A three-phase to single-phase matrix converter for high-frequency induction heating

The paper describes a new three-phase to single-phase matrix converter featuring unity input power factor, very low input total harmonic distortion, and soft-switching over the full power range, for high frequency induction heating applications. A variable output pulse density modulation scheme has been proposed for stable operation of the converter, with the notable feature of requiring no on-line calculations for the synthesis of three-phase input current system. Practical issues in realising the converter, viz. line frequency synchronisation and output current circulation, are described. Good agreement between simulation and experimental results confirm the benefits of the proposed converter

Nipah shell disorder, modes of infection, and virulence

The Nipah Virus (NiV) was first isolated during a 1998–9 outbreak in Malaysia. The outbreak initially infected farm pigs and then moved to humans from pigs with a case-fatality rate (CFR) of about 40%. After 2001, regular outbreaks occurred with higher CFRs (~71%, 2001–5, ~93%, 2008–12). The spread arose from drinking virus-laden palm date sap and human-to-human transmission. Intrinsic disorder analysis revealed strong correlation between the percentage of disorder in the N protein and CFR (Regression: r2 = 0.93, p < 0.01, ANOVA: p < 0.01). Distinct disorder and, therefore, genetic differences can be found in all three group of strains. The fact that the transmission modes of the Malaysia strain are different from those of the Bangladesh strains suggests that the correlations may also be linked to the modes of viral transmission. Analysis of the NiV and related viruses suggests links between modes of transmission and disorder of not just the N protein but, also, of M shell protein. The links among shell disorder, transmission modes, and virulence suggest mechanisms by which viruses are attenuated as they passed through different cell hosts from different animal species. These have implications for development of vaccines and epidemiological molecular analytical tools to contain outbreaks

Comparison of single-phase matrix converter and H-bridge converter for radio frequency induction heating

This paper compares the newly developed single-phase matrix converter and the more conventional H- bridge converter for radio frequency induction heating. Both the converters exhibit unity power factor, very low total harmonic distortion at the utility supply interface, good controllability under soft switching condition for a wide range of power, and high efficiencies, whilst still having simple structures. A novel switching control pattern has been proposed for the matrix converter in order to maintain the comparable performance to the H-bridge converter. Simulation and experimental results for both converters are presented. Comparisons between two converters have confirmed the excellent performance of the proposed matrix converter

Rigidity of the Outer Shell Predicted by a Protein Intrinsic Disorder Model Sheds Light on the COVID-19 (Wuhan-2019-nCoV) Infectivity

The world is currently witnessing an outbreak of a new coronavirus spreading quickly across China and affecting at least 24 other countries. With almost 65,000 infected, a worldwide death toll of at least 1370 (as of 14 February 2020), and with the potential to affect up to two-thirds of the world population, COVID-19 is considered by the World Health Organization (WHO) to be a global health emergency. The speed of spread and infectivity of COVID-19 (also known as Wuhan-2019-nCoV) are dramatically exceeding those of the Middle East respiratory syndrome coronavirus (MERS-CoV) and severe acute respiratory syndrome coronavirus (SARS-CoV). In fact, since September 2012, the WHO has been notified of 2494 laboratory-confirmed cases of infection with MERS-CoV, whereas the 2002–2003 epidemic of SARS affected 26 countries and resulted in more than 8000 cases. Therefore, although SARS, MERS, and COVID-19 are all the result of coronaviral infections, the causes of the coronaviruses differ dramatically in their transmissibility. It is likely that these differences in infectivity of coronaviruses can be attributed to the differences in the rigidity of their shells which can be evaluated using computational tools for predicting intrinsic disorder predisposition of the corresponding viral proteins

Computation of Multi-State Models using GAUSS, A Matrix Based Programming Language

In this paper we present a series of programs in GAUSS. Three areas of application are shown: (1) construction of a multi-state life table, (2) projection of a multi-state population, and (3) the calculation of variances and covariances for a projected population. Illustrative results are presented for marital status data by age for Canadian women in 1981. Program code and the appropriate data are provided so that the reader may reproduce our results and develop a working knowledge of multi-state analysis. The programs are readily applicable to data for other countries, and to multi-region as well as to marital status analysis

Prompt energization of relativistic and highly relativistic electrons during a substorm interval: Van Allen Probes observations

Abstract On 17 March 2013, a large magnetic storm significantly depleted the multi-MeV radiation belt. We present multi-instrument observations from the Van Allen Probes spacecraft Radiation Belt Storm Probe A and Radiation Belt Storm Probe B at ~6 Re in the midnight sector magnetosphere and from ground-based ionospheric sensors during a substorm dipolarization followed by rapid reenergization of multi-MeV electrons. A 50% increase in magnetic field magnitude occurred simultaneously with dramatic increases in 100 keV electron fluxes and a 100 times increase in VLF wave intensity. The 100 keV electrons and intense VLF waves provide a seed population and energy source for subsequent radiation belt enhancements. Highly relativistic (\u3e2 MeV) electron fluxes increased immediately at L* ~ 4.5 and 4.5 MeV flux increased \u3e90 times at L* = 4 over 5 h. Although plasmasphere expansion brings the enhanced radiation belt multi-MeV fluxes inside the plasmasphere several hours postsubstorm, we localize their prompt reenergization during the event to regions outside the plasmasphere. Key Points Substorm dynamics are important for highly relativistic electron energization Cold plasma preconditioning is significant for rapid relativistic energization Relativistic / highly relativistic electron energization can occur in \u3c 5 hrs

Optimisation of panel component regions subject to hot stamping constraints using a novel deep-learning-based platform

The latest hot stamping processes can enable efficient production of complex shaped panel components with high stiffness-to-weight ratios. However, structural redesign for these intricate processes can be challenging, because compared to cold forming, the non-isothermal and dynamic nature of these processes introduces complexity and unfamiliarity among industrial designers. In industrial practice, trial-and-error approaches are currently used to update non-feasible designs where complicated forming simulations are needed each time a design change is made. A superior approach to structural redesign for hot stamping processes is demonstrated in this paper which applies a novel deep-learning-based optimisation platform. The platform consists of the interaction between two neural networks: a generator that creates 3D panel component geometries and an evaluator that predicts their post-stamping thinning distributions. Guided by these distributions the geometry is iteratively updated by a gradient-based optimisation technique. In the application presented in this paper, panel component geometries are optimised to meet imposed constraints that are derived from post-stamping thinning distributions. In addition, a new methodology is applied to select arbitrary geometric regions that are to be fixed during the optimisation. Overall, it is demonstrated that the platform is capable of optimising selective regions of panel component subject to imposed post-stamped thinning distribution constraints

Implicit Simulations using Messaging Protocols

A novel algorithm for performing parallel, distributed computer simulations on the Internet using IP control messages is introduced. The algorithm employs carefully constructed ICMP packets which enable the required computations to be completed as part of the standard IP communication protocol. After providing a detailed description of the algorithm, experimental applications in the areas of stochastic neural networks and deterministic cellular automata are discussed. As an example of the algorithms potential power, a simulation of a deterministic cellular automaton involving 10^5 Internet connected devices was performed.Comment: 14 pages, 3 figure

Rapid feasibility assessment of components to be formed through hot stamping: A deep learning approach

The novel non-isothermal Hot Forming and cold die Quenching (HFQ) process can enable the cost-effective production of complex shaped, high strength aluminium alloy panel components. However, the unfamiliarity of designing for the new process prevents its widescale adoption in industrial settings. Recent research efforts focus on the development of advanced material models for finite element simulations, used to assess the feasibility of new component designs for the HFQ process. However, FE simulations take place late in design processes, require forming process expertise and are unsuitable for early-stage design explorations. To address these limitations, this study presents a novel application of a Convolutional Neural Network (CNN) based surrogate as a means of rapid manufacturing feasibility assessment for components to be formed using the HFQ process. A diverse dataset containing variations in component geometry, blank shapes, and processing parameters, together with corresponding physical fields is generated and used to train the model. The results show that near indistinguishable full field predictions are obtained in real time from the model when compared with HFQ simulations. This technique provides an invaluable tool to aid component design and decision making at the onset of a design process for complex-shaped components formed under HFQ conditions