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Polymer Nanocomposite Graphene Quantum Dots for High-Efficiency Ultraviolet Photodetector
Influence on photocurrent sensitivity of hydrothermally synthesized electrochemically active graphene quantum dots on conjugated polymer utilized for a novel single-layer device has been performed. Fabrications of high-performance ultraviolet photodetector by depositing the polypyrrole-graphene quantum dots (PPy-GQDs) active layer of the ITO electrode were exposed to an Ultraviolet (UV) source with 265 and 355 nm wavelengths for about 200 s, and we examined the time-dependent photoresponse. The excellent performance of GQDs was exploited as a light absorber, acting as an electron donor to improve the carrier concentration. PGC4 exhibits high photoresponsivity up to the 2.33 A/W at 6 V bias and the photocurrent changes from 2.9 to 18 A. The electrochemical measurement was studied using an electrochemical workstation. The cyclic voltammetry (CV) results show that the hysteresis loop is optically tunable with a UV light source with 265 and 355 nm at 0.1 to 0.5 V/s. The photocurrent response in PPy-GQDs devices may be applicable to optoelectronics devices. 2022 by the authors. -
Polymer-Carbon nanocomposite: Synthesis, optical and biocidal properties
Microorganism contamination of food storage, water treatment, pharmaceuticals, and especially biomedical equipment is a severe problem. Bacteria frequently contaminate permanent implantations after long-term usage. To successfully treat these infections, it is essential to monitor microbial activity and know how it interacts with antibodies in real-time. In this work, a nanocarbon-polymer nanocomposite (ARPD) is successfully developed, and its antibacterial activity against selected microorganisms is successfully validated. Obtained antibacterial results confirm that the photoluminescent ARPD demonstrated outstanding antibacterial action against the microorganism Escherichia coli from the selected group of bacteria. The fluorescent diagnostics and treatments offer exciting possibilities for the luminescence and biocidal activity of nanocomposite produced from ARH-PVDF nanomaterials. 2023 The Author(s) -
Polyoxometalate/?-Fe2O3/polyaniline composite: Tailored approaches for high-performance supercapacitors
The need for portable, high-performance electronics that have high power or energy density has increased significantly in recent years. In this work, a composite material was coated on stainless steel that consists of polyoxometalate (POM)/?-Fe2O3/polyaniline (PANI) as an electrode material for a symmetric supercapacitor. ?-Fe2O3 was prepared using starch as a template while PANI was electrodeposited. The physical and chemical characteristics of the modified electrodes were investigated via Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and electrochemical techniques such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge[sbnd]discharge (GCD) experiments. In 1 M H2SO4, the composite had a specific capacitance of 528 F/g at a current density of 0.2 A/g. In addition, the composite exhibited a high energy density of 73.4 Wh kg?1 at a high-power density of 7.14 kW kg?1 and 91.62 % capacity retention after 10 cycles. The results show that POM/?-Fe2O3/PANI is a promising composite electrode for use as a supercapacitor electrode material. 2024 The Authors -
Polyphenol composition and antioxidant activity of andrographis paniculata L. nees /
Mapana Journal of Sciences, Vol.13, Issue 4, pp.481-494, ISSN No: 0975-3303 (Print) -
Polypyrrole functionalized MoS2 for sensitive and simultaneous determination of heavy metal ions in water
Assessing heavy metal ion (HMI) contamination to sustain drinking water hygiene is a challenge. Conventional approaches are appealing for the detection of HMIs but electrochemical approaches can resolve the limitations of these approaches, such as tedious sample preparation, high cost, time consuming and the need for trained professionals. Here, an electrochemical approach is developed using a nano-sphered polypyrrole (PPy) functionalized with MoS2 (PPy/MoS2) by square wave anodic stripping voltammetry for the detection of HMIs. The developed sensor can detect Pb2+ with a limit of detection of 0.03 nM and a sensitivity of 36.42 ?A nM?1. Additionally, the PPy/MoS2 sensor was employed for the simultaneous detection of HMIs of Cd2+, Pb2+, Cu2+ and Hg2+. The reproducibility, stability and anti-interference studies confirm that the sensor can be used to monitor HMI contamination of water. 2025 The Royal Society of Chemistry. -
Polypyrrole- silver nanocomposite for enhanced photocatalytic degradation of methylene blue under sunlight irradiation
Polypyrrole (Ppy) -Silver nanocomposite samples have been synthesised by chemical oxidative polymerisation. The characteristic peaks of face centered cubic (fcc) structure of silver in XRD confirmed its presence in Ppy. Shift in NH stretching frequency observed in FTIR spectroscopy revealed the coordination of silver into Ppy. The photocatalytic activity of the samples was studied by photocatalytic degradation of the aqueous solution of methylene blue (MB) under sunlight. The presence of Ag in polypyrrole (Ppy) enhanced its photocatalytic activity with respect to the reported values which further increased on increasing the silver concentration. 2021 Elsevier B.V. -
Polypyrrole/ silver/graphene ternary nanocomposite synthesis and study on photocatalytic property in degrading Congo red dye under visible light
In this report, a simple chemical synthesis of polypyrrole/silver/graphene (Ppy/Ag/Gr) ternary nanocomposites with varying concentrations of graphene are described. The XRD spectra of the samples polypyrrole/silver (Ppy/Ag) and Ppy/Ag/Gr show all the peaks of the face-centered cubic structure of silver. A broad peak between 10 and 20 and a peak at 26.7 corresponds to Ppy and graphene respectively. Using FTIR, and UVVis. spectroscopies the interaction between polypyrrole, silver, and graphene were studied. In our work, we explored the photocatalytic property of the synthesised samples by using them to degrade the aqueous solution of a cancer-causing dye, Congo red. The percentage degradation of Congo red dye using the sample Ppy/Ag/Gr (0.5 wt.%) is obtained as 96% and the reaction rate calculated is 0.162/min., greater than that of Ppy/Ag and Ppy/Gr binary composites. Thus, the addition of the optimum concentration of graphene into Ppy/Ag enhanced its photocatalytic property. The BET analysis shows an increased surface area for the sample Ppy/Ag/Gr (0.5 wt.%) and the reason for the enhancement of photocatalysis with this sample is confirmed since it is a surface-dependent property. The biodegradability of the dye solution was investigated by Chemical Oxygen Demand (COD) analysis and the COD value was reduced from 432 mg/L to 216 mg/L after 20 min of irradiation of light. 2023 -
Populism and the question of sovereignty in democracy with special reference to India
The sovereign manner of decision-making in a democracy is reckoned extremely crucial to stable governance. It is unfortunate, therefore, if the question of sovereignty acquires public attention predominantly in the wake of totalitarianist tendencies. It is the case now that with the emergence of several populist voices and nationalist sentiments, contemporary democracies actively debate the question of democratic sovereignty. This article is a critique of the complacency arising out of what is often wrongly perceived as the reassurances of the letter, or for that matter the spirit, of the constitutions of liberal democracies. Regardless of whether populism is traced within the electoral context or outside of it, the question of sovereignty offers a vantage point for understanding it from a theoretical perspective. In this regard, the article utilises the insightful yet contrasting notions of democratic sovereignty put forward by the philosophers Giorgio Agamben and Jacques Derrida. They approach the question of sovereignty from historical and/or linguistic points of view, illuminating the notions of sharing, sovereign violence and its overarching theological underpinnings. The articles findings, purposes and effects are meant to be educational and cultural in the first place. It employs, for the purpose of exemplification, a commentary on the Indian democratic scene. The Author(s), under exclusive licence to Springer Nature Switzerland AG 2024. -
Populist Protests and the Dynamic Zero-COVID Policy: (Re)emerging Pragmatic Populism in China
Populist protests in the Peoples Republic of China (PRC) have recently emerged as a reaction against the Chinese authorities stringent measures under its dynamic zero-COVID policy. Besides the vehement criticism and protests against the dynamic zero-COVID policy, during some protests, there have been ensuing calls across the country for President Xi Jinping to step down. The article argues that this scenario can further deteriorate the overall political legitimacy of the Communist Party of China on a long-term basis. According to the article, the protests indicate the re-emergence of populism in the PRC, which incidentally and historically has parallels to the protests at Tiananmen Square, and the 1919 May Fourth Movement. The article theorizes John Deweys concept of pragmatic populism and the aspect of protests during the period, which inherently provides many ideational and relational facets with the recent protests in China. 2023 Jawaharlal Nehru University. -
Porous 3D Printed System for Synergistic Tandem Water Cleaning-Energy Generation
Non-availability of fresh water is the dire consequence of rapid industrialization and the unregulated discharge of industrial effluents. In an attempt to recover water from highly contaminated industrial wastewater, researchers have relied on developing various materials that can treat polluted water efficiently and sustainably. 3D printed materials have proved to be an emerging technology in water treatment. 2Dmaterials have recently enhanced filter technology due to their morphological properties. This study focuses on removing salinity and organic dyes utilizing 2DGadolinium telluride (Gd2Te3) coated 3D printed (2D@3DP) complex architecture. The 2D@3DP structure can potentially increase the contact time of adsorbed saline water due to its complex architecture and can remove ?52% salinity from brackish water. Furthermore, methylene blue (MB) and Methyl Orange (MO) removal efficiencies are ?69% and 45%, respectively. Spectroscopic and microscopic results confirm the adsorption of negatively charged chlorine ions on a positively charged 2D surface. The removal of bleaching powder is also tested for real-life applications, and ?20% of the bleaching powder is adsorbed. Moreover, the 2D@3DP device exhibits an electrical signal due to impinging sodium chloride droplets from different heights, making it a sustainable solution to address water pollution. 2023 Wiley-VCH GmbH. -
Porous carbon nanoparticles dispersed nematic liquid crystal: influence of the particle size on electro-optical and dielectric parameters
Porous carbon nanoparticles (PCNPs) of four different sizes (~180nm, ~51nm, ~41 and ~25nm) were dispersed into a nematic liquid crystal (NLC) in 0.25wt% concentration. PCNPs were derived from biowaste materials and pyrolysed at elevated temperatures to get the porous structure. Polarising optical microscopic observations were carried out in dark and bright states on both the pure NLC as well as NLC-PCNPs composites. Homogeneous alignment was well maintained in all the composites except the one with the highest sized (~180nm) PCNPs. Birefringence, relative permittivity and dielectric anisotropy, increases as the size of the PCNPs is decreased in the composites. The threshold voltage was also found to decrease with the decrease in the size of the PCNPs. Such investigations may be useful for the fabrication of display devices such as flat panel displays (FPDs) and phase shifters. 2021 Informa UK Limited, trading as Taylor & Francis Group. -
Porous carbons derived from Arecanut seeds by direct pyrolysis for efficient CO2 capture
In this report, we demonstrate the preparation of a series of carbon nanospheres (CNSs) with high surface area and tunable sizes from natural bioresource, Arecanut kernels, by using direct pyrolysis. This method offers a convenient approach to induce porosity in the synthesized carbons without the need for an activating agent. The textural parameters including the specific surface area, pore volume, and pore size can be controlled by the simple adjustment of the carbonization temperature from 700 to 1000C. The CNSs prepared at 700C showed a low specific surface area, whereas the higher carbonization temperatures (8001000C) supported the rise in specific surface area of the products (433.61001.4 m2/g). The carbon, hydrogen, and nitrogen (CHN) analysis revealed that the CNSs exhibited a high purity with the carbon percentage ranging between 96 and 99%. The synthesized materials were tested as adsorbents for CO2 gas, and it was found that the CNSs with the highest specific surface area of 1001.4 m2/g registered the CO2 adsorption capacity of 14.1 mmol/g at 0C and 30 bar, which is a reasonably high value among reported porous carbons prepared without activation. This value of CO2 adsorption also stands above the activated carbon and multiwalled carbon nanotubes. The excellent CO2 adsorption capability of these adsorbents along with their low-cost synthesis offers a feasible pathway for designing such materials for other applications as well. 2021, Qatar University and Springer Nature Switzerland AG. -
Portrait segmentation using ensemble of heterogeneous deep-learning models
Image segmentation plays a central role in a broad range of applications, such as medical image analysis, autonomous vehicles, video surveillance and augmented reality. Portrait segmenta-tion, which is a subset of semantic image segmentation, is widely used as a preprocessing step in multiple applications such as security systems, entertainment applications, video conferences, etc. A substantial amount of deep learning-based portrait segmentation approaches have been developed, since the performance and accuracy of semantic image segmentation have improved significantly due to the recent introduction of deep learning technology. However, these approaches are limited to a single portrait segmentation model. In this paper, we propose a novel approach using an ensemble method by combining multiple heterogeneous deep-learning based portrait segmentation models to improve the segmentation performance. The Two-Models ensemble and Three-Models ensemble, using a simple soft voting method and weighted soft voting method, were experimented. Intersection over Union (IoU) metric, IoU standard deviation and false prediction rate were used to evaluate the performance. Cost efficiency was calculated to analyze the efficiency of segmentation. The experiment results show that the proposed ensemble approach can perform with higher accuracy and lower errors than single deep-learning-based portrait segmentation models. The results also show that the ensemble of deep-learning models typically increases the use of memory and computing power, although it also shows that the ensemble of deep-learning models can perform more efficiently than a single model with higher accuracy using less memory and less computing power. 2021 by the authors. Licensee MDPI, Basel, Switzerland. -
Portraying the Other in Textbooks and Movies: The Mental Borders and Their Implications for IndiaPakistan Relations
Borders have been traditionally known just as physical cartographic boundaries on maps. However, the epistemological and ontological underpinnings of Border Studies have witnessed constant evolution in the past century. This has brought to the fore the importance of mental borders along with the physical borders. When it comes to a region like South Asia, the lack of regional integration is conspicuous. One of the reasons for this is the existence of mental borders along with rigid physical borders. The paper seeks to understand the process of creation of mental borders between the two South Asian neighbours by probing it from the point of view of school textbooks and cinematic narrative. School textbooks are the most fundamental building blocks of knowledge in any society. Analysis of these texts brings forward the metaphysical construction of mental borders at a very early stage. Subsequently, cinema as a mode of popular culture is an effective tool in order to understand social phenomena from peoples perspective. Here, the process of meaning creation is largely embedded in linguistics and is derived from peoples experiences. The deconstruction of these data sources leads to the understanding of the process of mental border formation. 2019, 2019 Association for Borderlands Studies. -
Positive ageing: self-compassion as a mediator between forgiveness and psychological well-being in older adults
Purpose: Positive aging aims to promote the physical health and psychological well-being of older adults for them to age successfully. Under the domain of positive aging, this study aims to explore the mediating role of self-compassion between forgiveness and psychological well-being in older adults. Design/methodology/approach: It was based on a quantitative research design, with a sample of 250 individuals within the age group of 6075 years. Data was collected using Self-compassion Scale (2003), Heartland Forgiveness Scale (2005) and Psychological Well-being Scale. Analysis was performed using Pearsons correlation, linear regression, followed by the generalised linear model of mediation. Findings: The results revealed a significant (p ? 0.001), high and positive correlation between self-compassion and forgiveness (r = 0.821), forgiveness and psychological well-being (r = 0.852) and self-compassion and psychological well-being (r = 0.802). Linear regression suggested that self-compassion and forgiveness are significant (p ? 0.001) predictors of psychological well-being, causing a variance of 75.6%. Mediation revealed significant (p ? 0.001) direct, indirect and total effect between the variables, showing that self-compassion partially mediates the relationship between forgiveness and psychological well-being. Research limitations/implications: The findings provide valuable insights on how fostering self-compassion along with forgiveness can improve psychological well-being among the elderly, however, research on additional variables, drawing comparisons between gender, economic status and clinical populations can be further explored. Nevertheless, this study can be used to develop interventions and therapeutic techniques to enhance self-compassion and forgiveness to improve psychological well-being among older adults. Originality/value: As per the best knowledge of the researcher, this work is original as it is a primary research and no data has been collected of a similar nature from the participants. 2024, Emerald Publishing Limited. -
Positive psychology in individual wellness: a thematic illustration of drama as a therapeutic framework in identity transformation
Purpose: The language of participative theatre can be considered immersive in the treatment of its dialectics where participants engage fully with their dichotomies and value systems through physical and psychological exploratory processes as they commit themselves to transformation. Design/methodology/approach: The use of drama as an intervention for challenging recurring mental models of oppressive narratives is used extensively in experiential psychotherapy and as a socio-psychological integrative tool. This experiential methodology allows for an organic development and expression of themes and motifs by encouraging a participant to develop a deeper awareness of how he/she interprets their identity and that of the community in which they function. Findings: This paper aims to review the implications of applying drama-based interventions as positive psychotherapeutic devices to facilitate self-reflection and active-constructive responding in enabling a rendering of positive patterns of thought and purposeful movement towards emotional and physical well-being. Practical implications: Research on the principles of positive psychology suggests that positive emotions lead to therapeutic change. Nurturing positive emotions which are immanent in spirituality, creativity and optimistic perseverance through autonomy and self-regulation enable individual potential to come to meaningful fruition. Originality/value: The paper conceptualizes psychodrama as a framing technique in enabling reflexive action in identity transformation and well-being. 2024, Emerald Publishing Limited. -
Positive side effects of the Covid-19 pandemic on environmental sustainability: evidence from the quadrilateral security dialogue countries
Purpose: The eruption of coronavirus disease 2019 (COVID-19) has pointedly subdued global economic growth and producing significant impact on environment. As a medicine or a treatment is yet available at mass level, social distancing and lockdown is expected the key way to avert it. Some outcome advocates that lockdown strategies considered to reduce air pollution by curtailing the carbon emission. Current investigation strives to affirm the impact of lockdown and social distancing policy due to covid-19 outbreak on environmental pollution in the QUAD nations. Design/methodology/approach: To calibrate the social movement of public, six indicators such residential mobility, transit mobility, workplace mobility, grocery and pharmacy mobility, retail and recreation mobility and park mobility have been deliberated. The data of human mobility have been gathered from the Google mobility database. To achieve the relevant objectives, current pragmatic analysis exerts a panel autoregressive distributed lag model (ARDL)-based framework using the pooled mean-group (PMG) estimator, proposed by Pesaran and Shin (1999), Pesaran and Smith (1995). Findings: The outcome reveals that in the long-run public mobility change significantly impact the pollutants such as PM2.5 and nitrogen dioxide; however, it does not lead to any changes on ozone level. As per as short run outcome is concerned, the consequence unearths country wise heterogeneous impact of different indicators of public mobility on the air pollution. Research limitations/implications: The ultimate inferences of the above findings have been made merely on the basis of examination of QUAD economies; however, comprehensive studies can be performed by considering modern economies simultaneously. Additionally, finding could be constraint in terms of data; for instance, Google data used may not suitably signify real public mobility changes. Originality/value: A considerable amount of investigation explores the impact of covid-19 on environmental consequences by taking carbon emission as a relevant indicator of environmental pollution. Hence, the present pragmatic investigation attempts to advance the present discernment of the above subject in two inventive ways. Primarily, by investigating other components of environmental pollution such as nitrogen dioxide, PM2.5 and ozone, to reveal the impact of covid-19 outbreak on environmental pollution, as disregarded by the all preceding studies. Additionally, it makes a methodological contribution before integrating supplementary variables accompanying with ecological air pollution. Finally, the current research article provides an alternative and creative approach of modeling the impact of public mobility on environmental sustainability. 2021, Emerald Publishing Limited. -
Possibilities for the Flow of Water and Blood through a Graphene Layer in a Geometry Analogous to Human Arterioles: An Observational Study
Atherosclerosis and aneurysm are two non-communicable diseases that affect the human arterial network. The arterioles undergo dimensional changes that prominently influence the flow of oxygen and nutrients to distal organs and organ systems. Several studies have emerged discussing the various possibilities for the circumstances surrounding the existence of these pathologies. In the present work, we analyze the flow of blood across the stenosis and the aneurysmic sac in contrast with the flow of water to explore alterations in the flow characteristics caused by introduction of the graphene layer. We investigate the blood flow past the graphene layer with varying porosity. The study is undertaken to replace usage of a stent along a blocked artery by inserting a thin layer of graphene along the flow channel in the post-pathological section of the geometry. To explain the flow, a 2D mathematical model is constructed, and the validity and exclusivity of the models solution are examined. When the artery wall is assumed to be inelastic, the computation of the mathematical system is evaluated using a finite element method (FEM) solver. We define a new parameter called critical porosity (Formula presented.) to explore the flow possibilities through the graphene layer. The findings indicate that the flow pattern was adversely affected by the graphene layer that was added to the flow field. The negative impact on the flow could be due to the position of the graphene layer placed. The (Formula presented.) values for the flow of blood across healthy arteriole, stenosed arteriole, and aneurysmic arteriole segments were (Formula presented.) and (Formula presented.) respectively. The critical porosity values were achieved with precision in terms of linear errors (Formula presented.), (Formula presented.), and (Formula presented.), respectively. The consequences of the present study disclose various possible ways to utilize graphene and its compounds in the medical and clinical arena, with a prior exploration of the chemical properties of the compound. The idea and the methodology applied for the present study are novel as there have been no previous research works available in this direction of the research field. 2023 by the authors. -
Post listing IPO returns and performance in India: An empirical investigation
Objectives: (a) To analyse the performance of Indian IPOs in the short term. (b) To determine the significance of abnormal return of the IPOs. (c) To study the impact of over-subscription, profit after tax, promoters' holdings, issue price and market returns on IPO performance. Design/ Methodology/Approach: This research paper is based on empirical analysis. All the 52 IPO's listed in the NSE (National Stock Exchange, India) during the year 2018 to 2020 were considered for the study. The study is based on secondary data. The daily share price and Nifty-50 index value were taken from NSE website (www.nseindia.com) and other relevant data from red-herring prospectus of the respective company. The research / statistical tools used are: Market adjusted short run performance model, Wealth relative model, 't' test and regression analysis. Scope of the study: The scope of the study is limited to the IPO's listed only in the National Stock Exchange (NSE), India. Period of study: The study covers a period from January 2018 to December, 2020. Limitation of the study: The study considers only the influence of the external factors on the performance of IPOs. Findings: The average IPO return on the first trading day is 13.52%, ranging from -23.15% to 82.16% with standard deviation of 26.72%. The average IPO return on the third trading day was the highest and is found to be14.52%, ranging from -19.22% to 117.55% with standard deviation of 18.57%. The analysis reveals that the over subscription impacts the IPO performance and the other factors namely, issue price, Profit after Tax, market returns and promoters holdings do not influence IPO returns. Originality / Value: This is an original work that analyses the listing gain or loss and the post listing performance of IPO's in India and other factors that might influence the listing gain or loss. Copyright 2021. T. Ramesh Chandra Babu and Aaron Ethan Charles Dsouza. Distributed under Creative Commons Attribution 4.0 International CC-BY 4.0 -
Post-formalist explanation of academic achievement: Exploring the contribution of John Ogbu and Joe Kincheloe
The present paper attempts to interrogate the existing approach to understand academic achievement in the mainstream educational psychology. The paper explores the persistent question of "why academic achievement gap" in the modern society from the cultural ecological and postformalist framework of John Ogbu and Joe Kincheloe respectively. As mainstream educational psychology limits its scope in the narrowed individualistic lens, paper suggests that dominant identity based curriculum, pedagogy and knowledge may concretize the psychological categories unless revolutionary efforts are made to transcend the boundaries. Thus, paper adopts critical interdisciplinary framework, rejecting positivistic metatheory as an only relevant approach in educational psychology. 2016, De Gruyter Open Ltd. All rights reserved.