Search Results (3)

To maintain the stability of the power system, frequency fluctuations must be reduced in the shortest possible timeframe. Load frequency control (LFC) plays a critical role in achieving this objective by regulating the system frequency and the desired demand or output power in an interconnected network, thereby enabling the system to adapt the load disturbances. In order to effectively mitigate the frequency fluctuation caused by load variation in a single-area power system, a new control strategy integrating a linear quadratic regulator (LQR), a proportional controller, and a damping compensator is proposed in this paper. The proposed controller is named as the LQR-based proportional damping compensator which mitigates the frequency fluctuation of a single-area power system. MATLAB/Simulink simulation is conducted on a single-area power system to demonstrate the efficacy of the proposed control technique. The simulation results demonstrate that the proposed method successfully reduces frequency variations, maintains system frequency within reasonable limits, and substantially reduces the settling time as compared to other existing control techniques. Apart from the simulation analysis, to experimentally validate the performance of the proposed controller, a hybrid multiprocessor-based processor-in-loop (PIL) technique is also introduced in the paper. Both the simulation and experimental results prove the promising performance of the proposed controller for mitigating the frequency fluctuation of a single-area power system. Full article

One major micronutrient studied for its possible protective effect against the COVID-19 disease is vitamin D. This systematic review sought to identify and synthesize available evidence to aid the understanding of the possible effect of vitamin D deficiency on COVID-19 status and health outcomes in COVID-19 patients. Three databases (PubMed, ScienceDirect, and Google Scholar) were systematically used to obtain English language journal articles published between 1 December 2019 and 3 November 2020. The search consisted of the terms (“Vitamin D,” OR “25-Hydroxyvitamin D,” OR “Low vitamin D.”) AND (“COVID-19” OR “2019-nCoV” OR “Coronavirus” OR “SARS-CoV-2”) AND (“disease severity” OR “IMV” OR “ICU admission” OR “mortality” OR “hospitalization” OR “infection”). We followed the recommended PRISMA guidelines in executing this study. After going through the screening of the articles, eleven articles were included in the review. All the included studies reported a positive association between vitamin D sufficiency and improved COVID-19 disease outcomes. On the other hand, vitamin D deficiency was associated with poor COVID-19 disease outcomes. Specifically, two studies found that vitamin D-deficient patients were more likely to die from COVID-19 compared to vitamin D-sufficient patients. Three studies showed that vitamin D-deficient people were more likely to develop severe COVID-19 disease compared to vitamin D-sufficient people. Furthermore, six studies found that vitamin D-deficient people were more likely to be COVID-19 infected compared to vitamin D-sufficient people. Findings from these studies suggest that vitamin D may serve as a mitigating effect for COVID-19 infection, severity, and mortality. The current evidence supports the recommendations for people to eat foods rich in vitamin D such as fish, red meat, liver, and egg yolks. The evidence also supports the provision of vitamin D supplements to individuals with COVID-19 disease and those at risk of COVID-19 infection in order to boost their immunity and improve health outcomes. Full article

Intimate partner violence has been associated with numerous consequences for women, including pregnancy termination. This study examined the association between predictive capacity of intimate partner violence and pregnancy termination among women in Armenia. The study analyzed the 2015–16 Armenia Demographic and Health Survey (ADHS) data on women aged 15–49 (Mean: 31.49; Standard Deviation, SD: 9.51). Marital control exercised by husbands, ever experienced physical violence, sexual violence, and emotional violence by husbands were the four indicators of intimate partner violence used in this study. To assess the association between intimate partner violence and pregnancy termination, a binary logistic regression model was fitted. After controlling for confounders, we found that women whose husbands exercised marital control were 26% more likely to experience pregnancy termination, compared to women whose husbands did not exercise marital control (adjusted odds ratio (aOR): 1.26, 95% Confidence interval (CI): 1.03–1.53). Women who ever experienced sexual violence were about 10 times likely to experience pregnancy termination than women who did not experience sexual violence (aOR: 9.76, 95% CI: 1.91–49.96). Both ever experienced physical violence and emotional violence did not have any significant associations with pregnancy termination. Forms of intimate partner violence are associated with pregnancy termination. The findings of this study provide evidence for government and policymakers to formulate, modify, and implement policies and program that target both men and women regarding the prevailing intimate partner violence and its consequences. Strengthening the policy implementation will ensure that women are empowered to make decisions about their reproductive health. Making husbands and their family members aware of the basics and consequences of intimate partner violence and focusing on child cognitive development which can be hampered due to the prevalence violence in families are recommended. Full article