Browsing by Author "Sudhanshu Kumar"

Now showing 1 - 8 of 8

Avifaunal Diversity in Managed Urban Ecosystem: A Case Study of Banaras Hindu University, Varanasi
(Nicolaus Copernicus University, 2024) Rinku Singh; Amit Kumar Tiwari; Sudhanshu Kumar; Gopal Shankar Singh
University campuses are becoming important places for conducting a large number of studies on plant and animal taxa including avian diversity. However, a systematic study on the avian diversity in the Banaras Hindu University (BHU) campus (Asia's largest residential university campus) of Varanasi is still lacking. The present study deals with the species abundance, diversity and species richness of avian communities in the BHU campus. We conducted a bird survey in the BHU campus between 2019 and 2020. Employing line-transect method, a total of 141 bird species under 62 families were recorded from the study area. A rich diversity of species recorded indicates the importance of the university campuses in urbanized region to serve as a critical habitat for birds. To conserve this rich bird diversity of the campus, we suggest sustainable management of habitats through restoration of degraded habitats, reduction in habitat destruction, conservation awareness programmes and increased research on assessment of diversity. © 2024 Nicolaus Copernicus University. All rights reserved.
Biosynthesis of TiO2 nanostructures using Camellia sinensis extract (polyphenols) and investigation of their execution as photoanodes in photovoltaic device
(Elsevier B.V., 2024) Aman Kumar; Anamika Chaudhari; Sudhanshu Kumar; Suman Kushwaha
Titanium dioxide (TiO2) nanoparticles (NPs) are indeed widely recognized and utilized as one of the most prominent photoanode materials in dye-sensitized solar cells (DSSCs). Therefore continuous efforts have been made to improve the performance of TiO2 photoanodes in terms of light absorption, charge carrier mobility, and overall energy conversion efficiency. Green synthesis methods for the production of TiO2 NPs, including the use of plant-based reducing agents, have gained significant attention in recent years. These methods are considered environmental friendly alternatives to traditional physical and chemical synthesis methods, which often involve the use of hazardous chemicals and complex processes. Therefore, in this work, a variety of tea types, including green, white, black, oolong, pu-erh have been used to synthesize TiO2 NPs. The differences in the amount of phenolic compounds and caffeine in various tea varieties can influence the topology, structure, and composition of the as synthesized nanoparticles (NPs). The prepared TiO2 NPs were comprehensively characterized for particle size, morphology, purity, composition, crystalline nature, structural, electrochemical and photovoltaic capabilities. The as synthesized titanium oxide (TiO2) NPs were spherical in shape and particle sizes ranged from 10 to 20 nm with little agglomerations. For DSSC application, thin films of synthesized TiO2 NPs were prepared by making paste of TiO2 NPs with Triton-X and spread onto conducting substrate (FTO) with the help of glass rod and finally sintering for 1 h at 450 °C. The prepared TiO2 electrodes were dipped in the standard N719 dye solution (0.1 × 10−3 M) in acetonitrile medium overnight for complete adsorption. Overall efficiency = 3.0 %, JSC = 9.72 mA/cm2, VOC = 660 mV and FF = 0.46 was achieved with the DSSC made up with green tea mediated TiO2 NPs based photo anode. Due to high phenolic content and good reductive properties, TiO2 NPs prepared using green tea extract were highly crystalline in nature, have high surface area, high roughness factor, good stability which results in maximum dye loading and hence increase in the overall conversion efficiency. © 2024 Elsevier B.V.
Comparative study of natural and synthetic dyes in DSSCs: An experimental and computational approach
(Elsevier B.V., 2024) Aman Kumar; Anamika Chaudhari; Sudhanshu Kumar; Suman Kushwaha; Sudip Mandal
This study explores the natural and synthetic dyes as sensitizers for dye-sensitized solar cells (DSSCs). Anthocyanin dye extract (PG) from pomegranate (Punica granatum) fruit, betanin pigment (BR) from beetroot (Beta vulgaris), and the commercially available organic dye, Rose Bengal (RB), were investigated as sensitizers for DSSCs and their photovoltaic performances were recorded. Density functional theory (DFT) and time-dependent DFT (TD-DFT) studies have also been performed in order to get insight into the photophysical and photoelectrochemical properties. The overall efficiencies (η) of 0.34%, 0.30%, and 0.25% were obtained for the PG, BR, and RB dyes under 1 sun illumination, respectively. The results infer that PG dye would act as a promising photo-sensitizer for DSSCs as compared to BR and RB sensitizers, which may be due to better interaction between anthocyanin molecule of pomegranate extract and TiO2. © 2024 Elsevier B.V.
Participatory nature-driven urbanism: a pathway to achieving SDG-11 through community-led action
(Springer, 2025) Nazuk Bhasin; Sudhanshu Kumar; Gopal Shankar Singh
With escalating climate risks and environmental degradation, cities are struggling to meet the criteria of the United Nations Sustainable Development Goal 11 (SDG-11): Sustainable Cities and Communities. Conventionally, urban planning approaches have often overlooked community participation, traditional ecological knowledge, and the potential of nature-based solutions. This manuscript proposes that the Nature-Driven Urbanism (NDU) paradigm, centred around participatory governance and community-led ecological initiatives, be used as a transformative approach to help cities achieve SDG-11. Through an exploration of NDU principles and illustrative examples drawn from a variety of global urban contexts, this article examines how urban socio-ecological systems (USES) can flourish when local residents are at the core of decision-making. The review comprehensively demonstrates that integrating communities into decision-making processes through participatory NDU is crucial for cultivating USES that are more resilient to climate change, and are increasingly inclusive, liveable, and biodiverse. This critical shift from centralised, top-down urban planning towards decentralised community-based ecological governance models is therefore not merely an option but a strategic imperative for the future of urban sustainability. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2025.
Perceptions of impacts and management of invasive alien plants: a case study from Mirzapur, India
(Frontiers Media SA, 2023) Sudhanshu Kumar; Renu Meena; Amit Kumar Tiwari; Rinku Singh; Sanoj Kumar Patel; Gopal Shankar Singh
Invasive alien plants (IAPs) have become a serious threat to biodiversity, agriculture and socio-economic development. Several aspects, including the ecological and economic impacts of IAPs have been explored in the recent past, however, perceptions of ecosystem services (ES) and ecosystem disservices (EDS) have not been well studied. IAPs affect the lives of local people both positively (providing ES) and negatively (providing EDS). IAPs in this region have not been studied through the aspects of ES and EDS that integrate the views and perceptions of local communities. Keeping in view this research gap, the present study was conducted in the Mirzapur district (Uttar Pradesh, India) where IAPs are widely distributed. In five sites covering a rural to urban gradient with increasing distance from forest, we randomly selected 100 respondents–20 from each of the five sites for the survey. A semi-structured questionnaire was used to collect respondents’ perceptions on ES and EDS supplied by IAPs in their local habitats. The questionnaire was designed to obtain data on awareness and knowledge, perceptions of ES and EDS, attitudes toward management, and socio-demographic information. Results indicated that 95% of respondents were familiar with at least one of the 12 IAPs identified as being important in the region. Ipomea carnea and Stylosanthes hamata were the most and least frequently cited plants, respectively. Medical use and reduction in soil fertility were most perceived as ES and EDS, respectively. The value of Spearman’s rank correlation coefficient (Spearman’s ρ = 0.487, p > 0.05) indicates a non-significant correlation between ranks of ES and EDS cited by respondents. Older and less educated people were more aware of the impacts of IAPs. Uprooting was the most commonly used management practice to control the invasion of plant species. People’s attitudes toward the management of IAPs seem to indicate that they prefer to eradicate species that have direct harmful effects on human health and biodiversity. This study provides inputs for incorporating people’s perceptions into the control and management of IAPs in the forest region. Copyright © 2023 Kumar, Meena, Tiwari, Singh, Patel and Singh.
Socio-ecological Challenges and Adaptation Strategies of Farmers Towards Changing Climate in Vindhyan highlands, India
(Springer, 2025) Sanoj Kumar Patel; Anil Sharma; Anil Barla; Amit Kumar Tiwari; Rinku C. Singh; Sudhanshu Kumar; Gopal Shankar Singh
The Indian agriculture is highly vulnerable to climate change which adversely affects crop production and livelihood of farmers. The effect is more intensified in Vindhyan highlands, where prolong drought and high rate of poverty exist in depredation environment. In this context, present study conducted to explore farmers’ perception, attitude about climate change and adaptive capabilities. We undertook an interview schedules survey through structured questionnaire in Duddhi block of Sonbhadra district. A total of 400 households were selected in which 347 (86.75%) male and 53 (13.25%) female respondents have participated. The perception of farmers on climate change is presented in SI (severity index) which varies from 36% to 68.63%. The statement ‘rainy season decreases’ ranked first with SI (68.63%) followed by ‘temperature increases’ SI (66.06%). This investigation identified 17 types of adaptive practices which are frequently performed in the Vindhyan highlands. Based on the WAI (Weighted Average Index) score, crop diversification (2.0), cultivation of drought-adapted crop varieties (1.99), changing plantation calendar (1.95) were the most adopted practices. Multiple regression analysis between the socio-economic status of farmers and the adaptation practices, recorded a significant positive relationship with age (P < 0.01), family size (P < 0.05), education (P < 0.01), caste categories (P < 0.05) and livestock ownership (P < 0.01) of farmer. This study will be helpful in developing drought resilience farming practices for sustaining the livelihood of farmers and inform policy making. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2023.
Synthesis of TiO2 nanoparticles by green approach: Application as photoanode for dye-sensitized solar cells
(Elsevier Ltd, 2024) Anamika Chaudhari; Aman Kumar; Sudhanshu Kumar; Suman Kushwaha
Efficient photoanodes play a central role in the performance of dye-sensitized solar cells. Traditional methods for synthesizing TiO2 often involve chemical processes that can be expensive and environmentally harmful due to the use of toxic and hazardous substances. Therefore in this work, TiO2 nanoparticles (NPs) were synthesized using bio-inspired processing through a hydrothermal procedure using different concentrations of Aloe barbadensis miller leaves extract as the reducing and stabilizing agent. Scanning electron microscopy (SEM), UV–vis spectroscopy (UV), X-ray difraction (XRD), Raman Spectroscopy, transmission electron microscopy (TEM) and Brunauer–Emmett–Teller (BET) analysis were used to characterize as synthesized TiO2 NPs. DSSCs were fabricated employing the prepared TiO2 NPs as photoanodes, and their performance was assessed. DSSC generates JSC of 9.7 mA/cm2, VOC of 0.682 V and efficiency (η) of 4.3 % when 20 mL concentration of extract was used for the synthesis of TiO2 NPs and subsequently their photoanodes. © 2024 Elsevier Ltd
Thin-film fabrication techniques in dye-sensitized solar cells for energy harvesting
(wiley, 2024) Aman Kumar; Anamika Chaudhari; Sudhanshu Kumar; Suman Kushwaha; Sudip Mandal
From the last few decades, dye-sensitized solar cells (DSSCs) have emerged out as economical and reliable substitutes for energy source owing to their simple preparation, cheap cost, low toxicity, and competitive efficiency. The key components of DSSCs include the semiconducting thin film, sensitizer, redox couple, and counter electrode. The photoanode, which is made of a semiconducting thin film with a dye adsorbed on it, plays a crucial role in DSSCs, and its morphology depends on the deposition techniques used. Various established physical and chemical coating/deposition methods are promising for attaining high-quality thin films for DSSC fabrication. The morphology and particle size of the thin films strongly depend on the deposition techniques employed. Surface and interfacial effects significantly impact the whole performance of these films, leading to improved properties and characteristics compared to bulk materials. Highly functionalized thin films have their benefits when used as photoanodes in DSSCs, as the boosted functional properties of materials can be exploited at the nanoscale level. There are several techniques for depositing thin films, including physical, chemical, and colloidal routes. Some widely used methods include spray pyrolysis, sol-gel, plasma spray, electrophoretic deposition, screen printing, and dip coating. Vacuum deposition techniques such as magnetron sputtering and pulsed laser deposition are successfully established in the thinfilm coating industry due to the high quality and reproducibility of the fabricated thin films. While these techniques often require expensive equipment and complex experimental setups, they offer the advantage of producing thin and dense films. Colloidal, doctor blade, and dip coating techniques are advantageous because of their low cost and simplified experimental setup and equipment. These techniques produce thin films with controlled structures and particle size distributions. However, they may be prone to issues such as cracks, pores, or layer separation, which can be overcome by repeating the coating process several times intermittently. Sol-gel and slurry methods are extensively used to fabricate nanocrystalline thin films in DSSCs due to their lower cost than gas-phase methods. However, the meager stability of the precursors against hydrolysis remains a concern. The SILAR (successive ionic layer adsorption and reaction) method is another solution-based thin-film deposition technique, a modified version of chemical bath deposition. The resulting thin films exhibit improved grain structure orientation. In short, various deposition techniques are employed to fabricate thin films for DSSCs, each with its advantages and challenges. Researchers continue to explore and optimize these techniques/methods to improve the overall performance of DSSCs. © 2024 Scrivener Publishing LLC. All rights reserved.