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Effect of alkyl chain length on the corrosion inhibition of mild steel in a simulated hydrochloric acid medium by a phosphonium based inhibitor
The corrosion inhibiting effect of three synthesised phosphonium containing ionic liquids of varying alkyl chain length, namely, butyltriphenyl phosphonium bromide (BTPPB), hexyltriphenyl phosphonium bromide (HTPPB) and hexadecyltriphenyl phosphonium bromide (HDTPPB) on mild steel, was evaluated in 1 M HCl medium. The corrosion inhibition performance was studied by gravimetric method, potentiodynamic polarization studies, electrochemical impedance spectroscopy and quantum chemical studies (DFT). However, the results of the SEM, AFM and contact angle tests confirmed that the protective layer formed on the mild steel. Furthermore, assessed the theoretical calculations for exploring the inhibition mechanism. A maximum of 95.77% inhibition efficiency was achieved using 250 ppm of HDTPPB. The obtained results showed that HDTPPB has greater inhibition ability than BTPPB and HTPPB. Adsorption studies obeyed the Langmuir adsorption isotherm. Moreover, the increased alkyl chain length of ionic liquids did increase their inhibition efficiency. 2021 Informa UK Limited, trading as Taylor & Francis Group. -
Effects of supply chain integration on firms performance: a study on micro, small and medium enterprises in India
The cooperation in the supply chain assumes an adequate job for enhancing an organisation's performance and increasing competitive advantage. Supply Chain Integration (SCI) affects organisational performance. This paper studies the impact of the integration of supply chain procedures and practices on organisational performance and explores the effect of SCI on organisational performance at Micro, Small and Medium Enterprises (MSMEs) in Madurai District, Tamilnadu, India. A questionnaire is developed with validated measurement scales from previous studies and empirical data are collected through a survey questionnaire from 250 randomly selected MSMEs. This research provides sound recommendations to MSMEs in Madurai District, Tamilnadu, India, and maybe used for different industries and decision making policies. Finally, the study will contribute to the scientific field by providing some future studies. 2020 by the authors; licensee Growing Science, Canada. -
Causality and volatility spillovers of banks' stock price returns on BSE Bankex returns
This paper investigates the causal relationships and volatility spillovers between the BSE Bankex index and the stock prices of five major Indian banks (Axis Bank, HDFC Bank, ICICI Bank, Kotak Bank, and SBI). Daily data from January 2, 2018 to March 8, 2023 are used, and statistical techniques such as descriptive statistics, Unit Root test, Cointegration test, Ganger Causality test, OLS regression, and GARCH model are employed. The study finds bidirectional causal relationships between the bank stocks and BSE Bankex returns, suggesting that the movement of the bank stocks significantly affects the overall market returns and vice versa. The study also finds significant volatility spillovers between the bank stocks and BSE Bankex returns, implying that the shocks in the bank stocks affect the market returns and vice versa. The study's outcomes have practical implications for investors and policymakers. Investors can use the results to make informed investment decisions in the Indian stock market, while policymakers can use the findings to monitor the financial stability of the banking sector and design appropriate policy interventions to address any potential financial crises. Overall, the study's findings suggest that policymakers should proactively monitor and manage market risks to safeguard overall financial stability. 2023 Wiley Periodicals LLC. -
Stress mindset as a mediator between self-efficacy and coping styles
Stress mindset is a lens through which one views stress and its consequences as beneficial or harmful for them. It is a distinct variable that differs from frequency, amount, and intensity of stress. The literature review indicated that stress mindset could mediate the link between self-efficacy and coping style, which was previously not tested. Hence, the study aimed; 1) to examine the relationship between self-efficacy, stress mindset, and coping style; 2) to investigate the influence of stress mindset and self-efficacy on coping styles; 3) to find whether stress mindset mediates the association between self-efficacy and coping styles. The study employed a correlational research design, whereby through multi-phase sampling recruited 727 participants (male = 300, female = 427, mean age = 16.26) studying in 11th and 12th standard. The researchers administered validated stress mindset, self-efficacy, and coping style and performed a multiple correlational and regression analysis. They computed mediation analysis using Hayes model 4 in Process Macro. The finding indicated that the association between self-efficacy and self-controlling coping style is mediated by stress mindset. Furthermore, it mediated the connection between some sub-domains of self-efficacy and coping styles. The data were evident to infer that individual with high self-efficacy can interpret social stressors as beneficial and improve their coping skills. 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. -
Diversifying investor's portfolio using bitcoin: An econometric analysis
Rational investors look into maximizing returns with minimal risk. Since this is highly unlikely, optimizing risk and return is a practical solution. Bitcoin is a new financial product that can be included in an investment portfolio. This paper looks at Bitcoins as a separate asset class and attempts to capture the volatility using the Exponential GARCH (E-GARCH) as well as to check if Bitcoins can be used as an optimal tool to hedge using the Dynamic Conditional Correlation GARCH against four traditional asset classes in the U.S. economy which includes the stock market (S&P 500 index), Bonds (U.S. Aggregate Bond Index), Gold and Crude Oil. The period of study is a little over 7 years. The results suggest that Bitcoin stands as a highly speculative class of asset with extremely high volatility and with respect to hedging, Bitcoin stands as a possible tool of hedge with the U.S. Aggregate Bond index and to a certain extent against Gold but fails to be an optimal hedge against the S&P 500 and Crude Oil in the U.S. economy between April 29, 2013 and October 31, 2019 due to its highly volatile nature. 2020 John Wiley & Sons, Ltd. -
KMSBOT: enhancing educational institutions with an AI-powered semantic search engine and graph database
In the rapidly evolving field of education, a semantic search engine is essential to efficiently retrieve knowledge experts data. Universities and colleges continuously generate a vast amount of educational and research data. A semantic search engine can assist students and staff in efficiently searching for required information in such a big data pool. The existing systems have limitations in providing personalized recommendations that align with the individual learning objectives of students and scholars, thus hindering their educational experience. To address this, this paper proposed a KMSBOT. This novel recommendation system effectively summarizes academic data and provides tailored information for students, research scholars, and faculty, enhancing educational experiences. This paper meticulously details the development of KMSBOT, which comprises a neo4j-based knowledge graph technique, the NLP method for data structuring, and the KNN machine learning model for classification. The system employs a three-module approach, utilizing data structuring, NLP processing, and semantic search engine integration. By leveraging Neo4j, NLTK, and BERT in Python, this proposed work ensures optimal performance metrics such as time, accuracy, and loss value. The proposed solution addresses traditional recommendation systems limitations and contributes to a brighter future, improving user satisfaction and engagement in academic environments. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024. -
Channel Selection Using Stochastic Diffusion Search Algorithm for Classification in Brain-Computer Interface
Utilization of the Brain-Computer Interfaces (BCI) is done via Electroencephalogram (EEG) signals that provide several environmental interactions among individuals having restricted movements owing to neurodegenerative diseases or strokes. However, the BCI system was based on Motor Imagery (MI). It was not used for any form of real-life application owing to a decrease in the performance of various Common Spatial Pattern (CSP) algorithms, especially while the actual number of channels was high. A multi-channel structure of such EEG signals can increase cost and bring down speed. Due to this, a reduction in the system cost by the detection of active electrodes during the process can increase accessibility. This way, optimization techniques in choosing electrodes can be used to determine other effective channels by employing a method of random selection. For this work, a Stochastic Diffusion Search (SDS) algorithm based on herd optimization techniques was used with four different classifiers, which were the AdaBoost, the Classification and Regression Tree (CART), the Naive Bayes (NB) as well as the K-Nearest Neighbor (KNN). The channels that were chosen frequently were determined to improve the system performance with regard to accuracy and speed. The results proved that the approach proposed was successful in bringing down the channel number and run time without affecting the accuracy of classification. 2024 Seventh Sense Research Group. -
Designing a One-Pot Ternary Fe-Mn-Zn Oxide Positive Electrode with Enhanced Energy-Storage Properties for Hybrid Supercapacitors
In recent years, ternary metal-oxide nanocomposite-based active electrodes have been investigated more effectively for supercapacitor applications due to the existence of a greater number of electroactive sites and the synergistic effect of three different transition-metal ions. Herein, Fe-Mn-Zn oxide ternary nanocomposites are synthesized using a simple and cost-effective one-pot hydrothermal approach. The characterizations of XRD, FTIR, FESEM, EDX, HRTEM, and XPS are analyzed for the synthesized Fe-Mn-Zn oxide nanocomposites to study their phases, functional groups, morphologies, purity, and binding energies. The electrochemical characteristics for the developed electrodes are studied in a three-electrode technique using CV, GCD, EIS, and a cyclic stability test. As expected, the ternary nanocomposite electrode of Fe-Mn-Zn oxide reveals a maximum specific capacitance (Cspc1) of 1673.4 F/g in comparison to other developed electrodes of ZnFe2O4 (271.7 F/g) and ZnMn2O4 (412.7 F/g) at the appropriate scan rate of 10 mV/s. In addition, the Fe-Mn-Zn oxide ternary nanocomposite active electrode exhibits 2616.25 F/g of total capacitance (qT**), 686.94 F/g of outer capacitance (qO**), and 1929.30 F/g of inner capacitance (qI**) which are determined by Trasatti analysis. Moreover, the fabricated hybrid supercapacitor device provides a good specific capacitance of 320.8 F/g, a high energy density of 75.3 Wh/kg at the power density of 649.9 W/kg at 1 A/g of current density range, and 88.75% of superior capacitive retention over 10,000 cycles at 10 A/g. Therefore, a ternary metal-oxide nanocomposite electrode is proposed to be a promising material for energy-storage devices. 2024 American Chemical Society. -
A new stepwise method for selection of input and output variables in data envelopment analysis
Data envelopment analysis (DEA) is one of the widely accepted optimization technique uses to measure the relative efficiency of organizational units where multiple inputs and outputs are present. The significance of DEA results depends on the variables selected for DEA modelling. One of the main challenges in data envelopment analysis modelling is of identify the significant input and output variables for DEA modelling. In this study, we propose an enhanced stepwise method to identify the significant and insignificant input and output variable by reducing the iterations process in stepwise method. The statistical significance of the input and output variables evaluated using the statistical methods: Least significance difference (LSD), and Welchs statistics. The proposed method applied to the Indian banking sector and the results have shown that the proposed model significantly identified the significant and insignificant input and output variables with least loss of information. 2021 the author(s). -
Some new results on equitable coloring parameters of graphs
An equitable coloring of a graph G is a proper vertex coloring C of G such that the cardinalities of any two color classes in G with respect to C differ by at most one. Coloring the vertices of a graph G subject to given conditions can be considered as a random experiment. In this context, a discrete random variable X can be defined as the color of a vertex chosen at random, with respect to the given type of coloring of G and a probability mass function for this random variable can be defined accordingly. In this paper, we discuss two statistical parameters of the powers of certain graph classes with respect to their equitable colorings. 2019, Univerzita Komenskeho. All rights reserved. -
The sparing number of certain graph powers
Let N0 be the set of all non-negative integers and P(N0) be its power set. Then, an integer additive set-indexer (IASI) of a given graph G is an injective function f : V(G) ! P(N0) such that the induced function f+ : E(G) ! P(N0) deffned by f+(uv) = f(u) + f(v) is also injective. An IASI f is said to be a weak IASI if jf+(uv)j = max(jf(u)j; jf(v)j) for all u; v 2 V(G). A graph which admits a weak IASI may be called a weak IASI graph. The set-indexing number of an element of a graph G, a vertex or an edge, is the cardinality of its set-labels. The sparing number of a graph G is the minimum number of edges with singleton set-labels, required for a graph G to admit a weak IASI. In this paper, we study the admissibility of weak IASI by certain graph powers and their corresponding sparing numbers. 2019 Sciendo. All rights reserved. -
The sparing number of the powers of certain Mycielski graphs
In this paper, we discuss the sparing number of the power graphs of the Mycielski graphs of certain graph classes. Journal Algebra and Discrete Mathematics. -
On the rainbow neighbourhood number of Mycielski type graphs
A rainbow neighbourhood of a graph G is the closed neighbourhood N[v] of a vertex v ? V (G) which contains at least one colored vertex of each color in the chromatic coloring C of G. Let G be a graph with a chromatic coloring C defined on it. The number of vertices in G yielding rainbow neighbourhoods is called the rainbow neighbourhood number of the graph G, denoted by rX(G). In this paper, we discuss the rainbow neighbourhood number of the Mycielski type graphs of graphs. 2018 Academic Publications. -
Green synthesis and electrochemical characterization of rGOCuO nanocomposites for supercapacitor applications
Reduced graphene oxide (rGO) were prepared from graphene oxide (GO) by using piperine as a green reducing agent extracted from Piper nigrum. The obtained rGO had few defects and lacked connectivity between the layers. To overcome these defects, copper oxide (CuO) nanoparticles were synthesized ultrasonically and nanocomposites of rGOCuO were prepared. The conductivities of the rGO, CuO and rGOCuO nanocomposites were determined by AC impedance spectroscopy in different electrolytes. Morphology, composition and electronic structure of CuO, rGO and rGOCuO nanocomposites were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photon spectroscopy (XPS) and electrochemical techniques. Transmission electron microscopy (TEM) images portrait CuO as a fish caught in the net of rGO layers. The rGOCuO nanocomposite exhibiting lower resistance and higher capacitance was used in fabrication of supercapacitor electrodes. The specific capacitance of the fabricated supercapacitor was found to be 137Fg?1. The supercapacitor performance of the nanocomposite electrode is attributed to the synergistic effect of double-layer capacitance of rGO and redox capacitance of CuO nanoparticles. [Figure not available: see fulltext.] 2016, Springer-Verlag Berlin Heidelberg. -
Investigations on thermo-mechanical properties of organically modified polymer clay nanocomposites for packaging application
Eco-friendly packing polymer materials are in the spotlight but, lack of new biodegradable polymers either natural or synthetic is yet to establish the market more competitively. So, in the present work, clay as a nano-filler is embedded and organically modified in some synthetic and natural polymers which are well established commercially to enhance their biodegradability. The impact of clay on the properties of synthetic polymers namely, poly(methyl methacrylate) (PMMA), poly(vinyl chloride) (PVC), poly(vinyl acetate) (PVAc) and natural polymer cellulose acetate butyrate (CAB) was studied. Results from differential scanning calorimetric (DSC) showed a decrease in the glass transition temperature of organically modified polymer clay nanocomposites (PCC) than pure polymers. Scanning electron microscopy (SEM) displayed a uniform surface with small-sized crystallites distributed on the polymer surface. X-ray diffraction (XRD) spectra revealed the formation of enhanced intercalated structures in PCC. Furthermore, FTIR studies showed that the interlayer bonding (SiO bands) of pure clay is deformed in PCCs. The tensile strength of PCC increased with an increase in organo-clay loading. This unique mechanical behavior is due to the agglomeration of organo-clay particles. Finally, the biodegradation studies revealed enhanced hydrolytic degradation in PCC than pure polymers. Hence, these PCCs are environmentally friendlier than their pure synthetic polymers without significant compromise in their properties, which makes it suitable for packaging industries. The Author(s) 2020. -
Supercapacitor studies of activated carbon functionalized with poly(ethylene dioxythiophene): Effects of surfactants, electrolyte concentration on electrochemical properties
Electropolymerization of poly(ethylene dioxythiophene) (PEDOT) on activated carbon (AC) was performed using different surfactants such as anionic surfactant (sodium dodecyl sulfate), protonic surfactant (camphor sulphonic acid) and non-ionic surfactant (Triton) in 0.1 M H2SO4. The effects of concentration of different surfactants for electrodeposition of PEDOT on AC were analyzed using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and SEM techniques. Supercapacitors (SC) were fabricated using AC/PEDOT composite electrodes and 0.1 M H2SO4 as an electrolyte. The specific capacitance (Cs) values were calculated using CV at different concentrations of surfactants, electrolytes and variation of potential. The electrolyte containing 0.1 M H2SO4 and 0.02 M camphor sulphonic acid showed to have the highest specific capacitance value of 240 Fg?1 than other surfactant based SCs. Galvanostatic charge/discharge at varying current density were performed on SCs containing different surfactant based electrodes to study their cyclic stability. 2020 -
Green synthesis and electrochemical characterization of rGO–CuO nanocomposites for supercapacitor applications /
Lonics, Vol.23, Issue 5, pp.1267–1276, ISSN: 9477047. -
Revisiting television in India: Mapping the portrayal of women in soap operas /
Sociological Bulletin, Vol.67, Issue 2, pp. 204-219. -
Design of Reconfigurable FRM Channelizer using Resource Shared Non-maximally Decimated Masking Filters
This paper presents a reconfigurable frequency response masking (FRM) wideband channelizer architecture which is characterized by low computational and hardware complexity. The proposed hardware efficient architecture is realized by incorporating resource shared non-maximally decimated filter bank in the implementation of the FRM wideband channelizer structure. The coefficients of the proposed architecture are optimized and made multiplier-free using Pareto based meta-heuristic algorithm in the canonic signed digit (CSD) space for reducing the total power consumption of the architecture. The architecture is finally designed and synthesized using Xilinx Vivado and Cadence RTL Encounter compiler for the area and power analysis and is compared with existing channnelizer architectures. The comparison highlights the advantages of the proposed architecture in terms of hardware complexity, power and workload in realizing sharp wideband channel filters. 2020, Springer Science+Business Media, LLC, part of Springer Nature. -
Biotic elicitors influence boeravinone B production from cell suspension cultures of Boerhavia diffusa Linn.
Boerhavia diffusa L., (punarnava) is known for its rich, secondary metabolite content and potential pharmacological properties. Boeravinone B, a flavonoid, is a significant plant secondary metabolite found in punarnava, exhibiting various pharmacological properties that translate into anticancer, antioxidant, anti-inflammatory, immunomodulatory and nephroprotective activities. However, the limited production of boeravinone B within the plant poses challenges in meeting market demands. In this study, various biotic components, including filtrates and supernatants of algae, fungi, and bacteria, are employed as elicitors to enhance the production of boeravinone B from the cell suspension cultures of punarnava. Fungal components like yeast extract, Aspergillus niger and Cordyceps militaris, bacteria like Escherichia coli and Bacillus subtilis, as well as Algae such as Valonia utricularis and Spirulina platensis, are utilised to assess their efficiency as elicitors at different day intervals. Results indicate that among all the elicitor treatments, fungal components like yeast extract, C. militaris and A. niger at 100 mg/L, 1 % and 5 % concentrations, administered 6, 6 and 2, days before harvesting, exhibit increased production of boeravinone B by 1.13, 1.14 and 2.63 folds, respectively, when compared to control cultures. Similarly, algae V. utricularis and S. platensis, at 2.5 % concentration and treated before harvesting on Day 6, demonstrate enhanced production of boeravinone B by 1.74 and 4.40 folds compared to control cultures. In addition, the efficiency of various biotic elicitors is examined by quantifying total phenolics and flavonoids in treated cell suspension cultures. These findings have the potential to enhance production strategies and meet the growing demand for this valuable compound with medicinal properties, leveraging easily accessible biotic elicitors. 2024 SAAB