High Performance Multicell Series Inverter-Fed Induction Motor Drive

This document is the Accepted Manuscript version of the following article: M. Khodja, D. Rahiel, M. B. Benabdallah, H. Merabet Boulouiha, A. Allali, A. Chaker, and M. Denai, ‘High-performance multicell series inverter-fed induction motor drive’, Electrical Engineering, Vol. 99 (3): 1121-1137, September 2017. The final publication is available at Springer via DOI: https://doi.org/10.1007/s00202-016-0472-4.The multilevel voltage-source inverter (VSI) topology of the series multicell converter developed in recent years has led to improved converter performance in terms of power density and efficiency. This converter reduces the voltage constraints between all cells, which results in a lower transmission losses, high switching frequencies and the improvement of the output voltage waveforms. This paper proposes an improved topology of the series multicell inverter which minimizes harmonics, reduces torque ripples and losses in a variable-speed induction motor drive. The flying capacitor multilevel inverter topology based on the classical and modified phase shift pulse width modulation (PSPWM, MPSPWM) techniques are applied in this paper to minimize harmonic distortion at the inverter output. Simulation results are presented for a 2-kW induction motor drive and the results obtained demonstrate reduced harmonics, improved transient responses and reference tracking performance of the voltage in the induction motor and consequently reduced torque ripplesPeer reviewe

Efficacy of transarterial chemoembolization on lesion reduction in colorectal liver metastases

Following failure of systemic chemotherapy, transarterial chemoembolization (TACE) is an available method to control unresectable liver metastases from colorectal carcinoma (CRC). The aim of present study was to evaluate the efficacy of chemoembolization for inoperable metastatic liver lesions from CRC. Forty-five CRC patients with liver metastases resistant to systemic chemotherapy were enrolled in our study. For each patient, three session of TACE were conducted with 45 days interval. A combination of mitomycin, doxorubicin, and lipiodol were used for TACE. A tri-phasic computed tomography scan and biochemical laboratory tests were performed for all patients at baseline and 30 days after each TACE. Image analysis included measurement of lesion diameters as well as contrast enhancement. Eleven patients deceased before completing three session and the final analyses were performed on the remaining 34 patients. Evaluation of a total 93 lesions in all patients after chemoembolization sessions revealed a 25.88 reduction in anteroposterior (AP) diameter, 33.92 transverse (T) diameter, and 42.22 in product of APxT diameter of lesions (P<0.001 for all instances). CT scan showed a total disappearance of 33 of lesions and evident reduction in contrast enhancement in 16 of them. There were no changes in contrast enhancement in 51 of lesions. Evaluation of single largest lesion in each patient revealed 57.32 reduction in AP diameter, 59.66 in T diameter, and 62.17 in product of APxT diameters (P<0.001 for all diameters). TACE offers a viable option for CRC patients with unresectable liver metastases by significantly reducing lesion size and contrast enhancement. © 2012 Tehran University of Medical Sciences. All rights reserved

Ultra-soft 100 nm Thick Zero Poisson’s Ratio Film with 60% Reversible Compressibility

About a 100 nm thick multilayer film of nanoparticle monolayers and polymer layers is shown to behave like cellular-foam with a modulus below 100 KPa. The 1.25 cm radius film adhered to a rigid surface can be compressed reversibly to 60% strain. The more than four orders of magnitude lower modulus compared to its constituents is explained by considering local bending in the (nano)cellular structure, similar to cork and wings of beetles. As the rigidity of the polymer backbone is increased in just four monolayers the modulus of the composite increases by over 70%. Electro-optical map of the strain distribution over the area of compression and increase in modulus with thickness indicates the films have zero Poisson’s ratio

Global investments in pandemic preparedness and COVID-19: development assistance and domestic spending on health between 1990 and 2026

Background The COVID-19 pandemic highlighted gaps in health surveillance systems, disease prevention, and treatment globally. Among the many factors that might have led to these gaps is the issue of the financing of national health systems, especially in low-income and middle-income countries (LMICs), as well as a robust global system for pandemic preparedness. We aimed to provide a comparative assessment of global health spending at the onset of the pandemic; characterise the amount of development assistance for pandemic preparedness and response disbursed in the first 2 years of the COVID-19 pandemic; and examine expectations for future health spending and put into context the expected need for investment in pandemic preparedness. Methods In this analysis of global health spending between 1990 and 2021, and prediction from 2021 to 2026, we estimated four sources of health spending: development assistance for health (DAH), government spending, out-of-pocket spending, and prepaid private spending across 204 countries and territories. We used the Organisation for Economic Co-operation and Development (OECD)'s Creditor Reporting System (CRS) and the WHO Global Health Expenditure Database (GHED) to estimate spending. We estimated development assistance for general health, COVID-19 response, and pandemic preparedness and response using a keyword search. Health spending estimates were combined with estimates of resources needed for pandemic prevention and preparedness to analyse future health spending patterns, relative to need. Findings In 2019, at the onset of the COVID-19 pandemic, US$9·2 trillion (95$7·3 trillion (95% UI 7·2–7·4) in 2019; 293·7 times the $24·8 billion (95$43·1 billion in development assistance was provided to maintain or improve health. The pandemic led to an unprecedented increase in development assistance targeted towards health; in 2020 and 2021, $1·8 billion in DAH contributions was provided towards pandemic preparedness in LMICs, and$37·8 billion was provided for the health-related COVID-19 response. Although the support for pandemic preparedness is 12·2% of the recommended target by the High-Level Independent Panel (HLIP), the support provided for the health-related COVID-19 response is 252·2% of the recommended target. Additionally, projected spending estimates suggest that between 2022 and 2026, governments in 17 (95% UI 11–21) of the 137 LMICs will observe an increase in national government health spending equivalent to an addition of 1% of GDP, as recommended by the HLIP. Interpretation There was an unprecedented scale-up in DAH in 2020 and 2021. We have a unique opportunity at this time to sustain funding for crucial global health functions, including pandemic preparedness. However, historical patterns of underfunding of pandemic preparedness suggest that deliberate effort must be made to ensure funding is maintained

SPARC 2022 book of abstracts

Welcome to the Book of Abstracts for the 2022 SPARC conference. Our conference is called “Moving Forwards” reflecting our re-emergence from the pandemic and our desire to reconnect our PGR community, in celebration of their research. PGRs have continued with their research endeavours despite many challenges, and their ongoing successes are underpinned by the support and guidance of dedicated supervisors and the Doctoral School Team. To recognise supervision excellence we will be awarding our annual Supervisor of the Year prizes, based on the wonderful nominations received from their PGR students.Once again, we have received a tremendous contribution from our postgraduate research community; with over 60 presenters, 12 Three-Minute Thesis finalists, and 20 poster presentations, the conference showcases our extraordinarily vibrant, inclusive, and resilient PGR community at Salford. This year there will be prizes to be won for ‘best in conference’ presentations, in addition to the winners from each parallel session. Audience members too could be in for a treat, with judges handing out spot prizes for the best questions asked, so don’t miss the opportunity to put your hand up. These abstracts provide a taster of the diverse and impactful research in progress and provide delegates with a reference point for networking and initiating critical debate. Take advantage of the hybrid format: in online sessions by posting a comment or by messaging an author to say “Hello”, or by initiating break time discussions about the amazing research you’ve seen if you are with us in person. Who knows what might result from your conversation? With such wide-ranging topics being showcased, we encourage you to take up this great opportunity to engage with researchers working in different subject areas from your own. As recent events have shown, researchers need to collaborate to meet global challenges. Interdisciplinary and international working is increasingly recognised and rewarded by all major research funders. We do hope, therefore, that you will take this opportunity to initiate interdisciplinary conversations with other researchers. A question or comment from a different perspective can shed new light on a project and could lead to exciting collaborations, and that is what SPARC is all about. SPARC is part of a programme of personal and professional development opportunities offered to all postgraduate researchers at Salford. More information about this programme is available on our website: Doctoral School | University of Salford. Registered Salford students can access full details on the Doctoral School hub: Doctoral School Hub - Home (sharepoint.com) You can follow us on Twitter @SalfordPGRs and please use the #SPARC2022 to share your conference experience.We particularly welcome taught students from our undergraduate and master’s programmes as audience members. We hope you enjoy the presentations on offer and that they inspire you to pursue your own research career. If you would like more information about studying for a PhD here at the University of Salford, your lecturers can advise, or you can contact the relevant PGR Support Officer; their details can be found at Doctoral School | University of Salford. We wish you a rich and rewarding conference experience

High efficiency single stage dual output smart battery charger: Marine application

This paper presents a single stage smart battery charger for marine applications. High energy efficiency is a unique advantage of the proposed charger. It has dual outputs; it can charge two batteries separately at the same time. The demonstrated topology has a fault tolerant (FT) capability in case of dual open switch faults. In addition it can be used in parallel mode to reduce the charge time significantly or in standalone mode to improve light load efficiency. A control technique and fault detection (FD) method is also developed for the proposed charger. To validate the theory, a 600 W, 24 VDC dual output battery charger with universal input 120/230 VAC is simulated in Matlab/Simulink under different load and input voltage conditions