Clinical profiles of patients undergoing permanent pacemaker implantation in a tertiary care hospital in India

Background: Despite an increase in the number of permanent pacemaker implantations in India over the last few decades, there are no systematic nationwide database recording the rate of implantation of permanent pacemaker, clinical conditions or types of pacemakers used for PPM implantation in India. Methods: A total of 5341 patients, admitted in the department of cardiology, Institute of Post Graduate Medical Education and Research, West Bengal, India from April, 2019 to August 2023 and received a permanent pacemaker were included in the study. Objective of the study was to provide information about the clinical profile and indications of patients receiving permanent pacemaker implantation (PPI). Results: Most (67%) of the recipients among the study population were males. The mean (± SD) age of patients in the present cohort was 63.59±11.82 years. The most frequent type of pacemaker used in this institution was VVIR (86.2%). The mean impedance for DDDR type pacemakers was 599.7±109.19 (range =416-1074) for ventricle and 915.9±116.2 (range =525-1240) for the atrium, while the threshold of DDDR type was 0.5±0.3 (range =0.1 -3) for ventricles and 0.3±0.2 (range =0.1-1.3) for the atrium. For VVIR type of pacemakers, the impedance for ventricles was 918.5±131.1 (range =120-1620), while the threshold for ventricle was 0.3±0.2 (range =0.1-2.2). The commonest indication of pacemakers were AV blocks (69%), of which the commonest was complete heart block (59.7%). Conclusions: In conclusion, male population were implanted with a higher number of pacemakers than females. No difference in age was noted among males and females in terms of the age of implantation. Use of single chamber VVIR types were higher than the dual chamber due to the pattern of government supply of pacemakers. Most common indication for pacemaker implantation was degenerative complete heart block

Robust fuzzy-sliding mode based UPFC controller for transient stability analysis in autonomous wind-diesel-PV hybrid system

This study presents a comparative study of transient stability and reactive power compensation issues in an autonomous wind–diesel-photovoltaic based hybrid system (HS) using robust fuzzy-sliding mode based unified power flow controller (UPFC). A linearised small-signal model of the different elements of the HS is considered for the transient stability analysis in the HS under varying loading conditions. An IEEE type 1 excitation system is considered for the synchronous generator in the HS, with negligible saturation characteristic, for detailed voltage stability analysis. It is noted from the simulation results that the performance of UPFC is superior to static VAR compensator and static synchronous compensator in improving the voltage profile of the HS. Further, fuzzy and fuzzy-sliding mode based UPFC controller is designed in order to improve the transient performance. Simulation results reflect the robustness of the proposed fuzzy-sliding mode controller for better reactive power management to improve the voltage stability in comparison with the conventional PI and fuzzy-PI controllers. In addition to this, system stability analysis is performed based on eigenvalue, bode and popov for supporting the robustness of the proposed controller

Bacterial Foraging Optimized STATCOM for Stability Assessment in Power System

This paper presents a study of improvement in stability in a single machine connected to infinite bus (SMIB) power system by using static compensator (STATCOM). The gains of Proportional-Integral-Derivative (PID) controller in STATCOM are being optimized by heuristic technique based on Particle swarm optimization (PSO). Further, Bacterial Foraging Optimization (BFO) as an alternative heuristic method is also applied to select optimal gains of PID controller. The performance of STATCOM with the above soft-computing techniques are studied and compared with the conventional PID controller under various scenarios. The simulation results are accompanied with performance indices based quantitative analysis. The analysis clearly signifies the robustness of the new scheme in terms of stability and voltage regulation when compared with conventional PID

Bacterial Foraging Optimized STATCOM for Stability Assessment in Power System

This paper presents a study of improvement in stability in a single machine connected to infinite bus (SMIB) power system by using static compensator (STATCOM). The gains of Proportional-Integral-Derivative (PID) controller in STATCOM are being optimized by heuristic technique based on Particle swarm optimization (PSO). Further, Bacterial Foraging Optimization (BFO) as an alternative heuristic method is also applied to select optimal gains of PID controller. The performance of STATCOM with the above soft-computing techniques are studied and compared with the conventional PID controller under various scenarios. The simulation results are accompanied with performance indices based quantitative analysis. The analysis clearly signifies the robustness of the new scheme in terms of stability and voltage regulation when compared with conventional PID

Copper thiocyanate (CuSCN): an efficient solution-processable hole transporting layer in organic solar cells

Here, we report copper(I) thiocyanate (CuSCN) as an efficient and solution-processable hole transport layer (HTL) in bulk heterojunction solar cells. Three different combinations of the most studied active layers of P3HT:PC61BM, PCDTBT:PC71BM and PTB7:PC71BM were used for photovoltaic device fabrication with the simplest device structure of ITO/CuSCN/active layer/Al. The use of CuSCN as an HTL has improved light absorption within the active layer and thereby leads to up to 5.94% and 4.60% power conversion efficiencies (PCEs) for the active layers of PCDTBT:PC71BM and PTB7:PC71BM, respectively. These results are slightly better when compared to the devices fabricated using thermal deposition of MoO3 and solution processed deposition of PEDOT: PSS as an HTL under similar conditions. We have observed that the annealing temperature for HTLs in organic solar cells has a significant effect on the PCE, specifically the fill factor (FF) and short-circuit current (J(sc)). In the present work, the resulting HTLs were characterized using UV-vis-NIR spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM) and transmission electron microscopy (TEM) for better understanding. Finally, we have provided a further example of solution-processable CuSCN as an efficient HTL in organic solar cells, in general

Effects of Bt-cotton on biological properties of Vertisols in central India

Growing areas under transgenic crops have created a concern over their possible adverse impact on the soil ecosystem. This study evaluated the effect of Bt-cotton based cropping systems on soil microbial and biochemical activities and their functional relationships with active soil carbon pools in Vertisols of central India (Nagpur, Maharastra, during 2012–2013). Culturable groups of soil microflora, enzymatic activities and active pools of soil carbon were measured under different Bt-cotton based cropping systems (e.g. cotton-soybean, cotton-redgram, cotton-wheat, cotton-vegetables and cotton-fallow). Significantly higher counts of soil heterotrophs (5.7–7.9 log cfu g−1soil), aerobic N-fixer (3.9–5.4 log cfu g−1soil) and P-solubilizer (2.5−3.0 log cfu g−1soil) were recorded in Bt-cotton soils. Similarly, soil enzymatic activities, viz. dehydrogenase (16.6–22.67 µg TPF g−1 h−1), alkaline phosphatase (240–253 µg PNP g−1 h−1) and fluorescein di-acetate hydrolysis (14.6–18.0 µg fluorescein g−1 h−1), were significantly higher under Bt-cotton-soybean system than other Bt- and non-Bt-cotton based systems in all crop growth stages. The growth stage-wise order of soil microbiological activities were: boll development > harvest > vegetative stage. Significant correlations were observed between microbiological activities and active carbon pools in the rhizosphere soil. The findings indicated no adverse effect of Bt-cotton on soil biological properties

Layer-by-layer versus copolymer: Opto-electrochemical properties of 1,3,5-Tris(N-carbazolyl)benzene and EDOT based polymers

Polymer deposition directly from monomer(s) is important for different applications in wide fields. Layer-by-layer thin film PTCB-layer-PEDOT was deposited by the successive electrochemical polymerization of 1,3,5-tris(N-carbazolyl)benzene (TCB) and 3,4-ethylenedioxythiophene (EDOT) using 0.1 M TBAPF(6) in CH2Cl2. For comparison purpose, copolymers P(TCB-co-EDOT) along with corresponding homopolymers (PTCB and PEDOT) were prepared systematically by electrochemical polymerization under identical conditions. A systematic study of cyclic voltammetry (CV), stability, impedance spectroscopy, spectroelectrochemistry and electrochromic properties of all the polymers are reported where applicable. The results revealed that CV and spectroelectrochemistry could be a powerful technique to characterize these polymer films. In contrast to layer-by-layer polymer, copolymer exhibits new properties compared to the corresponding homopolymers. Further, a series of copolymers P(TCB-co-EDOT) were prepared from the different molar ratio of monomers and we achieved the band gap control in the copolymers. (C) 2019 Elsevier B.V. All rights reserved

Influence of gravity on torsional surface waves in a dissipative medium

El presente artículo trata sobre las posibilidades de propagación de ondas superficiales torsionales en un medio viscoelástico bajo campo de gravedad. Durante el estudio, se pudo observar que el aumento del parámetro de gravedad aumenta, a su vez, la velocidad de la onda, mientras que el incremento del parámetro viscoelástico disminuye la velocidad de la onda, hasta que el producto de la frecuencia angular y el parámetro viscoelástico sea menor a la unidad. También, se observó que a medida que aumenta la velocidad la curva se vuelve asintótica por naturaleza cuando se incrementa el período de tiempo de oscilación. De hecho, la máxima amortiguación de la velocidad también se ha identificado en este punto de corte, que puede considerarse como el punto en el que un material viscoelástico se convierte en un medio viscoso. Se calcularon los coeficientes de absorción para diferentes valores de parámetro viscoelástico y campo de gravedad. El estudio reveló que el medio espacio viscoelástico en ausencia de campo de gravedad no permite ondas superficiales de torsión, mientras que en presencia de campo de gravedad las ondas se propagan y amortiguan. doi: https://doi.org/10.22201/igeof.00167169p.2021.60.1.191

Selenium-Containing pi-Conjugated Polymers for Organic Solar Cells

Organic solar cell research has attracted scientific and commercial interest in the last decade due to a rapid increase in power conversion efficiencies (PCEs). Today, PCEs in the range of 8-10% have been obtained using conjugated polymers as electron-donor materials in combination with fullerene/other acceptors. However, to enable commercial applications, the efficiencies and lifetimes of organic solar cells still need to be improved significantly. In recent years, due to the potential advantages of Se-containing conjugated materials, namely, lower band gaps, rigidity, and strong Se Se integration, have attracted surprising attention for use in organic solar cells. In this review, we focus on the synthesis and applications of Se-containing conjugated polymers for organic solar cells and throughout compare them with S- and O-containing analogues where applicable. The relationships between the chemical structures and properties, such as absorptions, energy levels, mobilities, and photovoltaic behavior, are also discussed

An eco-friendly and inexpensive solvent for solution processable CuSCN as a hole transporting layer in organic solar cells

During past few years, significant research on solution-processable deposition of copper(I)thiocyanate (CuSCN) as an efficient hole transporting layer (HTL) for excitonic solar cells have been successfully reported. Surprisingly, till now only two solvents diisopropyl sulfide and diethyl sulfide are known which have been used for CuSCN film deposition as a HTL for device fabrication. Here, we have used ecofriendly and inexpensive solvent dimethyl sulfoxide (DMSO) for solution processed thin film deposition of CuSCN for organic solar cells. The photovoltaic devices were fabricated using two different donor polymers PCDTBT and PTB7 blended with PC71BM as an acceptor material with device structure of ITO/CuSCN/active layer/Al. The power conversion efficiency (PCE) based on CuSCN using DMSO as a deposition solvent have been achieved up to 4.20% and 3.64% respectively, with relative higher fill factor (FF) as compared to previously reported values in literature. The resultant HTLs were characterized by UV vis NIR spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM) and atomic force microscope (AFM) for better understanding