23 research outputs found
An Investigation on The Impacts of Inverter Modulation Techniques on The Performance of The Dual Inverter Drive
This work presents a comprehensive overview about the dual inverter drives in applications related to the electric vehicle industry. The requirement of efficient and integrated power electronic converter circuits has become an essential requirement to the vehicle function. Major research and progress have been made to achieve dual and bidirectional operation of power flow, while minimizing losses, volume and costs. This thesis surveys the single, three phase, and dual inverter structure and operation. The dual structures are earning growing attention due to their capability to provide multiple output voltages to the stator of the electric machine associated with the electric vehicle. The contribution of this work is to study the impact of the major modulation techniques on the regulated, dual inverter drive performance. The selected methods for evaluation include sinusoidal pulse width modulation, third harmonic injection pulse width modulation, and space vector modulation in terms of the drive’s output voltage, fundamental voltage and total harmonic distortion. The second investigation involves the manipulation of phase angle relationships between the gates of the two adjacent inverters, allowing the drive to achieve equal phase voltage and power between both inverters at varying loads
Mechanisms of Diabetes Mellitus-Induced Sudden Cardiac Death
More than 450 million people worldwide have diabetes mellitus (DM), a metabolic disorder characterized by an increase in blood glucose level (hyperglycemia) that arises from insufficient insulin secretion or resistance to insulin’s action. More than 70% of individuals with chronic DM will develop cardiovascular diseases (CVDs) including atherosclerosis and coronary artery diseases (CADs), hypertension, cardiac arrhythmias, cardiomyopathy (heart failure), stroke, and chronic kidney disease. A significant number of these individuals will also succumb to sudden cardiac death (SCD). SCD usually occurs in early morning from abnormal heart rhythms or arrhythmias and ventricular fibrillation. When the pumping action of the heart becomes erratic, a reduction in oxygenated blood to the brain leads to unconsciousness and brain damage. SCD is independent of age and sex and positively correlates with impairment in cardiac metabolism, muscle damage, fibrosis, apoptosis, hypertrophy, ischemia, and deranged cation signaling. This review centers on mechanisms by which intracellular cations (Na+, K+, and Ca2+) handling, inflammation, and oxidative and carbonyl stresses due to diabetes-induced hyperglycemia can lead to the deterioration of excitation/contraction coupling (ECC), impaired contractility, arrhythmias, and SCD in DM patients. It also discusses the beneficial effects of exercise training to attenuate the risk of SCD
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Cigarette Smoke Toxins Deposited on Surfaces: Implications for Human Health
Cigarette smoking remains a significant health threat for smokers and nonsmokers alike. Secondhand smoke (SHS) is intrinsically more toxic than directly inhaled smoke. Recently, a new threat has been discovered – Thirdhand smoke (THS) – the accumulation of SHS on surfaces that ages with time, becoming progressively more toxic. THS is a potential health threat to children, spouses of smokers and workers in environments where smoking is or has been allowed. The goal of this study is to investigate the effects of THS on liver, lung, skin healing, and behavior, using an animal model exposed to THS under conditions that mimic exposure of humans. THS-exposed mice show alterations in multiple organ systems and excrete levels of NNAL (a tobacco-specific carcinogen biomarker) similar to those found in children exposed to SHS (and consequently to THS). In liver, THS leads to increased lipid levels and non-alcoholic fatty liver disease, a precursor to cirrhosis and cancer and a potential contributor to cardiovascular disease. In lung, THS stimulates excess collagen production and high levels of inflammatory cytokines, suggesting propensity for fibrosis with implications for inflammation-induced diseases such as chronic obstructive pulmonary disease and asthma. In wounded skin, healing in THS-exposed mice has many characteristics of the poor healing of surgical incisions observed in human smokers. Lastly, behavioral tests show that THS-exposed mice become hyperactive. The latter data, combined with emerging associated behavioral problems in children exposed to SHS/THS, suggest that, with prolonged exposure, they may be at significant risk for developing more severe neurological disorders. These results provide a basis for studies on the toxic effects of THS in humans and inform potential regulatory policies to prevent involuntary exposure to THS
Built-in-Self-Test and Digital Self-Calibration for RF SoCs
This book will introduce design methodologies, known as Built-in-Self-Test (BiST) and Built-in-Self-Calibration (BiSC), which enhance the robustness of radio frequency (RF) and millimeter wave (mmWave) integrated circuits (ICs). These circuits are used in current and emerging communication, computing, multimedia and biomedical products and microchips. The design methodologies presented will result in enhancing the yield (percentage of working chips in a high volume run) of RF and mmWave ICs which will enable successful manufacturing of such microchips in high volume.
Organic Floating-Gate Memory Structures
[No abstract available]Scopu