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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). -
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. -
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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. -
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. -
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. -
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. -
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. -
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. -
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 doped spray dried ceramic nano oxides for high capacity battery electrodes
Electric vehicles or portable electronic devices have come to rely heavily upon electrochemical devices, such as rechargeable batteries with optimum charge discharge characteristics, current ratings, charge-discharge rate (rate capability), cyclability etc. to perform under the expected service conditions. One of the goals of a rechargeable battery materials researcher is to fabricate materials to realize solid-state batteries with high reliability and lithium-air batteries with ultimate capacities. Most of the materials although possess high theoretical energy density values: invariably suffer from inferior cyclic performance. The performance of these batteries is guided by the electrodes within these devices which in turn depend upon the materials used to fabricate them. Chemical composition and its uniformity, consistency in microstructural features, and adequate choice of various layers that may be in the form of coatings to be overlaid on the base materials mostly comprised of ceramic oxides such as oxides of Li doped with niobates, manganates, vanadate etc. with carbon or graphene coated over layers to provide with the suitable interfacial conductivity as electrode materials in Li-ion batteries. The interfacial layers and the mechanism of interfacial phenomena encompassing the grains play a significant role in determining the performance. Optimum microstructure is obtained by choosing the right processing equipment and spray drying the composition in slurry form provides the most optimum solution. Further, spray drying offers high potential for a transfer from a lab scale technology to industrial level extrapolation. In this paper, nano graphene has been spray dried along with nano alumina grains in water media and polyvinyl alcohol binder to ascertain the free flowability, consistency in formation of graphene over layer on alumina grains as well as uniformity in graphene on alumina composition. The free flowing spray dried graphene coated alumina powders were analysed via SEM, EDS and XRD and results are presented. Additional information based on a review conducted on published information on most popular compositions in terms of electrode materials such as in Li-ion, sodium-ion etc have also been included. In the review section the rapidly increasing literature on spray drying of solutions and suspensions are also included. Published under licence by IOP Publishing Ltd. -
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Graphene and graphene enhanced nanomaterials from biological precursors synthesis characterization and proliferant applications
Graphene family materials with non-photocatalytic biocidal properties are highly sought after in the field of biomedicine and nanobiotechnology. But the applications of graphene-based materials were often hampered by their high production cost, low yield, non-renewable precursors, harmful processing newlinetechniques, etc. In this context, this study presented the successful usage of biomass materials as sustainable feedstock for the production of graphene derivatives. Five raw materials of biological origin namely, coconut shell, wood, sugarcane bagasse, Colocasia esculenta leaves and Nelumbo nucifera leaves, were investigated. The graphitized forms of the above materials were newlineused as precursors for the graphene nanomaterial synthesis. They were chemically oxidized and functionalized with tin oxide nanoparticles to form the composite. Nano-systems obtained using an identical chemical route from a universal source of carbon nanomaterials, namely carbon black, were also newlinestudied for the purpose of validation and comparison. The synthesis protocols adopted for the preparation of graphene-based materials were devoid of hazardous reducing agents or byproducts. The products obtained after each stage of treatment were characterized with the help of various spectroscopic and microscopic techniques. newlineEven though structural properties of all the precursors appeared to be broadly the same, a variation in their morphology and defect density was discerned. Various analyses revealed the formation of graphene oxide domains with distinct dimensions after the oxidative treatment. An increase in defect newlinedensity was also observed due to the intercalation of oxygen groups to the carbon layers. Post composite formation, a distribution of ultrafine tin oxide newlinenanoparticles on the graphene surface was observed. The distribution of oxygen newlinefunctionalities on the carbon backbone were found to play a major role in governing the dispersal of tin oxide particles during the nanocomposite formation. -
Graph theory in security, utility, aesthetics and affordability
The theory of Domination in graphs is used in security systems. Landscaping uses planarity and crossing number. In layout designs, hamiltoincity is regulalry used. Edge-weighted graphs and Max-Flow Min-Cut models are also discussed in this paper. 2023 Author(s). -
Graph Theory and Decomposition
The book Graph Theory and Decomposition covers major areas of the decomposition of graphs. It is a three-part reference book with nine chapters that is aimed at enthusiasts as well as research scholars. It comprehends historical evolution and basic terminologies, and it deliberates on decompositions into cyclic graphs, such as cycle, digraph, and K4-e decompositions. In addition to determining the pendant number of graphs, it has a discourse on decomposing a graph into acyclic graphs like general tree, path, and star decompositions. It summarises another recently developed decomposition technique, which decomposes the given graph into multiple types of subgraphs. Major conjectures on graph decompositions are elaborately discussed. It alludes to a comprehensive bibliography that includes over 500 monographs and journal articles. It includes more than 500 theorems, around 100 definitions, 56 conjectures, 40 open problems, and an algorithm. The index section facilitates easy access to definitions, major conjectures, and named theorems. Thus, the book Graph Theory and Decomposition will be a great asset, we hope, in the field of decompositions of graphs and will serve as a reference book for all who are passionate about graph theory. 2024 Jomon Kottarathil, Sudev Naduvath and Joseph Varghese Kureethara. -
Grandparenting in Urban Bangalore, India: Support and Involvement From the Standpoint of Young Adult University Students
A variety of caregivers, including grandparents, help raise children. Among grandparents, most Western samples evidence a matrilateral (i.e., mothers kin) bias in caregiving, and many studies show more positive impacts and stronger relationships with grandmothers than grandfathers. The aim of the present study is to test competing hypotheses about a potential laterality bias and explore contrasts between grandmothers and grandfathers in a sample of urban young adult university students in Bangalore, India. A sample of 377 (252 women) relatively mobile and high socioeconomic status individuals 17 to 25 years of age completed a survey consisting of sociodemographic and grandparenting questions. Results reveal generally little evidence of either a patrilateral or matrilateral bias, though findings varied for some outcomes. As illustrations, there were no differences in residential proximity or the most recent time when a participant saw matrilateral or patrilateral grandparents, whereas maternal grandmothers were more approving of ones choice of a life partner than were paternal grandmothers. In inductively coded responses to an open-ended item about the roles of grandparents, maternal grandmothers were more often identified as guides and less often deemed non-significant than paternal grandmothers, while paternal grandfathers were less often viewed as guardians and more often noted for their influence compared with maternal grandparents. Findings also revealed differences between grandmothers and grandfathers, such as grandmothers playing more prominent roles in community and religious festivals. Findings are interpreted within changing residential, work, education, and family dynamics in urban India as well as a primary importance on parents relative to grandparents. The Author(s) 2019. -
Grain-growth engineering and mechanical properties of physical-vapour-deposited InSe platelets
The present work demonstrates a novel use of physical vapour deposition for grain-growth engineering by optimizing supersaturation, which led to the evolution of stoichiometric indium monoselenide crystals, employing a custom-fabricated dual-zone furnace. The growth zone was kept at a constant temperature for different experimental runs (673-883K), while the source zone was kept at a stable temperature of 1123K. In this way, the temperature difference ?T = 240-450K resulted in a significant increase of the mass transport between the zones so as to accomplish bulk crystallization. At comparatively low supersaturation (?T = 240K), the presence of nodules and flakes was observed. When ?T = 250K, multiple grains were formed owing to temperature asymmetry at the rough vapour-solid interface. A further increase in supersaturation (?T = 330K) facilitated polyhedral grain growth, with distinct grain boundaries. A subsequent increment in ?T (400K) led to evolution of the polycrystalline morphology to well developed hexagonal platelets owing to adsorption of atoms on surface steps and kinks in accordance with the leading-edge growth mechanism. Energy-dispersive analysis by X-rays and X-ray diffraction experiments were carried out to confirm the structure and phase of crystals. Microindentation studies were done to assess the hardness and mechanical stability of the as-grown crystals in response to external loads in order to explore their suitability for solar cell applications. The investigations of bulk vapour phase transport, morphology and strengthening of InSe platelets provide pathways for the production of crystalline textures with versatile properties. International Union of Crystallography 2017. -
GRAFFITI AS AN ART FORM USED IN MUSIC VIDEOS OF THE BAND COLDPLAY
The study is based on the analysis of the content of two videos in the popular British band - Coldplay. The two songs taken into account are ??Every Teardrop is a Waterfall and ??Hurts like Heaven. The visual content in these songs involves a lot of graffiti art which complement the wordings of the song and go along with the beats of the music. To gain more knowledge on the visual element used in videos and find out the reason for the use of the elements in these videos, to come to a conclusion which explains the audio and video of the song by the band and also to understand how it enhances the feel of the song in a better way, the researcher goes into detail and explains the significance and use of the elements (visuals, lyrics) in the songs ??Every Teardrop is a Waterfall and ??Hurts like Heaven by Coldplay with the aid of the required research methods. The method used to study Graffiti as an art form used in music videos of the popular band Coldplay is Qualitative method which helps in getting a detailed conclusion. The researcher adopts an in-depth analysis of the songs and their visual content (graffiti art). The study is validated with the help of experts opinions through interviews and secondary data like books, journals and online material. After the analysis of the music videos with the help of expert opinions, it is interpreted to come to specific findings. Use of journals, books and online material provide facts about the origin and development of the types of music, graffiti art and visuals. This leads to a better understanding of concepts involved in the study and bring in more credibility. -
Grading of Red Chilli, Cardamom and Coriander Using Image Processing
Indian cuisine is known for its wide range of spices. Spices are known as the heart and soul of Indian food. Traditionally, categories are identified based on certain chemical technology or with the help of senses gifted to mankind. In this paper, an image processing technique used to extract multiple features is presented to determine the various categories of spices consumed. This proposed work uses different varieties of common Indian spices such as Capsicum annuum (dry red chilli), Elettaria cardamomum (cardamom) and Coriandrum Sativum (coriander). While creating the image dataset, different categories of all spices were taken from southern region of India. Features are extracted from the manually created image dataset, which forms the base for classification. The result obtained using Multilayer Perceptron (MLP), Naive Bayes and Random Forest classifier is found to be optimal. 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. -
Grading of facial emotions using multimodal approach /
Patent Number: 202141020173, Applicant: Mr Praveen Kulkarni.
Emotion analysis is an area which is been widely used in forensic crime detection domain, mentoring device for depressed students, psychologically affected patient treatment. Although significant work has been done in this area, the current system helps only in identifying the emotions but not in identifying the level of emotions like whether an individual is truly happy/sad or pretending to be happy/sad.