sahin; Julianne Vilela; Manar Khalifa; Mohammad Al-Natour; Mahmoud Bayoumi; Aurore Poirier; Manoharanehru Branavan; Mukunthan Tharmakulasingam; Nouman Chaudhry; Ravinder Sodi; Amy Brown; Peter Burkhart; Wendy Hacking; Judy Botham; Joe Boyce; Hayley Wilkinson; Craig Williams; Jayde Whittingham-Dowd; Elisabeth Shaw; Matt Hodges; Lisa Butler; Michelle Bates; Roberto La Ragione; Wamadeva Balachandran; Anil Fernando; Muhammad Munir. 2020. "Artificial Intelligence-Assisted Loop Mediated Isothermal Amplification (ai-LAMP) for Rapid Detection of SARS-CoV-2." Viruses 12, no. 9: 972.
Until vaccines and effective therapeutics become available, the practical way to transit safely out of the current lockdown may include the implementation of an effective testing, tracing and tracking system. However, this requires a reliable and clinically validated diagnostic platform for the sensitive and specific identification of SARS-CoV-2. Here, we report on the development of a de novo, high-resolution and comparative genomics guided reverse-transcribed loop-mediated isothermal amplification (LAMP) assay. To further enhance the assay performance and to remove any subjectivity associated with operator interpretation of result, we engineered a novel hand-held smart diagnostic device. The robust diagnostic device was further furnished with automated image acquisition and processing algorithms, and the collated data was processed through artificial intelligence (AI) pipelines to further reduce the assay run time and the subjectivity of the colorimetric LAMP detection. This advanced AI algorithm-implemented LAMP (ai-LAMP) assay, targeting the RNA-dependent RNA polymerase gene, showed high analytical sensitivity and specificity for SARS-CoV-2. A total of ∼200 coronavirus disease (CoVID-19)-suspected patient samples were tested using the platform and it was shown to be reliable, highly specific and significantly more sensitive than the current gold standard qRT-PCR. The system could provide an efficient and cost-effective platform to detect SARS-CoV-2 in resource-limited laboratories.
Mohammed A Rohaim; Emily Clayton; Irem Sahin; Julianne Vilela; Manar E Khalifa; Mohammed Q Al-Natour; Mahmoud Bayoumi; Aurore Poirier; Manoharanehru Branavan; Mukunthan Tharmakulasingam; Nouman S Chaudhry; Ravinder Sodi; Amy Brown; Peter Burkhart; Wendy Hacking; Judy Botham; Joe Boyce; Hayley Wilkinson; Craig Williams; Michelle Bates; Roberto La Ragione; Wamadeva Balachandran; Anil Fernando; Muhammad Munir. Artificial Intelligence-Assisted Loop Mediated Isothermal Amplification (ai-LAMP) for Rapid and Reliable Detection of SARS-CoV-2. 2020, 1 .
AMA StyleMohammed A Rohaim, Emily Clayton, Irem Sahin, Julianne Vilela, Manar E Khalifa, Mohammed Q Al-Natour, Mahmoud Bayoumi, Aurore Poirier, Manoharanehru Branavan, Mukunthan Tharmakulasingam, Nouman S Chaudhry, Ravinder Sodi, Amy Brown, Peter Burkhart, Wendy Hacking, Judy Botham, Joe Boyce, Hayley Wilkinson, Craig Williams, Michelle Bates, Roberto La Ragione, Wamadeva Balachandran, Anil Fernando, Muhammad Munir. Artificial Intelligence-Assisted Loop Mediated Isothermal Amplification (ai-LAMP) for Rapid and Reliable Detection of SARS-CoV-2. . 2020; ():1.
Chicago/Turabian StyleMohammed A Rohaim; Emily Clayton; Irem Sahin; Julianne Vilela; Manar E Khalifa; Mohammed Q Al-Natour; Mahmoud Bayoumi; Aurore Poirier; Manoharanehru Branavan; Mukunthan Tharmakulasingam; Nouman S Chaudhry; Ravinder Sodi; Amy Brown; Peter Burkhart; Wendy Hacking; Judy Botham; Joe Boyce; Hayley Wilkinson; Craig Williams; Michelle Bates; Roberto La Ragione; Wamadeva Balachandran; Anil Fernando; Muhammad Munir. 2020. "Artificial Intelligence-Assisted Loop Mediated Isothermal Amplification (ai-LAMP) for Rapid and Reliable Detection of SARS-CoV-2." , no. : 1.
High-temperature (HT) ultrasonic transducers are of increasing interest for structural health monitoring (SHM) of structures operating in harsh environments. This article focuses on the development of an HT piezoelectric wafer active sensor (HT-PWAS) for SHM of HT pipelines using ultrasonic guided waves. The PWAS was fabricated using Y-cut gallium phosphate (GaPO4) to produce a torsional guided wave mode on pipes operating at temperatures up to 600 °C. A number of confidence-building tests on the PWAS were carried out. HT electromechanical impedance (EMI) spectroscopy was performed to characterise piezoelectric properties at elevated temperatures and over long periods of time (>1000 h). Laser Doppler vibrometry (LDV) was used to verify the modes of vibration. A finite element model of GaPO4 PWAS was developed to model the electromechanical behaviour of the PWAS and the effect of increasing temperatures, and it was validated using EMI and LDV experimental data. This study demonstrates the application of GaPO4 for guided-wave SHM of pipelines and presents a model that can be used to evaluate different transducer designs for HT applications.
Anurag Dhutti; Saiful Asmin Tumin; Wamadeva Balachandran; Jamil Kanfoud; Tat-Hean Gan. Development of Ultrasonic Guided Wave Transducer for Monitoring of High Temperature Pipelines. Sensors 2019, 19, 5443 .
AMA StyleAnurag Dhutti, Saiful Asmin Tumin, Wamadeva Balachandran, Jamil Kanfoud, Tat-Hean Gan. Development of Ultrasonic Guided Wave Transducer for Monitoring of High Temperature Pipelines. Sensors. 2019; 19 (24):5443.
Chicago/Turabian StyleAnurag Dhutti; Saiful Asmin Tumin; Wamadeva Balachandran; Jamil Kanfoud; Tat-Hean Gan. 2019. "Development of Ultrasonic Guided Wave Transducer for Monitoring of High Temperature Pipelines." Sensors 19, no. 24: 5443.
Continuous and reliable measurements of core body temperature (CBT) are vital for studies on human thermoregulation. Because tympanic membrane directly reflects the temperature of the carotid artery, it is an accurate and non-invasive method to record CBT. However, commercial tympanic thermometers lack portability and continuous measurements. In this study, graphene inks were utilized to increase the accuracy of the temperature measurements from the ear by coating graphene platelets on the lens of an infrared thermopile sensor. The proposed ear-based device was designed by investigating ear canal geometry and developed with 3D printing technology using the Computer-Aided Design (CAD) Software, SolidWorks 2016. It employs an Arduino Pro Mini and a Bluetooth module. The proposed system runs with a 3.7 V, 850 mAh rechargeable lithium-polymer battery that allows long-term, continuous monitoring. Raw data are continuously and wirelessly plotted on a mobile phone app. The test was performed on 10 subjects under resting and exercising in a total period of 25 min. Achieved results were compared with the commercially available Braun Thermoscan, Original Thermopile, and Cosinuss One ear thermometers. It is also comprehended that such system will be useful in personalized medicine as wearable in-ear device with wireless connectivity.
Jorge S. Chaglla E.; Numan Celik; Wamadeva Balachandran. Measurement of Core Body Temperature Using Graphene-Inked Infrared Thermopile Sensor. Sensors 2018, 18, 3315 .
AMA StyleJorge S. Chaglla E., Numan Celik, Wamadeva Balachandran. Measurement of Core Body Temperature Using Graphene-Inked Infrared Thermopile Sensor. Sensors. 2018; 18 (10):3315.
Chicago/Turabian StyleJorge S. Chaglla E.; Numan Celik; Wamadeva Balachandran. 2018. "Measurement of Core Body Temperature Using Graphene-Inked Infrared Thermopile Sensor." Sensors 18, no. 10: 3315.
Gallium phosphate single crystal has a very stable thermal response, ideal for high temperature applications such as transducers for in-service monitoring of HT infrastructure in Power and Oil & Gas industries. Broadband transducers are designed to resonate with a specific mode of vibration within a frequency range of interest. This desired frequency response depends on how the transducer is mounted on the structure and the target defect sensitivity. Electrode configurations are defined to achieve the transducer design. This study investigates the parallel and wrap-around electrode configurations on the transducer response. An electro-mechanical finite element model was developed to analyse the transducer response and predicted a disparity in the modes of vibration between the two configurations within the same frequency range. This model was experimentally validated by measuring the displacement patterns using 3D Laser Doppler Vibrometry.
Anurag Dhutti; Tat-Hean Gan; Abbas Mohimi; Wamadeva Balachandran; Jamil Kanfoud. Effect of Electrode Configuration on High Temperature Thickness Shear Gallium Phosphate Transducer. Proceedings 2017, 1, 381 .
AMA StyleAnurag Dhutti, Tat-Hean Gan, Abbas Mohimi, Wamadeva Balachandran, Jamil Kanfoud. Effect of Electrode Configuration on High Temperature Thickness Shear Gallium Phosphate Transducer. Proceedings. 2017; 1 (4):381.
Chicago/Turabian StyleAnurag Dhutti; Tat-Hean Gan; Abbas Mohimi; Wamadeva Balachandran; Jamil Kanfoud. 2017. "Effect of Electrode Configuration on High Temperature Thickness Shear Gallium Phosphate Transducer." Proceedings 1, no. 4: 381.
Surface-enhanced Raman spectroscopy (SERS) substrates manufactured using complex nano-patterning techniques have become the norm. However, their cost of manufacture makes them unaffordable to incorporate into most biosensors. The technique shown in this paper is low-cost, reliable and highly sensitive. Chemical etching of solid Ag metal was used to produce simple, yet robust SERS substrates with broadband characteristics. Etching with ammonium hydroxide (NH4OH) and nitric acid (HNO3) helped obtain roughened Ag SERS substrates. Scanning electron microscopy (SEM) and interferometry were used to visualize and quantify surface roughness. Flattened Ag wires had inherent, but non-uniform roughness having peaks and valleys in the microscale. NH4OH treatment removed dirt and smoothened the surface, while HNO3 treatment produced a flake-like morphology with visibly more surface roughness features on Ag metal. SERS efficacy was tested using 4-methylbenzenethiol (MBT). The best SERS enhancement for 1 mM MBT was observed for Ag metal etched for 30 s in NH4OH followed by 10 s in HNO3. Further, MBT could be quantified with detection limits of 1 pM and 100 µM, respectively, using 514 nm and 1064 nm Raman spectrometers. Thus, a rapid and less energy intensive method for producing solid Ag SERS substrate and its efficacy in analyte sensing was demonstrated.
Shavini Wijesuriya; Krishna Burugapalli; Ruth Mackay; Godwin Chukwuebuka Ajaezi; Wamadeva Balachandran. Chemically Roughened Solid Silver: A Simple, Robust and Broadband SERS Substrate. Sensors 2016, 16, 1742 .
AMA StyleShavini Wijesuriya, Krishna Burugapalli, Ruth Mackay, Godwin Chukwuebuka Ajaezi, Wamadeva Balachandran. Chemically Roughened Solid Silver: A Simple, Robust and Broadband SERS Substrate. Sensors. 2016; 16 (10):1742.
Chicago/Turabian StyleShavini Wijesuriya; Krishna Burugapalli; Ruth Mackay; Godwin Chukwuebuka Ajaezi; Wamadeva Balachandran. 2016. "Chemically Roughened Solid Silver: A Simple, Robust and Broadband SERS Substrate." Sensors 16, no. 10: 1742.
The unique parameters of graphene (GN)—notably its considerable electron mobility, high surface area, and electrical conductivity—are bringing extensive attention into the wearable technologies. This work presents a novel graphene-based electrode for acquisition of electrocardiogram (ECG). The proposed electrode was fabricated by coating GN on top of a metallic layer of a Ag/AgCl electrode using a chemical vapour deposition (CVD) technique. To investigate the performance of the fabricated GN-based electrode, two types of electrodes were fabricated with different sizes to conduct the signal qualities and the skin-electrode contact impedance measurements. Performances of the GN-enabled electrodes were compared to the conventional Ag/AgCl electrodes in terms of ECG signal quality, skin–electrode contact impedance, signal-to-noise ratio (SNR), and response time. Experimental results showed the proposed GN-based electrodes produced better ECG signals, higher SNR (improved by 8%), and lower contact impedance (improved by 78%) values than conventional ECG electrodes.
Numan Celik; Nadarajah Manivannan; Andrew Strudwick; Wamadeva Balachandran. Graphene-Enabled Electrodes for Electrocardiogram Monitoring. Nanomaterials 2016, 6, 156 .
AMA StyleNuman Celik, Nadarajah Manivannan, Andrew Strudwick, Wamadeva Balachandran. Graphene-Enabled Electrodes for Electrocardiogram Monitoring. Nanomaterials. 2016; 6 (9):156.
Chicago/Turabian StyleNuman Celik; Nadarajah Manivannan; Andrew Strudwick; Wamadeva Balachandran. 2016. "Graphene-Enabled Electrodes for Electrocardiogram Monitoring." Nanomaterials 6, no. 9: 156.
Guided Wave Testing (GWT) using novel Electromagnetic Acoustic Transducers (EMATs) is proposed for the inspection of large structures operating at high temperatures. To date, high temperature EMATs have been developed only for thickness measurements and they are not suitable for GWT. A pair of water-cooled EMATs capable of exciting and receiving Shear Horizontal (SH0) waves for GWT with optimal high temperature properties (up to 500 °C) has been developed. Thermal and Computational Fluid Dynamic (CFD) simulations of the EMAT design have been performed and experimentally validated. The optimal thermal EMAT design, material selection and operating conditions were calculated. The EMAT was successfully tested regarding its thermal and GWT performance from ambient temperature to 500 °C.
Maria Kogia; Tat-Hean Gan; Wamadeva Balachandran; Makis Livadas; Vassilios Kappatos; Istvan Szabo; Abbas Mohimi; Andrew Round. High Temperature Shear Horizontal Electromagnetic Acoustic Transducer for Guided Wave Inspection. Sensors 2016, 16, 582 .
AMA StyleMaria Kogia, Tat-Hean Gan, Wamadeva Balachandran, Makis Livadas, Vassilios Kappatos, Istvan Szabo, Abbas Mohimi, Andrew Round. High Temperature Shear Horizontal Electromagnetic Acoustic Transducer for Guided Wave Inspection. Sensors. 2016; 16 (4):582.
Chicago/Turabian StyleMaria Kogia; Tat-Hean Gan; Wamadeva Balachandran; Makis Livadas; Vassilios Kappatos; Istvan Szabo; Abbas Mohimi; Andrew Round. 2016. "High Temperature Shear Horizontal Electromagnetic Acoustic Transducer for Guided Wave Inspection." Sensors 16, no. 4: 582.
Concentrated Solar Plants (CSPs) are used in solar thermal industry for collecting and converting sunlight into electricity. Parabolic trough CSPs are the most widely used type of CSP and an absorber tube is an essential part of them. The hostile operating environment of the absorber tubes, such as high temperatures (400–550 °C), contraction/expansion, and vibrations, may lead them to suffer from creep, thermo-mechanical fatigue, and hot corrosion. Hence, their condition monitoring is of crucial importance and a very challenging task as well. Electromagnetic Acoustic Transducers (EMATs) are a promising, non-contact technology of transducers that has the potential to be used for the inspection of large structures at high temperatures by exciting Guided Waves. In this paper, a study regarding the potential use of EMATs in this application and their performance at high temperature is presented. A Periodic Permanent Magnet (PPM) EMAT with a racetrack coil, designed to excite Shear Horizontal waves (SH0), has been theoretically and experimentally evaluated at both room and high temperatures.
Maria Kogia; Liang Cheng; Abbas Mohimi; Vassilios Kappatos; Tat-Hean Gan; Wamadeva Balachandran; Cem Selcuk. Electromagnetic Acoustic Transducers Applied to High Temperature Plates for Potential Use in the Solar Thermal Industry. Applied Sciences 2015, 5, 1715 -1734.
AMA StyleMaria Kogia, Liang Cheng, Abbas Mohimi, Vassilios Kappatos, Tat-Hean Gan, Wamadeva Balachandran, Cem Selcuk. Electromagnetic Acoustic Transducers Applied to High Temperature Plates for Potential Use in the Solar Thermal Industry. Applied Sciences. 2015; 5 (4):1715-1734.
Chicago/Turabian StyleMaria Kogia; Liang Cheng; Abbas Mohimi; Vassilios Kappatos; Tat-Hean Gan; Wamadeva Balachandran; Cem Selcuk. 2015. "Electromagnetic Acoustic Transducers Applied to High Temperature Plates for Potential Use in the Solar Thermal Industry." Applied Sciences 5, no. 4: 1715-1734.
Abatement of NOx and particulate matters (PM) of marine diesel exhaust gas using microwave (MW) non-thermal plasma is presented in this paper. NOx mainly consist of NO and less concentration of NO2 in a typical two stoke marine diesel engine and microwave plasma generation can completely remove NO. MW was generated using two 2kW microwave sources and a saw tooth passive electrode. Passive electrode was used to generate high electric field region within microwave environment where high energetic electrons (1-3eV) are produced for the generation of non-thermal plasma (NTP). 2kW gen-set diesel exhaust gas was used to test our pilot-scale MW plasma reactor. The experimental results show that almost 100% removal of NO is possible for the exhaust gas flow rate of 60l/s. It was also shown that MW can significantly remove soot particles (PM, 10nm to 365nm) entrained in the exhaust gas of 200kW marine diesel engine with 40% engine load and gas flow rate of 130l/s. MW without generating plasma showed reduction up to 50% reduction of PM and with the plasma up to 90% reduction. The major challenge in these experiments was that igniting the desired plasma and sustaining it with passive electrodes for longer period (10s of minutes) as it required fine tuning of electrode position, which was influenced by many factors such as gas flow rate, geometry of reactor and MW power.
W Balachandran; P Finst; N Manivannan; R Beleca; M Abbod. Reduction of NOx and PM in marine diesel engine exhaust gas using microwave plasma. Journal of Physics: Conference Series 2015, 646, 012053 .
AMA StyleW Balachandran, P Finst, N Manivannan, R Beleca, M Abbod. Reduction of NOx and PM in marine diesel engine exhaust gas using microwave plasma. Journal of Physics: Conference Series. 2015; 646 (1):012053.
Chicago/Turabian StyleW Balachandran; P Finst; N Manivannan; R Beleca; M Abbod. 2015. "Reduction of NOx and PM in marine diesel engine exhaust gas using microwave plasma." Journal of Physics: Conference Series 646, no. 1: 012053.
A Si3N4 membrane with a thin Cr coating is proposed and demonstrated as an electron beam exit window. On average, 85% electron power transmission efficiency was achieved with a 1 μm thick Si3N4 membrane coated with 1 μm thick Cr and the membrane sustained a beam current of up to 3 mA at 60 keV electron energy for the continuous operation of 3 min. However, for an uncoated membrane of same thickness, the average electron power transmission efficiency was 71% and the maximum beam current sustained was 800 μA. It was also shown that a one micron thick Si3N4 square membrane window of 10 mm × 10 mm could withstand a differential pressure of 1.3 bars.
N. Manivannan; W. Balachandran; C. Ribton; R. Beleca; M. Abbod; M. Cox; P. Anastasia. Chromium coated silicon nitride electron beam exit window. Vacuum 2014, 113, 19 -23.
AMA StyleN. Manivannan, W. Balachandran, C. Ribton, R. Beleca, M. Abbod, M. Cox, P. Anastasia. Chromium coated silicon nitride electron beam exit window. Vacuum. 2014; 113 ():19-23.
Chicago/Turabian StyleN. Manivannan; W. Balachandran; C. Ribton; R. Beleca; M. Abbod; M. Cox; P. Anastasia. 2014. "Chromium coated silicon nitride electron beam exit window." Vacuum 113, no. : 19-23.
Abbas Mohimi; Tat-Hean Gan; Wamadeva Balachandran. Development of high temperature ultrasonic guided wave transducer for continuous in service monitoring of steam lines using non-stoichiometric lithium niobate piezoelectric ceramic. Sensors and Actuators A: Physical 2014, 216, 432 -442.
AMA StyleAbbas Mohimi, Tat-Hean Gan, Wamadeva Balachandran. Development of high temperature ultrasonic guided wave transducer for continuous in service monitoring of steam lines using non-stoichiometric lithium niobate piezoelectric ceramic. Sensors and Actuators A: Physical. 2014; 216 ():432-442.
Chicago/Turabian StyleAbbas Mohimi; Tat-Hean Gan; Wamadeva Balachandran. 2014. "Development of high temperature ultrasonic guided wave transducer for continuous in service monitoring of steam lines using non-stoichiometric lithium niobate piezoelectric ceramic." Sensors and Actuators A: Physical 216, no. : 432-442.
In this paper shear type lithium niobate has been studied. The impedance-frequency characteristics were measured at high temperatures. This was carried out by placing the samples inside a furnace and performing in-situ impedance measurements at up to 600°C. The characteristic frequencies, capacitance, density and dimensions of samples were used to calculate the dielectric, elastic and piezoelectric coefficients. Prototype transducers were built using shear type lithium niobate crystals. The initial ultrasonic experiments show that it can be used at temperatures up to 450°C to transmit and receive guided wave signals at 70 kHz. This will enable design and manufacture of high temperature transducers for continuous guided wave monitoring of power plants.
Abbas Mohimi; Philip Richardson; Phil Catton; Tat Hean Gan; Wamadeva Balachandran; Cem Selcuk. High Temperature Dielectric, Elastic and Piezoelectric Coefficients of Shear Type Lithium Niobate Crystals. Key Engineering Materials 2013, 543, 117 -120.
AMA StyleAbbas Mohimi, Philip Richardson, Phil Catton, Tat Hean Gan, Wamadeva Balachandran, Cem Selcuk. High Temperature Dielectric, Elastic and Piezoelectric Coefficients of Shear Type Lithium Niobate Crystals. Key Engineering Materials. 2013; 543 ():117-120.
Chicago/Turabian StyleAbbas Mohimi; Philip Richardson; Phil Catton; Tat Hean Gan; Wamadeva Balachandran; Cem Selcuk. 2013. "High Temperature Dielectric, Elastic and Piezoelectric Coefficients of Shear Type Lithium Niobate Crystals." Key Engineering Materials 543, no. : 117-120.
This paper presents a holistic methodology for the design of medical device software, which encompasses of a new way of eliciting requirements, system design process, security design guideline, cloud architecture design, combinatorial testing process and agile project management. The paper uses point of care diagnostics as a case study where the software and hardware must be robust, reliable to provide accurate diagnosis of diseases. As software and software intensive systems are becoming increasingly complex, the impact of failures can lead to significant property damage, or damage to the environment. Within the medical diagnostic device software domain such failures can result in misdiagnosis leading to clinical complications and in some cases death. Software faults can arise due to the interaction among the software, the hardware, third party software and the operating environment. Unanticipated environmental changes and latent coding errors lead to operation faults despite of the fact that usually a significant effort has been expended in the design, verification and validation of the software system. It is becoming increasingly more apparent that one needs to adopt different approaches, which will guarantee that a complex software system meets all safety, security, and reliability requirements, in addition to complying with standards such as IEC 62304. There are many initiatives taken to develop safety and security critical systems, at different development phases and in different contexts, ranging from infrastructure design to device design. Different approaches are implemented to design error free software for safety critical systems. By adopting the strategies and processes presented in this paper one can overcome the challenges in developing error free software for medical devices (or safety critical systems).
Sivanesan Tulasidas; Ruth Mackay; Pascal Craw; Chris Hudson; Voula Gkatzidou; Wamadeva Balachandran. Process of Designing Robust, Dependable, Safe and Secure Software for Medical Devices: Point of Care Testing Device as a Case Study. Journal of Software Engineering and Applications 2013, 06, 1 -13.
AMA StyleSivanesan Tulasidas, Ruth Mackay, Pascal Craw, Chris Hudson, Voula Gkatzidou, Wamadeva Balachandran. Process of Designing Robust, Dependable, Safe and Secure Software for Medical Devices: Point of Care Testing Device as a Case Study. Journal of Software Engineering and Applications. 2013; 06 (09):1-13.
Chicago/Turabian StyleSivanesan Tulasidas; Ruth Mackay; Pascal Craw; Chris Hudson; Voula Gkatzidou; Wamadeva Balachandran. 2013. "Process of Designing Robust, Dependable, Safe and Secure Software for Medical Devices: Point of Care Testing Device as a Case Study." Journal of Software Engineering and Applications 06, no. 09: 1-13.
Electrostatic properties of formulation component materials and blends play an important role in dry powder inhalation (DPI) products. Valid measurement of charge distribution will therefore lead to better control of powder behavior in DPI manufacturing processes. Ultrafine powders are known to have bipolar charge, have nonspherical shapes, and tend to be highly cohesive. Real-time noninvasive techniques need to be developed to obtain a precise and accurate measurement of electrically charged powders, as they aerosolize from a DPI product. How this measure relates to materials behavior throughout the various steps of a manufacturing process, e.g., from drug micronization and blending with lactose to filling dose units, also needs to be addressed. A novel noninvasive technique, which employs the phase Doppler anemometry (PDA) system for simultaneous measurement of size and charge of pharmaceutical powders, is currently being considered. Previous research demonstrated the advantages of this technique in measuring the bipolar charge distribution on a population of liquid aerosols. These findings led to significant improvements in understanding the performance of inhaler formulations, manufacturing processes, and development of new devices for inhaled drug delivery. This paper presents an investigation of electrostatic properties of lactose materials (typically used as a DPI excipient) using the PDA system. PDA calibration was checked using dry polystyrene microspheres, followed by an investigation of different grades of lactose. The PDA technique was used to track the motion of charged particles in the presence of an electric field. The magnitude, as well as the polarity of the particle charge, can be obtained by solving the equation of particle motion combined with the simultaneous measurement of its size and velocity. Results show the capability of the technique to allow real-time charge distribution and size measurement in the control of dry powder attributes that are critical to a better understanding of the manufacturing design space.
Radu Beleca; Maysam Abbod; Wamadeva Balachandran; Paul R. Miller. Investigation of Electrostatic Properties of Pharmaceutical Powders Using Phase Doppler Anemometry. IEEE Transactions on Industry Applications 2010, 46, 1181 -1187.
AMA StyleRadu Beleca, Maysam Abbod, Wamadeva Balachandran, Paul R. Miller. Investigation of Electrostatic Properties of Pharmaceutical Powders Using Phase Doppler Anemometry. IEEE Transactions on Industry Applications. 2010; 46 (3):1181-1187.
Chicago/Turabian StyleRadu Beleca; Maysam Abbod; Wamadeva Balachandran; Paul R. Miller. 2010. "Investigation of Electrostatic Properties of Pharmaceutical Powders Using Phase Doppler Anemometry." IEEE Transactions on Industry Applications 46, no. 3: 1181-1187.
Experiments on the removal of smoke particles by charged droplets were carried out. The droplets were charged inductively during their spraying by a rotary atomizer. The electrical charging of droplets significantly increases the efficiency of removal of smoke particles from air as compared to the uncharged aerosol.
W. Balachandran; A. Krupa; W. Machowski; A. Jaworek. Smoke precipitation by charged water aerosol. Journal of Electrostatics 2001, 51-52, 193 -199.
AMA StyleW. Balachandran, A. Krupa, W. Machowski, A. Jaworek. Smoke precipitation by charged water aerosol. Journal of Electrostatics. 2001; 51-52 ():193-199.
Chicago/Turabian StyleW. Balachandran; A. Krupa; W. Machowski; A. Jaworek. 2001. "Smoke precipitation by charged water aerosol." Journal of Electrostatics 51-52, no. : 193-199.