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Analysis of students' preferences for teachers based on performance attributes in higher education
Faculty evaluation is widely used not only for the appraisal of their performance, but also for curriculum innovation and development. There are many techniques to perform faculty evaluation. But these techniques do not address all the factors essential for evaluating a faculty. These evaluations are subjective in nature and found to be controversial as students' expectations vary. This hinders the main motive of faculty evaluation. To overcome this problem, there is a need to identify a suitable method to perform faculty evaluation. In this paper, the Conjoint Analysis, a mathematical statistics technique is used to analyze the major aspects that the students are expecting from their faculty. This technique increases the fairness in the appraisal process so that teaching can be made fun and effective. This research is a novel attempt that applies conjoint analysis to identify the major aspects of teaching in students' perspective. The proposed idea can be adapted to any domain where the customers' choice is valued particularly in Cloud computing services. 2019 Mithula G P, Arokia Paul Rajan R. -
Adsorption and storage of hydrogen- A computational model approach
Due to the imperative global energy transition crisis, hydrogen storage and adsorption technologies are becoming popular with the growing hydrogen economy. Recently, complex hydrides have been one of the most reliable materials for storing and transporting hydrogen gas to various fuel cells to generate clean energy with zero carbon emissions. With the ever-increasing carbon emissions, it is necessary to substitute the current energy sources with green hydrogen-based efficient energy-integrated systems. Herein, we propose an input-output model that comprehends complex hydrides such as lithium and magnesium alanates, amides and borohydrides to predict, estimate, and directly analyse hydrogen storage and adsorption. A critical and thorough comparative analysis of the respective complex hydrides for hydrogen adsorption and storage is discussed, elucidating the storage applications in water bodies. Several industrial scale-up processes, economic analysis, and plant design of hydrogen storage and adsorption approaches are suggested through volumetric and gravimetric calculations. 2024 Elsevier Inc. -
Financial inclusion of rural sector: Imperative for sustainable economic growth of India
This research paper aimed to take a look on the present status of financial inclusion in the Indian economy, especially in the rural sector. It also suggested few measures to be taken by the government and banking sector to enhance the inclusion of deprived sections of our country in the financial ecosystem. The data was collected from various secondary sources to depict the present level of financial inclusion, primarily after the implementation of various government policies. The suggested measures mainly included financial literacy and awareness campaign to be implemented at the grass root level along with a robust infrastructure to increase the telephone and internet connectivity in the rural sector. The researchers also analysed that the financial inclusion of the rural sector is imperative for the sustainable economic growth of an agricultural driven economy like India. 2021 Ecological Society of India. All rights reserved. -
Rise of Populism in Northeast India: A Case of Assam
A blend of historical and contemporary forces has shaped populism in India. The Congress governments shortcomings (20042014), marked by dynastic politics and corruption, paved the way for the rise of populism, particularly under the Bharatiya Janata Party (BJP), which capitalized on anti?elite sentiment. Narendra Modis leadership, characterized by Hindu nationalism and a development agenda, has significantly altered Indias political landscape. This study focuses on the rise of populism in Northeast India, specifically in Assam, where populist movements and leaders have increasingly influenced the socio?political environment. It explores the socio?economic conditions and identity politics that have driven the growth of populist ideologies, often leading to the marginalization of ethnic minorities. By analyzing key political events, movements, and policies, the research seeks to uncover the root causes of populism in Assam and its impact on democracy, social cohesion, and regional stability. Employing a qualitative methodology that includes political speeches, media analysis, and empirical evidence, the study examines how political leaders in Assam have mobilized regional and ethnic sentiments for electoral gains, further exacerbating ethnic marginalization. The article aims to understand the catalysts and consequences of populist governance in Assam, offering insights into the broader trend of populism in Northeast India and its future trajectory. 2024 by the author(s). -
Mamaearth: from a mothers dilemma to a multi-crore brand
Learning outcomes: The case study has several objectives: to gauge the evaluation of the direct-to-consumer industry in the economy of India, to analyse the competition of the brands, to ascertain the evolution of smaller direct-to-consumer (DTC) brands on the purchasing capacity of consumers, to analyse challenges in branding in Tier 2 and 3 cities and to evaluate the strategic branding decisions of Mamaearth. Case overview/synopsis: During her pregnancy, Ghazal Alagh and her husband Varun Alagh, the co-founders of Mamaearth, were looking for some good and natural products for their babys skincare. However, she could not find products that were 100% safe. Hence, as a concerned mother, she started using a few hands-on home remedies for her baby, which were 100% organic, and then the idea clicked to her to start a baby care brand named Mamaearth, which later also included personal care products. The company started as a DTC/internet-first brand in 2016, which only used to sell products online without any intermediaries when it was still trying to make its way in the market and was aware of the stiff competition by giants such as Hindustan Unilever and Proctor & Gamble, who were ruling the market for decades. When the COVID-19 pandemic hit, the market saw a shift in consumer buying patterns. There was greater use of e-commerce touch points for shopping, as various digital platforms such as the official site of products, social media and mobile platforms were used by consumers during the pandemic, leading to digitalization in buying and digitalization of consumer shopping journey. These technology platforms were expected to play a substantial role in reaching and creating consumer awareness, transaction and retention post-COVID according to reports by Deloitte 2020. Moreover, such a shift in behaviour amidst the COVID-19 pandemic shot up sales of this DTC brand and made itself the big shot it is today, where they were looking to get into an initial public offering in just seven years of its launch. They re-evaluated their strategy, which helped them become the biggest brand in no time. Complexity academic level: This case study is suitable for Doctor of Philosophy students. Supplementary material: Teaching notes are available for educators only. Subject code: CSS 8: Marketing. 2023, Emerald Publishing Limited. -
Marketing odyssey for a digitally native brand: a case study of Sunbird Straws
Research methodology: The case study incorporated a combination of primary and secondary data collection approach. The authors interviewed Dr Varghese, the co-founder of Sunbird Straws and the protagonist in this case study. In addition, secondary data was obtained from various sources such as newspaper articles, journal publications and company reports. Case overview/synopsis: On a rosy and vibrant morning in 2017, Dr Saji Varghese, a professor at Christ University in Bangalore, stumbled upon a curved coconut leaf on the campus resembling a straw. This sparked his motivation to transform coconut leaves into a natural straw, prompting him to initiate experiments with coconut leaves in his kitchen. The process of boiling and straining leaves became his method for crafting an eco-friendly straw. After numerous attempts, he successfully produced straws from coconut leaves, introducing a distinctive and creative concept incubated at IIM Bangalore. These unique straws, crafted by Varghese, prioritised environmental friendliness and were also crafted entirely from biodegradable materials, free from harmful chemicals. These straws demonstrated durability in hot and cold beverages for up to 3 h, maintaining their integrity without becoming soggy or leaking. As the business flourished, it reached a critical juncture. The primary challenge centred around product marketing, mainly due to consumer unfamiliarity with such sustainable straws. This was a product that also fell under the category of low involvement for consumers. Raising awareness about the product and persuading consumers to purchase presented a significant hurdle. In response, Varghese assigned his team to develop cost-effective marketing strategies. Given the start-up nature of the business, advertising budgets were constrained, and the objective was to achieve a positive return on advertising spend for every investment in advertising the product. In addition, the focus was on increasing the likelihood of selling the straws on both business-to-business and business-to-consumer levels. In this case study, Vargheses role and predicament exemplify the delicate equilibrium that entrepreneurs frequently grapple with, striking a balance between marketing strategy and return on ad spent to steer the trajectory of their businesses. It offered a valuable examination of the nuanced decisions marketers encounter as they strive for both profitability and customer-centric products. Complexity academic level: The case study is relevant to the marketing discipline. All undergraduate and postgraduate-level marketing courses in higher education institutions can use this case study. It can also be used in integrated marketing communication or digital marketing classes. It can be used further in the hospitality and management fields. Also, online courses in marketing can include this case study. 2024, Emerald Publishing Limited. -
Navigating brand equity in personal care: Examining the influence of direct-to-consumer brands and the mediating power of brand image
The COVID-19 pandemic triggered consumers to buy products online, leading t o unprecedented and unforeseen growth in the e-commerce sector. Therefore, the revolution made by Direct-to-consumer (DTC) brands went unnoticed. Unlike the conventional approach, which took years to build brand trust and equity, the DTC business model allows companies to grow exponentially with their presence in personal care online marketplaces. Therefore, the rise of DTC brands empowers small and medium enterprises (SMEs) and micro small and medium enterprises (MSMEs) in India, mainly because the return on ad spend (ROAS) for these brands is a huge problem when compared to giant companies. Also, branding in tier 2 and tier 3 markets has triggered new hurdles as consumers need to build brand trust to pay or transact online. The present research examines how a DTC website and electronic word-of-mouth (eWOM) can enhance the effectiveness of branding for direct-to-consumer brands. The study employed a quantitative methodology by analyzing the survey-based research design, with 389 respondents who were aware of and/or used DTC personal care brands in India participating. The present studys findings demonstrate that website attractiveness and electronic word-of-mouth enhance DTC brands and minimize costs developed to advertise a product, increasing ROAS. Further research studies would broaden DTC brands' knowledge by investigating the impact of e-commerce and social media channels on enhancing consumers' brand equity or purchase intention. 2024 Conscientia Beam. All Rights Reserved. -
Star-forming, rotating spheroidal galaxies in the GAMA and SAMI surveys
The Galaxy And Mass Assembly (GAMA) survey has morphologically identified a class of 'Little Blue Spheroid' (LBS) galaxies whose relationship to other classes of galaxies we now examine in detail. Considering a sample of 868 LBSs, we find that such galaxies display similar but not identical colours, specific star formation rates, stellar population ages, massto- light ratios, and metallicities to Sd-Irr galaxies. We also find that LBSs typically occupy environments of even lower density than those of Sd-Irr galaxies, where ?65 per cent of LBS galaxies live in isolation. Using deep, high-resolution imaging from VST KiDS and the new Bayesian, 2D galaxy profile modelling code PROFIT, we further examine the detailed structure of LBSs and find that their Ssic indices, sizes, and axial ratios are compatible with those of low-mass elliptical galaxies. We then examine SAMI Galaxy survey integral field emission line kinematics for a subset of 62 LBSs and find that the majority (42) of these galaxies display ordered rotation with the remainder displaying disturbed/non-ordered dynamics. Finally, we consider potential evolutionary scenarios for a population with this unusual combination of properties, concluding that LBSs are likely formed by a mixture of merger and accretion processes still recently active in low-redshift dwarf populations.We also infer that if LBS-like galaxies were subjected to quenching in a rich environment, they would plausibly resemble cluster dwarf ellipticals. 2019 The Author(s). -
Smart Edge Computing for 5g/6g Satellite IOT for Reducing Inter Transmission Delay
5G/6G communication are first generation high speed wireless communication network which integrates the aerial data, terrestrial data and maritime data via satellite to IoT cellular devices. Technological motivation tends to increase the satellites day by day for supporting most of global applications. These applications highly relay on satellite data for processing users request and giving appropriate outcome to the users. World grows very fastly with new technologies which makes demand for fastest data communication. Handling the satellite IoT data is worthiest research problem and it must be paid with more attention. At present inter satellite communication face high delay with lower data utilization rate. The effective utilization of data generated by satellite IoT is processed using our proposed intelligent model called smart edge computing (SEC-5G) for 5G. The SEC-5G embeds with satellite for reducing the data transfer limitation and delay in inter satellite communication. In this research we highly concentrate on satellite IoT data and its problem. Our proposed system reduces the limitation in inter satellite data communication rate which makes higher delay in data processing and utilization. In this article, smart edge computing is designed for satellite IoT using SDN/NFV and deep convolutional neural network (DCNN) with logical ring construction. The task uses SDN/NFV model to choose edge node, cloud node in the smart edge computing. Based on training data, DCNN works on SEC-5G software model. Smart architecture helps to increase the performance, scalability, reliability of satellite edge computing model. This architecture works with machine learning model and helps to improve the future satellite speed on data processing. The performance of the proposed is compared with existing Ground 5G. Evaluated outcome shows proposed embedded satellite outperforms in data communication. 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature. -
Effectiveness of public policy in reviving the COVID-19 hit economy: Evidences from Kerala, India
The economic crisis triggered by the COVID-19 urgently required active policy interventions to enhance the revival strategies of the world economy. This paper examines the effectiveness of policy intervention of the State Government of Kerala in India in mitigating the risks caused by the pandemic. The policy effectiveness is evaluated by analyzing the data collected from a sample of 300 beneficiaries with the help of descriptive statistics, ordered probit (OP) model, and semi nonparametric extended OP (SNEOP) model. Our results are assertive with the fact that state policies are effective in reviving the crisis-hit economy as they have primarily helped low-income groups and other marginalized communities. The majority of BPL families, self-help group members, and social security beneficiaries rated government policies as highly or fairly effective. Though the policies are found to be highly effective among those who have suffered income loss, the study does not find sufficient evidence to believe that the government interventions are effective in helping those who have lost their jobs. The level of effectiveness is inversely related to age, education, and family size. Our results suggest that an extensive fiscal package is required to help people recover from the crisis. 2021 John Wiley & Sons Ltd. -
A new lightweight data security system for data security in the cloud computing
In recent decades, data has proved indispensable to all facets of human existence. The development of several applications has resulted in the exponential expansion of data. This information can be encrypted and stored in secure areas. Cloud computing is the technology that can be used to store these massive data sets. The article suggests a Cloud-based Data Security System (C-DSS) that employs a five-tiered trust model for cloud-edge data-sharing architectures. The data owner can select an appropriate trust level and Cyber Threat Information (CTI) sanitization procedure before releasing CTI for analytic strategy. In addition, this cleansing method is conducted either by an end device or by the cloud service supplier, based on the organization's degree of confidence in latter. Research presents the trust architecture, cloud architecture, and installation methodology, all of which are intended to meet widest variety of needs for exchanging secret CTI information. The testing findings high degree of data security and an evident improvement in terms of cypher processing time and security services when compared to the encryption systems that are most often employed in cloud technology. In conclusion, research briefly outlines development and evaluation performed so far by pilot applications confirming the architecture. 2023 The Authors -
Well-being and Career Decision-making Difficulties Among Masters Students: A Simultaneous Multi-Equation Modeling
There is a stellar upsurge in the number of persons pursuing a masters level of education as well as the institutions offering it in the current generation. Nevertheless, an explicit theoretical and empirical implication of how the tutelages, at this level, shape the well-being of learnerssuch that it could help individuals overcome career decision-making difficulties remains to be elucidated. The present study addressed two major objectives. Firstly, we investigated the well-being of masters degree students along with career decision-making difficulties in India. Secondly, apart from exploring the possible influence of nationality of the respondents on career decision difficulty, the study expanded the literature on career decision-making difficulties to under-researched populations in developing countries. Through a cross-sectional research design, we recruited a sample of 136 masters degree respondents. The result reveals that while the composite well-being resources significantly influenced Career Decision Difficulties, the nationality of respondents appeared not as a germane factor in this context. Following the evaluation of the direct effect of individual well-being resources; Self-acceptance and Personal growth proved to have a statistically significant effect on career decision-making difficulties. Also, among the constituents of career decision-making difficulties studied, lack of readiness appears to be the major concern among the respondents. The findings expand the literature on cognitive, vocational, and organization science vis-a-vis career decision-making difficulties and provide useful insights for educational institutions and practitioners. 2021 The Author(s). This open access article is distributed under a Creative Commons Attribution (CC-BY) 4.0 license. -
Job satisfaction while working from home during the COVID-19 pandemic: do subjective work autonomy, work-family conflict, and anxiety related to the pandemic matter?
The imposed lockdown, due to the COVID-19 outbreak, resulted in the rise to a new normal of working from home. This study explores how the lockdown and the sudden shift in the working style affected the job satisfaction of employees in India. We examined the relationship of job satisfaction with work autonomy, and determined whether work-family conflict, and anxiety due to COVID-19 are negatively related to job satisfaction amongst employees working from home in India. Through a correlational research design, a total of 211 participants took part in the study, and only 200 of the data, representing a 95% response rate, were eligible for further analysis. The data were analyzed using Structural Equation Modeling, and the results showed that work-family conflict and anxiety related to COVID-19 have a negative correlation with job satisfaction, while work autonomy had a positive correlation with job satisfaction. Perceived work autonomy, work-family conflict, and anxiety related to the COVID-19 pandemic significantly predicted job satisfaction and accounted for an overall 37.8% of the variance in job satisfaction. The findings of the current study provide valuable insight into the consequences of a pandemic or similar uncontrollable event, and augmented the literature on organizational behavior where most employees are compelled to work remotely, either full-time or part-time. The theoretical and empirical implications of how work-family conflict and anxiety related to the COVID-19 pandemic negatively impact the job satisfaction of employees in India were discussed. Evaluation of the structural relationship (SEM) reveals that the overall exogenous constructs significantly predicted job satisfaction of employees working from home in India during the COVID-19 pandemic. 2022 The Author(s). This open access article is distributed under a Creative Commons Attribution (CC-BY) 4.0 license. -
Effect of background music and the cultural preference to music on adolescents task performance
There is a plethora of research assessesing the effect of background music on task performance; however, these results have largely been inconclusive and divided. Music is a powerful medium that possesses a lot of positive benefits. This paper addresses the gaps in the existing literature and attempts to explore the effect of background music on adolescents performance in a reading comprehension task. It also examines the role of culture in the said effect of performance, by assessing whether ones own culture leads to a better performance when compared to both silence and music from a different culture. To this end, an experimental study was conducted on 34 adolescents between the ages of 1314 (M = 13.50, SD = 0.50). The results indicate that a strong positive effect is achieved on task performance when background music is present, especially one that identifies with the participants cultural background. 2020, 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. -
Surface modified graphene/SnO2 nanocomposite from carbon black as an efficient disinfectant against Pseudomonas aeruginosa
Carbon based nanocomposite with well-defined integrated properties are highly sort after in the field of nanobiotechnology and nanomedicine. We report a facile one step hydrothermal route for the production of graphene sheets interlaced with SnO2 nanoparticles. Graphene oxide (GO)sheets are obtained by the surface functionalization of powdered carbon black. A facile hydrothermal method is employed to integrate SnO2 nanostructures over the graphene surface. All the samples exhibited long term stability and unique fluorescence response with no sign of photobleaching even after a storage of 30 months. Antibacterial activity of the samples at each stage is tested against Pseudomonas aeruginosa, which is a highly resilient bacterial strain possessing very high attributable mortality rate and causes a variety of ailments from diarrhea to meningitis. Bactericidal activity of carbon black, GO derived from carbon black and graphene-SnO2 nanocomposite is tested against Pseudomonas aeruginosa using disk diffusion assay for the first time. Comparing the zone of inhibition produced by carbon black, GO and the nanocomposite, highest antibacterial performance is exhibited by the nanocomposite sample (25 0.3 mm)followed by GO (16 0.5 mm)and pristine carbon black (14 0.3 mm). The bactericidal ability of the nanocomposite increased by ?79% compared to pristine carbon black. MIC analysis revealed that the nanocomposite could inhibit the bacterial growth at a much lower concentration (250 ?g/mL)compared to the precursors. The high antibacterial efficacy and long-term stability of graphene-tin oxide nanocomposite synthesized from carbon black facilitates its usage as a potent antibacterial agent in disinfectant and sanitation industry. 2019 Elsevier B.V. -
Facile synthesis of graphene-tin oxide nanocomposite derived from agricultural waste for enhanced antibacterial activity against Pseudomonas aeruginosa
Antibacterial screening of graphene-tin oxide nanocomposites synthesized from carbonized wood and coconut shell is investigated against Pseudomonas aeruginosa for the first time. Efficient and facile one step hydrothermal process adopted in the present work for the synthesis of graphene-tin oxide nanoparticles provides an ideal method for the economic large-scale production of the same. Graphene-tin oxide nanocomposites derived from wood charcoal possess a spherical morphology whereas rod like structures are seen in the case of coconut shell derivatives. An excitation independent fluorescence response is observed in graphene-tin oxide nanohybrids while graphene oxide nanostructures exhibited an excitation dependent behavior. These hydrophilic nanostructures are highly stable and exhibited no sign of luminescence quenching or particle aggregation even after a storage of 30 months. Bactericidal effects of the nanostructures obtained from coconut shell is found to be relatively higher compared to those procured from wood. This variation in antibacterial performance of the samples is directly related to their morphological difference which in turn is heavily influenced by the precursor material used. MIC assay revealed that coconut shell derived graphene-tin oxide composite is able to inhibit the bacterial growth at a lower concentration (250 ?g/mL) than the other nanostructures. Nanocomposites synthesized from agro-waste displayed significantly higher antimicrobial activity compared to the precursor and graphene oxide nanostructures thereby making them excellent candidates for various bactericidal applications such as disinfectants, sanitary agents etc. 2019, The Author(s). -
Extraction of Graphene Nanostructures from Colocasia esculenta and Nelumbo nucifera Leaves and Surface Functionalization with Tin Oxide: Evaluation of Their Antibacterial Properties
Expeditious evolution of antimicrobial resistance in recent years has been identified as a growing concern by various health organizations around the world. Herein, facile and environmentally benign production of highly antibacterial carbonaceous nanomaterials from Colocasia esculenta and Nelumbo nucifera leaves is reported. After carbonization and oxidative treatment, smaller graphene domains are formed in Colocasia esculenta derivatives, whereas larger sheetlike structures are observed in the case of Nelumbo nucifera. Smaller particle size makes quantum confinement effects more prominent, as is evident in fine-tuning of the photoluminescence emission after each stage of treatment. The influence of precursor materials on the antibacterial properties of the nanosystems is also demonstrated. When microbiocidal activity was tested against model bacteria Pseudomonas aeruginosa, the nanocomposite derived from Colocasia esculenta leaves showed higher activity than the antibiotic drug clarithromycin (control) with a measured zone of inhibition of 400.5 mm. This is one of the highest values reported in comparison with plant-based carbonsilver nanosystems. Quantitative analysis revealed that the nanocomposite obtained from Colocasia esculenta leaves has antimicrobial efficacy equivalent to those of commercial antibiotic drugs and is able to eradicate bacteria at much lower concentrations than that obtained from Nelumbo nucifera leaves. 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim -
Biowaste derived graphene quantum dots interlaced with SnO2 nanoparticles-a dynamic disinfection agent against: Pseudomonas aeruginosa
Highly resilient antibacterial strains are a major cause of concern in the modern sewage treatment and sanitation industry. Hence, development of efficient, low-cost disinfectant agents is essential. In this study, synthesis of graphene quantum dots (GQDs) from expended sugarcane bagasse via surface functionalization and the subsequent production of GQD/SnO2 nanocomposites via a facile hydrothermal route is demonstrated for the first time. The synthesized nanostructures are found to be studded with various oxygen moieties and exhibit an excitation independent fluorescence behaviour implying the existence of quantum confinement effects. Nanoparticles obtained after the hydrothermal treatment are found to possess spherical morphology with an average particle size of 4.5 nm. Antibacterial activity of the synthesized product is tested against Pseudomonas aeruginosa using the disc diffusion assay and minimum inhibitory concentration assay. A marked rise in the antibacterial performance is seen in the nanocomposite compared to its carbonized and GQD counterparts. This can be attributed to the presence of surface defects and smaller uniform sized particles. These cost-effective nanostructures are photo stable for extended periods of storage and may find excellent utility in the sanitation and disinfectant industry. 2019 The Royal Society of Chemistry and the Centre National De la Recherche Scientifique. -
Synthesis and characterization of carbon nanospheres from hydrocarbon soot
Foreseeing the upcoming era of the carbon nanomaterials and their revolutionary applications, we have identified and explored the structural parameters of five effective precursors of the same-carbon black, soot obtained by the thermal decomposition of kerosene, diesel, paraffin wax and lubricant oil. Micro-Raman spectroscopy, Fourier Transform Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), Scanning Electron Microscopy, Electron dispersive spectroscopy (EDS) and elemental analysis are employed for the structural and morphological characterization of the nanomaterials formed. The average lateral size (La), stacking height (Lc) and interlayer spacing (d002) of the crystallite structures calculated from the X-ray intensities are found to be ranging from 4.3-5.9 nm, 0.63-2.40 nm and 3.10- 3.68 respectively. La values determined by Raman and XRD analysis are in very good agreement thereby reinforcing the nanocrystalline structure of the samples. The very low I20/I26 ratio obtained reveals a relatively low amount of disorder in the nanostructures. Nanomaterials formed have the morphology of non-uniform nanospheres with diameter varying between 26-100 nm. EDS and elemental analysis confirms the absence of metal impurities. FTIR spectra of the samples shows the presence of stretching vibrations of -OH bonds, aliphatic -CH, -CH2 and -CH3 absorptions, C=C and -CH absorptions of aromatic structures. 2012 by ESG. -
Probing the nature of defects of graphene like nano-carbon from amorphous materials by raman spectroscopy
Raman spectral characterization of selected carbonaceous materials has been carried out at excitation wavelengths 514, 633 and 1064 nm. Raman studies exhibit the presence of G band owing to the first order of E2g mode scattering. sp3 domains at about 1355 cm-1 (D band) are ascribed to the disordered structures due to the on-site and hoping defects which introduces distortions in the crystal lattice. Spectral de-convolution indicates the prominence of bands namely G, D1, D2, D3 and D4. D3 and D4 bands follow Gaussian, while the others Lorentian distribution. With change in excitation wavelength of laser, the degree of dispersion of G peak and ID/IG intensity ratio are found to increase. The crystallite size La, shows an inverse relation with intensity of defect to graphite band (ID/IG) and it also obeys Tuinstra-Koenig relation for nano-crystalline substance. The lateral size of aromatic lamellae determined using XRD analysis is in good agreement with that of Raman analysis. The feasibility of using kerosene soot, diesel soot and carbon black for electrochemical applications are also explored.