Maximum power point tracker for solar arrays using controlled rectifier.

Solar energy offers a large potential as a source of energy and in light of financial and ethical reasons, people are looking to harvest it for their energy needs. The conversion of solar energy to electricity is performed by solar cells. There exists an operating point associated with solar cells at which the power generated is maximized at any given point in time. A maximum power point tracker (MPPT) is required to track this maximum power operating point (MPOP). A wide range of systems exists to meet this purpose. This thesis explores the use of a single-phase controlled rectifier, with back stepping control to track the maximum power from a string of solar arrays. This controller tracks the MPOP using a circuit topology that has been under investigation within the literature and was simulated using MA TLAB/Simulink. Simulation results showed that the designed converter and control strategy could transfer power from a string of solar arrays to the grid by efficiently tracking the MPOP

Reasons for Hospitalization and All-Cause Mortality for Adults with Sarcoidosis

Purpose: Sarcoidosis is a multisystem immune disease with a high rate of hospitalization. There is a paucity of large population-based studies on sarcoid inpatients. We aimed to examine the reasons for hospitalizations and mortality of adult sarcoid patients utilizing the National Inpatient Sample (NIS) database. Methods: Adult hospitalizations in 2016-2019 NIS database with sarcoidosis (ICD-10 code D86) were analyzed. The “reason for hospitalization” and “reason for in-hospital death” were divided into 19 organ system/disease categories based on their principal ICD-10 hospital billing diagnosis. Results: Among the 330,470 sarcoid hospitalizations, cardiovascular (20.4%) and respiratory (16.9%) diagnoses were the most common reasons for hospitalization. The most common individual diagnoses were sepsis and pneumonia. In-hospital death occurred in 2.4% of sarcoid hospitalizations. The most common reasons for death were infectious (30%), cardiovascular (20.7%), and respiratory (20.3%) diagnoses. The most common individual diagnoses in the deceased group were sepsis and respiratory failure. Finally, the sarcoid group had a higher frequency of complications including arrhythmias/heart blocks, heart failure, cranial neuropathies, hypercalcemia, iridocyclitis, myocarditis, and myositis. Sarcoid inpatients had longer length of stay (4 vs 3 days; p < .001) and higher median total hospital charges ($36,865 vs$31,742; p < .001). Conclusions: The most common reasons for sarcoid hospitalizations were cardiovascular and respiratory. Nearly 1 in 40 hospitalizations resulted in death, with most common complications being conduction abnormalities and heart failure. The most common causes of in-hospital death were sepsis and respiratory failure. Sarcoid hospitalizations had 16% higher total hospital charges compared to nonsarcoid inpatients

Reasons for hospitalization and in-hospital mortality in adult systemic lupus erythematosus

OBJECTIVE: Systemic lupus erythematosus (SLE) is an autoimmune disease with an increased risk of hospitalization. Multiple studies have reported SLE flare, infection, and cardiovascular (CV) events as the most common reasons for hospitalization. The aim of this study was to use a large US population-based database to comprehensively analyze all indications for adult SLE hospitalization and reasons for in-hospital mortality. METHODS: We conducted a retrospective study of SLE hospitalizations in 2017 from the National Inpatient Sample database. The reason for hospitalization and reason for in-hospital mortality in patients with SLE were divided into 19 categories based on their principal International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10) diagnosis. RESULTS: A total of 180 975 hospitalizations carried either a principal or secondary ICD-10 code for SLE. The leading reasons for hospitalization were CV (16%), rheumatologic (13%), infectious (11%), respiratory (10%), and gastrointestinal (10%). SLE itself was the principal diagnosis in only 6% of the hospitalizations. In-hospital death occurred in 1 of every 50 SLE hospitalizations. Infectious (37%) and CV diagnoses (21%) were the most common reasons for in-hospital death, with sepsis being the most frequent reason for death. CONCLUSION: This analysis represents the only report to date that comprehensively categorizes the reasons for hospitalization and reasons for in-hospital mortality of patients with SLE on a US national level. SLE itself was the principal diagnosis for only a small percentage of hospitalizations. CV diagnoses were the most common reason for hospitalization. In-hospital death occurred in 1 of every 50 SLE hospitalizations. Infectious and CV diagnoses were the most common reason for in-hospital death