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A novel configuration is studied where a doubly fed induction generator provides power to a squirrel-cage induction motor, and the speed of the motor is controlled through the rotor-side converter of the generator. Such topology could have applications in hybrid-electric propulsion and would require fewer and smaller power electronic converters than a system with an intermediate DC bus. An integrated motor/generator set model is developed to reflect the tightly connected dynamics of the combined electric machine. To simplify the derivations, a representation in complex variables is used. However, the control algorithm is based on proven field-oriented control principles for induction motors. Feedforward and feedback control algorithms of the induction motor integrated with the doubly fed induction generator are proposed, together with two methods to limit the rotor currents of the generator. Experimental data show excellent tracking performance of speed references, demonstrating the validity of the control methods proposed. Concepts are also presented for the management of a small energy storage component. [ABSTRACT FROM AUTHOR]

A traditional hybrid-electric propulsion system requires two full-rated converters to convert the electric power from the generator to motor. This brief proposes a method to control the speed of a permanent-magnet synchronous motor (PMSM) receiving power from a doubly fed induction generator (DFIG) and using the generator’s rotor-side converter. This technique can reduce the size and number of converters in a hybrid-electric propulsion system. An integrated model of the system is developed, which is then used to derive the control algorithm. The presentation is simplified by using a complex representation of the dynamic system and of the control law. A voltage and a current command mode are considered and limiting is incorporated to ensure the satisfaction of current constraints. Experimental data show excellent tracking performance of speed references and improved recovery from large load disturbances compared with operation using a synchronous generator. A storage element provides or recovers excess power through the rotor-side converter of the DFIG. [ABSTRACT FROM AUTHOR]

Cascading blackouts are the oldest major unsolved technical problem in power system engineering, highly visible since the Northeast Blackout of 1965 in North America. In this article, we review some cascading blackouts and past work on the problem. New metrics measure network stress to identify and reduce the risk of cascading failures. [ABSTRACT FROM AUTHOR]

Lung diseases including chronic obstructive pulmonary disease (COPD), infections like influenza, acute respiratory distress syndrome (ARDS), asthma and pneumonia lung cancer (LC) are common causes of sickness and death worldwide due to their remoteness, cold and harsh climatic conditions, and inaccessible health care facilities. Many drugs have already been proposed for the treatment of lung diseases. Few of them are in clinical trials and have the potential to cure infectious diseases. Plant extracts or herbal products have been extensively used as Traditional Chinese Medicine (TCM) and Indian Ayurveda. Moreover, it has been involved in the inhibition of certain genes/protiens effects to promote regulation of signaling pathways. Natural remedies have been scientifically proven with remarkable bioactivities and are considered a cheap and safe source for lung disease. This comprehensive review highlighted the literature about traditional plants and their metabolites with their applications for the treatment of lung diseases through experimental models in humans. Natural drugs information and mode of mechanism have been studied through the literature retrieved by Google Scholar, ScienceDirect, SciFinder, Scopus and Medline PubMed resources against lung diseases. In vitro , in vivo and computational studies have been explained for natural metabolites derived from plants (like flavonoids, alkaloids, and terpenoids) against different types of lung diseases. Probiotics have also been biologically active therapeutics against cancer, anti-inflammation, antiplatelet, antiviral, and antioxidants associated with lung diseases. The results of the mentioned natural metabolites repurposed for different lung diseases especially for SARS-CoV-2 should be evaluated more by advance computational applications, experimental models in the biological system, also need to be validated by clinical trials so that we may be able to retrieve potential drugs for most challenging lung diseases especially SARS-CoV-2. [Display omitted] [ABSTRACT FROM AUTHOR]

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the novel coronavirus responsible for the current global pandemic, which first emerged in December 2019. This coronavirus has affected 217 countries worldwide, most of which have enacted non-remedial preventive measures, such as nationwide lockdowns, work from home, travel bans, and social isolation. Pharmacists, doctors, nurses, technologists, and other healthcare professionals have played pivotal roles during this pandemic. Unfortunately, confirmed drugs have not been identified for the treatment of patients with coronavirus disease 2019 (COVID-19) caused by SARSCoV2; however, favipiravir and remdesivir have been reported as promising antiviral drugs. Some vaccines have already been developed, and vaccination is ongoing globally. Various nanotechnologies are currently being developed in many countries for preventing SARS-CoV-2 spread and treating COVID-19 infections. In this article, we present an overview of the COVID-19 pandemic situation and discuss nanotechnology-based approaches and investigational therapeutics for COVID-19., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)