Equivalent Input Disturbance-Based Control Design for Three Phase Dual-Stage Grid-Tied Photovoltaic System Considering Dead Time Effect

Grid-tied inverter is the prominent component of the three-phase dual-stage photovoltaic (PV) grid-tied power generation system. However, the disturbances caused by dead time effect will pose the reduction of grid-tied current quality and even cause the imbalance of inverter itself or other circuit devices. In this paper, a current control strategy is proposed to damp dead time effect for the three-phase dual-stage PV grid-tied inverter system, and its design, stability analysis, and implementation are carried out. First, the inverter model is modified by regarding the dq reference frame coupling terms, uncertainties, and external and internal disturbances as an unknown lumped disturbance. Then, a current control scheme based on compensation of equivalent input disturbance is introduced, and it estimates and compensates the unknown lumped disturbance, which effectively realizes the inverter model decoupling and comprehensive disturbance rejection. Last, simulation results demonstrate the effectiveness and superiority of the proposed current controller.

GROWTH OF COPPER SULPHIDE CRYSTAL IN GEL AND ITS THERMAL SPECTROSCOPIC SEMICONDUCTING CHARACTERISATIONS WITH KINETIC PARAMETERS

Copper sulphides crystals are grown using simple gel technique at ambient temperature. The various lattice parameters, gel aging time, gel setting time, Effect of pH observed, Different characterization like gel aging, pH of gel ,setting of gel with their analysis and Thermal behavior of grown crystal like Thermo gravimetric Analysis TGA are Discussed. The chemical analysis confirmed contents in grown crystal of copper sulphides

Observing time effect of SSRIs on suicide risk and suicide-related behaviour: a network meta-analysis protocol

IntroductionSuicide is a serious problem worldwide and 90% cases are associated with pre-existing or underlying mental illness. As a common treatment for depressive symptoms that suicidal people may receive, selective serotonin reuptake inhibitors (SSRIs) have been linked to a possible increase in suicide rates. Studies focusing on SSRIs and suicide have produced inconsistent results, suggesting that use of SSRIs decreases, increases, has no effect on suicide rates, or that the effect of SSRIs on suicide is age-dependent. This protocol of network meta-analysis aims to precisely evaluate the time effects of SSRIs by observing weekly changes of suicidality in the first 2 months of the treatment, and consequently, to explore whether the effect of the SSRIs on suicide varies depending on the stages of the treatment; if so, we will identify the turning point.Methods and analysisWe will search in the following databases: PubMed, Web of science, China National Knowledge Infrastructure and Wanfang Data, from dates of inception to 9 July 2021, with language restricted to English and Chinese. Studies focusing on the time effect of SSRIs on suicide will be retrieved. Then, the study selection process will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline, and the quality assessment will be conducted with Cochrane Collaboration’s tool. Two researchers will work independently on data extraction using a standardised data extraction spreadsheet. Any disagreement between two researchers will be discussed and determined by a third researcher.Ethics and disseminationThis work does not require ethics approval as it will be based on published studies. This review will be published in peer-reviewed journals.PROSPERO registration numberCRD42021244779.

Evaluation of the effects of the national diabetes control and prevention program on a sample of iranian people with type 2 diabetes

Diabetes prevention programs have been developed in the different countries and it is therefore necessary to gain a better understanding of factors affecting the effectiveness of these programs for each society. Accordingly, the purpose of this study was to evaluate the effect of the National Diabetes Control and Prevention Program (NDCPP) on the biochemical and anthropometric indices among a sample of Iranian patients with type 2 diabetes mellitus (T2DM). A total of 384 patients with T2DM from the primary health care system of Tehran and Tabriz cities during January to June 2020, were included in the study. A two-part questionnaire consisting of items related to socio-economic and demographic characteristics was used and biochemical and anthropometric indices were measured at the beginning and the end of the 3-month intervention period. There was a significant difference in fasting blood sugar (FBS), hemoglobin glycosides (HbA1 C), systolic blood pressure (SBP) and weight before and after the NDCPP (P < 0.001). Also, there was significant improvement in carbohydrate (P = 0.015) and protein intake (P = 0.027) after the NDCPP compared to before the study. No significant difference was observed in waist circumference (WC) (P = 0.689), body mass index (P = 0.784), diastolic blood pressure (P = 0.647), and other dietary nutrient intake before and after the NDCPP. Repeated measure ANOVA revealed a significant decrease in FBS (Time effect P = 0.019) and weight (Time effect P = 0.006) after the NDCPP. Also, residing in different cities had a significant effect on FBS (time×city effect P < 0.001), HbA1 C (time×city effect P < 0.001), and SBP (time×city effect P = 0.037) after the NDCPP. The NDCPP resulted in weight loss, improved HbA1 C, and FBS. These findings suggested that NDCPP had a positive effect on controlling T2DM among Iranian population and can be considered as a way to prevent complications of T2DM.