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Graphene Nanotechnology for Renewable Energy Systems
The high degree of mechanical, electrical, and thermal conductivity of graphene enables its application in the renewable energy sector. Graphene plays a vital role in diodes, photovoltaic cells, supercapacitors, batteries, and full cells applications and it enhances the existing efficiency in a tremendous way. The addition of graphene can do tremendous effects on all kinds of inorganic and organic materials for solar cells. In the supercapacitor domain, graphene plays a vital role to provide a large surface which can be useful for energy storage applications. The hybrid supercapacitor and battery trends in research and technology have been discussed. The electrical vehicles and green applications need and accomplishments of graphene and its derivatives have also been described. 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. -
Graphene quantum dots: Promising catalysts for electrocatalytic water splitting
In recent times, graphene quantum dots have attracted attention from both academia and industry due to their low cost, non-toxicity, abundance, inertness, stability, photoluminescence, and ease of functionalization. Graphene quantum dots are doped with heteroatoms and modified structurally with metals/metal oxides to form composites that find immense application in catalysis. Electrocatalytic water splitting is an energy efficient route for oxygen evolution, hydrogen evolution, and oxygen reduction reactions. Graphene quantum dots based composites have been extensively employed for electrocatalytic water splitting applications, with remarkable results. This chapter focuses on electrocatalytic applications of modified graphene quantum dots in water splitting. 2024 Nova Science Publishers, Inc. All rights reserved. -
GrapheneLiquid Crystal Synergy: Advancing Sensor Technologies across Multiple Domains
This review explores the integration of graphene and liquid crystals to advance sensor technologies across multiple domains, with a focus on recent developments in thermal and infrared sensing, flexible actuators, chemical and biological detection, and environmental monitoring systems. The synergy between graphenes exceptional electrical, optical, and thermal properties and the dynamic behavior of liquid crystals leads to sensors with significantly enhanced sensitivity, selectivity, and versatility. Notable contributions of this review include highlighting key advancements such as graphene-doped liquid crystal IR detectors, shape-memory polymers for flexible actuators, and composite hydrogels for environmental pollutant detection. Additionally, this review addresses ongoing challenges in scalability and integration, providing insights into current research efforts aimed at overcoming these obstacles. The potential for multi-modal sensing, self-powered devices, and AI integration is discussed, suggesting a transformative impact of these composite sensors on various sectors, including health, environmental monitoring, and technology. This review demonstrates how the fusion of graphene and liquid crystals is pushing the boundaries of sensor technology, offering more sensitive, adaptable, and innovative solutions to global challenges. 2024 by the authors. -
Graphitic carbon nitride (GCN) for solar cell applications
There is an eminent global energy crisis and photovoltaics as one of the primary renewable energy sources is playing an important part in offsetting the dependency on fossil fuels. Current solar cells technology is dominated by silicon, and researchers are trying to replace it with organic and nanocrystalline semiconducting materials. Graphitic carbon nitride (g-C3N4, GCN) has gained interest as a visible light driven photocatalyst with a unique 2D structure, excellent chemical stability and tunable electronic structure along with attractive optoelectronic properties. Pure GCN suffers from low surface area and rapid recombination of photo-generated electron-hole pairs resulting in low photovoltaic and photocatalytic activity and hence modification by doping with other atoms is required. Photocatalytic applications of GCN based nanomaterials for water splitting, hydrogen production, CO2 reduction and pollutant degradation has been extensively investigated and systematically reviewed. However, their applications as energy storage has been explored recently and there is a lack of comprehensive review that systematically summarizes the application of GCN and GCN-based heterostructures for solar cell applications. Heterojunctions with superior light absorption and appropriate conduction band and valence band alignment is a promising approach for the applications in efficient environmental remediation and solar energy storage. This critical review summarizes the synthesis and advances of GCN nanocomposites modified with semiconductors (TiO2, ZnO), bismuth titanate, strontium titanate and rare earth metals for solar cell applications. GCN-based heterostructures with perovskite and polymer based materials are also presented. The characteristics and transfer mechanism within the various heterojunctions is also reviewed and presented. The review ends with a summary and some perspectives on the challenges and new directions in exploring GCN-based advanced nanomaterials particularly towards photovoltaics and energy storage applications. 2022 Elsevier Inc. All rights reserved. -
Graphitization of coal by bio-solubilization: Structure probe by Raman spectroscopy
Raman spectra of two coal samples of different rank have been examined with Raman spectrometer operating at an excitation wavelength of 514.5 nm. Raman studies manifested the presence of G band conforming the first order scattering of E2g mode. The sp3 domains at about 1355 cm-1 (D band) is an evidence to edge planes and disordered structures. Analysis by curve fitting the first order spectrum justified the presence of G, D1, D2, D3 and D4 bands. The integrated intensity ratio IG/ID? is found to be 3.66 and 5.8 while the ID/ID? ratio is estimated to be about 3 and 4.9 for bituminous and sub-bituminous coal, respectively indicating on-site and hopping defect in the graphene layers. The 2D band is fitted with multiple Lorentian profile has 4 peaks, the intense G?, G?, D + D? and 2D? band at 2445, 2690, 2925 and 3160 cm-1. From the second order spectrum, formation of about 6-8 stacked graphene layers is observed in sub-bitumionus coal. -
Graphs Defined on Rings: A Review
The study on graphs emerging from different algebraic structures such as groups, rings, fields, vector spaces, etc. is a prominent area of research in mathematics, as algebra and graph theory are two mathematical fields that focus on creating and analysing structures. There are numerous studies linking algebraic structures and graphs, which began with the introduction of Cayley graphs of groups. Several algebraic graphs have been defined on rings, a fast-growing area in the literature. In this article, we systematically review the literature on some variants of Cayley graphs that are defined on rings and highlight the properties and characteristics of such graphs, to showcase the research in this area. 2023 by the authors. -
Graphs Emerging from Finite Dimensional Vector Spaces
A vector space over a field is defined as a collection closed under finite vector addition and scalar multiplication. Over the course of time, researchers have delved into exploring the intricate relationships between existing algebraic structures and graphs. This exploration led to the emergence of a distinctive class of graphs derived from vector spaces, following investigations into graphs originating from groups and rings. This thesis undertakes a thorough examination of a well-established algebraic structure known as the non-zero component graph of a finite-dimensional vector space over finite fields. Expanding on this, the thesis introduces the concept of orthogonal component graphs over finitedimensional vector spaces with a particular emphasis on the field Zp. The non-zero component graph of a finite-dimensional vector space over a newlinefinite field is a graph where vertices represent all possible non-zero vectors in newlinethe vector space. Vertices in the graph are made adjacent if they share a common basis vector in their linear combination. The thesis explores a variety of properties relating to distances, domination, and connectivity. Furthermore, it conducts in-depth study of coloring, color connections, topological indices, and centrality-based sensitivity specifically for non-zero component graphs. The concept of orthogonality among vectors in the vector space paves the way for a novel algebraic graph structure the orthogonal component graph. In this graph, vertices represent all possible non-zero vectors in the vector space, and adjacent vertices correspond to orthogonal vectors. The study extends to determining the properties of the orthogonal component graph, particularly in the newlinecontext of the field Z p. Additionally, it characterises the relationship between newlinenon-zero component graphs and orthogonal component graphs. In the latter chapters, the concept of non-zero component signed graphs is introduced and thoroughly discussed. -
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Graphs on groups in terms of the order of elements: A review
Two mathematical fields that concentrate on creating and analyzing structures are algebra and graph theory. There are numerous studies linking algebraic structures like groups, rings, fields and vector spaces with graph theory. Several algebraic graphs have been defined based on the properties of the order of the group and its elements. In this paper, we systematically review the literature on such graphs to understand the research dynamics in the field. 2024 World Scientific Publishing Company. -
Graphs with large diameter and their two distance forcing number
For a given simple graph G = (V,E), the two distance forcing number Z2d (G) is defined as the minimum cardinality among all Z2d-sets in G. This paper examine about Z2d (G) of some graphs with large diameter. Also we determine the 2-distance forcing number of some complement graphs. 2021 the author(s). -
Gratitude as a path to human prosperity during adverse circumstances: a narrative review
Although each person faces their own share of challenges, it is their individual perception and responses to these difficulties that determine how they are affected by them. In this paper we investigate the association between gratitude and human prosperity including the underlying mechanism that helps people thrive during trying circumstances. We survey the literature, examining how gratitude enables people to prosper amidst adversity and employ a narrative style to present these unique characteristics. This review suggests that gratitude enhances coping abilities, such as meaning-focused coping and positive reframing, which foster positive emotions and augment personal resources like resilience, perseverance, and social bonds. These elements, in turn, may possibly explain the association between gratitude and human prosperity during dire circumstances. 2023 Informa UK Limited, trading as Taylor & Francis Group. -
Gravity modulation effect on ferromagnetic convection in a Darcy-Brinkman layer of porous medium
The influence of a timedependent body force on the threshold of convective instability in a magnetic fluid filled horizontal porous layer is investigated. The gravity modulation effect is treated by employing a perturbation method. The correction Rayleigh number is computedas a function of the modulation frequency, porous and magnetic parameters. It is expounded that, for small and reasonable values of the modulation frequency, gravity modulation and magnetic mechanism have opposing influence on the stability. The study further explicates that, when the gravity modulation frequency increases beyond all bounds, manifestation of the disappearance of the magnetic and porous medium effects on the stability is highly likely. Published under licence by IOP Publishing Ltd. -
Gravity modulation effect on ferromagnetic convection in a Darcy-Brinkman layer of porous medium /
International Conference On Applied And Computational Mathematics, Vol.1139, pp.1-10 -
Gravity-modulated RayleighBard convection in a Newtonian liquid bounded by rigidfree boundaries: a comparative study with other boundary conditions
Effect of different boundaries on the gravity-modulated RayleighBard convection has been investigated with an emphasis on rigidfree boundaries. Small-amplitude and large-amplitude modulations are studied using the linear stability analysis. The modified Venezian approach is used to study small-amplitude modulations using different modes of perturbations and the superposition principle. The existence of subharmonic motions for the case of large-amplitude modulations was explored using the Mathieu equation arising from the linear stability analysis. Floquet theory was used together with Hills infinite determinant method to compute the critical Rayleigh number for the case of large-amplitude modulations. Weakly non-linear analysis is performed leading to the cubic StuartLandau equation from the Lorenz system. Heat transport was quantified using the Nusselt number and the mean Nusselt numbers for different amplitudes and frequencies. It was found that gravity modulation has, in general, a stabilizing effect on the convection process in all three boundary types, and the heat transport was found to be an increasing function of amplitude. Another important outcome of the study is that the critical Rayleigh number for the onset of convection for rigidfree boundaries lies between those of the corresponding values of the freefree and rigidrigid boundaries in the case of both harmonic and subharmonic motions which could be exploited in controlling convection. 2023, The Author(s), under exclusive licence to Springer Nature B.V. -
Gray Level Co-occurrence Matrix based Fully Convolutional Neural Network Model for Pneumonia Detection
This study presents a new method to improve the detection ability of a convolutional neural network (CNN) in pneumonia detection using chest X-ray images. Using Gray-Level Co-occurrence Matrix (GLCM) analysis, additional channels are added to the original image data provided by Guangzhou Children's Hospital in Guangzhou, China. The main goal is to design a lightweight, fully convolution network and increase its available information using GLCM. Performance analysis is performed on the new CNN model and GLCM-enhanced CNN model, and results are compared with Transfer Learning approaches. Various evaluation metrics, including accuracy, precision, recall, F1 score, and AUC-ROC, are used to evaluate the improved analysis performance of CNN. The results showed a significant increase in the ability of the model to detect pneumonia, with an accuracy of 99.57%. In addition, the study evaluates the descriptive properties of the CNN model by analyzing its decision process using Grad-CAM. 2024, J.J. Strossmayer University of Osijek, Faculty of Electrical Engineering, Computer Science and Information Technology. All rights reserved. -
Green accounting and its application: A study on reporting practices of environmental accounting in India
Green Accounting is an important device for understanding the role of business ventures in the economy towards environmental security and welfare. It is a well-known term for environment and natural resources accounting. Many companies all over the world have initiated the practices of making environmental disclosures in their annual reports. However, these practices are still largely voluntary in nature. The objective of this research paper is to study the environment-related disclosures of companies taken from Nifty 50 based on the summary of Global Reporting Standards. Content Analysis, both sector-wise and keyword-wise is used on the annual reports of 29 sample companies using MAXQDA software. A high count of the formulated keywords is observed in some relevant sectors of Energy, Cement and Metals. 2022 Inderscience Enterprises Ltd. -
Green and Sustainable Software Model for IT Enterprises
The present study is based on developing a Green and Sustainable software because in the present-day computing devices are used for all kinds of purposes and they consume a lot of energy to perform these services. The ICT sector itself consumes a lot of energy so there is a need to think of alternatives that can reduce the level of energy consumption, thus, green ICT practice can be a good option. There is, however, a scarcity of researches that explains how the maintenance of green knowledge in ICT software development may be implemented. Since we recognize that software development process (SDL) plays an essential role in enabling the ICT community, uncontrolled green knowledge in developing software that would lead to the dilemma of failing to satisfy both the community's business and environmental requirements. Therefore, this research will concentrate on presenting a methodology applying an innovative model for managing the green software development and implementation. Keeping this concern in mind the present paper is going to provide a Green and Sustainable software model which can be used in green ICT practices and will be helpful in reducing the energy consumption used by computers. 2021 IEEE. -
Green Bonds Driving Sustainable Transition in Asian Economies: The Case of India
On September 25, 2015, 193 countries of the United Nations (UN) General Assembly, signed the 2030 Agenda to work towards attaining 17 Sustainable Development Goals (SDGs) and its associated 169 targets and 232 indicators. With one of the largest renewable energy programs, India is well-poised to be a role model for low-carbon transformation to other Asian countries. However, bridging the financing gap is critical to ensure that the country meets its SDG targets. Though the SDGs identified by the UN are broad-based and interdependent, for ease of analysis we have grouped them into five themes people, planet, prosperity, peace, and partnership based on existing UN models. This paper investigates the financing gap for green' projects linked to planet-related SDG targets in India. It builds an argument for utilizing green bonds as an instrument to bridge the gap. After establishing the potential of green bonds in raising the finance to meet India's planet-related SDG targets, we look at the current policy landscape and suggest recommendations for successful execution. The paper concludes that deepening of the corporate fixed income securities market and firming up guidelines in line with India's climate action plans are inevitable before green bonds can be considered a viable financing option. 2021. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (https://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. All rights reserved. -
Green Bonds: A Propitious Financial Instrument of Climate Finance
Green bonds are a comparatively recent investment mechanism for green initiatives and are perceived as the first line of climate change protection. The aim of the article is to decide if the issuing of a green bond is perceived to be good news for market players, and also to ascertain whether developing markets, relative to established markets, are more inclined towards green bonds to tackle climate change. The study used an international sample of recent green bond issues and illustrated the possible effects of the issuing of a green bond for the issuer. A sample of 392 green bonds released from 2017 to 2020 is included. Event study methodology is used to analyse investor response to green bond issuance. Over the years, emerging markets have been found to be keen on greening projects by green bonds, much in line with established markets. The findings suggest that on the day of issuance of the green bonds the stock market responds adversely and reacts positively after the day. Hence statistical technique is applied on different event windows to obtain the cumulative abnormal returns (CAR). Statistical analysis concludes that the market responds adversely to the issuing of a green bond. This influence is particularly evident in the first issuing of green bonds and in developing markets. This research shows that proposals of green debt transmit unfavourable knowledge about the issuing companies. These results are relevant only in the case of green bonds issued by listed firms. 2023 MDI. -
Green Data Centers: A Review of Current Trends and Practices
A green data center is a facility that makes use of eco-friendly techniques and technologies to lessen its carbon footprint and environmental impact. A data center can consume as much electricity as a small city and contains thousands of servers. These server farms require an enormous amount of processing power to operate, which presents numerous difficulties, including high energy costs, greenhouse gas emissions, backups, and recovery. This paper clarifies the various green data center best practices, including energy efficiency, cooling systems, renewable energy, sustainable building techniques, and carbon footprint. The need for green data centers in todays internet, commercial, financial, and business applications is also covered in the paper. The reality and myths of green data centers are alsoexamined. The paper delves into the metrics for each characteristic used to gauge how green and effective data centers are. The discussion has concluded with case studies of companies that have implemented green data centers. The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.