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On certain chromatic topological indices of some Mycielski graphs
As a coloring analogue of different Zagreb indices, in the recent literature, the notion of chromatic Zagreb indices has been introduced and studied for some basic graph classes in trees. In this paper, we study the chromatic Zagreb indices and chromatic irregularity indices of some special classes of graphs called Mycielski graphs of paths and cycles. 2020 Yarmouk University. All rights reserved. -
Chloroform fraction of Chaetomorpha brachygona, a marine green alga from Indian Sundarbans inducing autophagy in cervical cancer cells in vitro
Sundarbans Mangrove Ecosystem (SME) is a rich repository of bioactive natural compounds, with immense nutraceutical and therapeutic potential. Till date, the algal population of SME was not explored fully for their anticancer activities. Our aim is to explore the potential of these algal phytochemicals against the proliferation of cervical cancer cells (in vitro) and identify the mode of cell death induced in them. In the present work, the chloroform fraction of marine green alga, Chaetomorpha brachygona was used on SiHa cell line. The algal phytochemicals were identified by GCMS, LCMS and column chromatography and some of the identified compounds, known for significant anticancer activities, have shown strong Bcl-2 binding capacity, as analyzed through molecular docking study. The extract showed cytostatic and cytotoxic activity on SiHa cells. Absence of fragmented DNA, and presence of increased number of acidic vacuoles in the treated cells indicate nonapoptotic cell death. The mode of cell death was likely to be autophagic, as indicated by the enhanced expression of Beclin 1 and LC3BII (considered as autophagic markers) observed by Western blotting. The study indicates that, C. brachygona can successfully inhibit the proliferation of cervical cancer cells in vitro. 2020, The Author(s). -
Blockchain enabled energy efficient red deer algorithm based clustering protocol for pervasive wireless sensor networks
Energy efficiency and security are considered as important issues in the design of pervasive wireless networks. Since the nodes in pervasive wireless networks are battery-operated, it becomes essential to develop an energy-efficient method to minimize energy consumption and prolong the network lifetime. This paper presents new energy-efficient and secure clustering based data transmission in pervasive wireless networks using red deer algorithm (RDA) based clustering technique with blockchain enabled secured data transmission, named as RDAC-BC. The proposed RDAC-BC technique undergoes node initialization and performs the clustering process using the RDAC technique. The clustering technique performs cluster head (CH) selection and cluster construction process is carried out. Once the CHs are chosen, blockchain enabled secure data transmission takes place among cluster members (CMs) as well as CHs. The application of RDAC and blockchain technology helps to achieve energy efficiency and security. The experimental validation of the RDAC-BC technique is assessed under several aspects and the results are compared with existing methods. The obtained results ensured that the RDAC-BC technique has shown superior results interms of energy, network lifetime, packet delivery ratio (PDR), and throughput. 2020 Elsevier Inc. -
Rhetorics in/of English language education in India: A case of digital natives in higher education programs
The study briefly analyzes the ELT situation in India which is replete with challenges emerging from the lack of engagement with the phenomenon of digitality that further shapes the existing nature of learning and the needs of the learner. After locating the position of English Language in the new education policy of India, the paper discusses the General English (GE) courses offered at undergraduate level at the city of Bangalore in India, thereby shedding light on the existing gaps between policy and practice. It is based on this conjecture that the paper suggests the possibility of introducing rhetorical practices in GE courses at undergraduate levels in various institutions in urban India. In order to substantiate this suggestion, the results of a survey conducted with the learners (N=359) of a GE course based on rhetorics at a Southern Indian university is provided. Empirical data along with a brief reflection on the learners' voices are used in the study to examine the efficacy of the structure, administration and evaluation practices of this new course. The study thus opens up possibilities of initiating a discourse around the mode in which English language education and teaching is envisioned, formulated and implemented in undergraduate programs across urban India. 2020 ELE Publishing. All rights reserved. -
The effect of boundary conditions on the onset of chaos in RayleighBard convection using energy-conserving Lorenz models
The influence of 16 boundary conditions on linear and nonlinear stability analyses of RayleighBard system is reported. A StuartLandau amplitude equation for the RayleighBard system between stress-free, isothermal boundary conditions is derived and the procedure used in this derivation serves as guidance for constructing an appropriate FourierGalerkin expansion for the other 15 boundary conditions to derive a generalized Lorenz model. The influence of the boundary conditions comes within the coefficients of the generalized Lorenz model. It is shown that the obtained generalized Lorenz model is energy conserving and for certain boundary conditions it retains features of the classical Lorenz model. Further, the principle of exchange of stabilities is shown to be valid for the present problem and hence it is the steady-state, linearized version of the generalized Lorenz model which yields an analytical expression for the Rayleigh number. On minimizing this expression with respect to wave number the critical Rayleigh number at which the onset of regular convective motion occurs in the form of rolls is determined for all 16 boundary conditions. It is found that these values are in good agreement with those of previous investigations leading to the conclusion that the chosen minimal FourierGalerkin expansion is a valid one. Exhibition of chaotic motion in the generalized Lorenz system at the Hopf Rayleigh number is studied. The phase-space plots which indicate a clear-cut visualization of the transition from regular convective motion to chaotic motion in the generalized Lorenz system are presented. Further, existence of a developing region for chaos (mildly chaotic motion) and windows of periodicity are captured using the bifurcation diagrams. It is concluded from the phase-space plots and the bifurcation diagrams that the generalized Lorenz model for certain sets of boundary conditions retains all the features of the classical Lorenz model. Such a conclusion cannot be made by a linear stability analysis and the need thus for a nonlinear analysis is highlighted in the paper. 2020 Elsevier Inc. -
How efficient are public sector banks in India? A non-parametric approach
This study examines the efficiency of Public Sector Banks (PSBs) in India using Data Envelopment Analysis (DEA). Analysis is carried out on a sample of 19 PSBs that are existed during the study period from 2005 to 2018. There are two different aspects deliberated, namely technical efficiency of PSBs and the growth in their productivity. Input variables envisaged for the study are deposits, borrowings, fixed assets, and the number of employees. Loans and advances along with investments act as output variables to measure technical efficiency and productivity. The results indicate that the technical efficiency of PSBs ranges between 97% and 100%. Corporation Bank, Indian Bank, and Oriental Bank of Commerce outperformed their peers with 100% technical efficiency. Productivity growth among the sampled banks during the study period stood between 0.8% and 20%. However, Corporation Bank, Indian Bank, and Oriental Bank of Commerce registered 9.1%, 5.4% and 6.4% productivity growth, respectively. The results reveal that PSBs are working hard to optimize resource utilization. Researchers around the world can use DEA as a tool to measure the efficiency of banks with different input and output variables related to financial, marketing and managerial performance. Sangeetha R., 2020. -
The mediating role of positive perceptions on coping strategies and psychological well-being among mothers of children with intellectual disabilities
Purpose: Research on caregiving has been considering the positive effects experienced by the mothers of children with disabilities. This paper aims to examine whether positive perceptions mediate the relationships between coping strategies used and psychological well-being among mothers of children with intellectual disabilities. Design/methodology/approach: The study opted for a quantitative approach that includes a correlation research design to examine the relationships between the variables of coping, positive perceptions and well-being among mothers of children with intellectual disabilities attending special schools in the metropolitan city Bengaluru, India. The four-factor structure of Brief COPE examined were active avoidance coping, problem-focussed coping, positive coping and religious-denial coping. Positive perceptions refer to the positive contributions for the mother from the experiences of raising a child with intellectual disability. Mediation analysis explored the relationship between the variables. Findings: Problem-focussed coping was the most commonly reported coping factor and was associated with higher levels of well-being. Active-avoidance coping was the least commonly reported coping strategy. Positive perceptions partially mediated the relationship between the four coping factors and maternal well-being. These findings indicate that positive maternal perceptions have important implications for the employment of effective coping strategies that are associated with enhancement of psychological well-being. Originality/value: The focus on positive perceptions would help in understanding the use of coping strategies and planning of support services or interventions. The positive mental health of mothers paves the way for positive developments in the childs physical and psychological health. 2020, Emerald Publishing Limited. -
Stochastic frontier analysis to measure technical efficiency: Evidence from skilled and unskilled agricultural labour in india
This paper comprises the stochastic frontier model which has been applied to measure the technical efficiency of skilled and unskilled labour. By considering the certain input variables listed in the cost of cultivation suggested by the Commission of Agricultural Costs and Prices (CACP) for Indian states during the main cropping season. Result of the study shows that the evaluated average technical efficiency estimates have been found between 71 to 84 % for both type of labour. Factors i.e. use of seeds (77 % efficient), fertilizers (29 % inefficient), manure (3 % efficient), land, human (9 % efficient), attached (10 % efficient) and casual (103 % efficient) labor, animal labor (is between 1 to 4 % efficient), hired machine (33 % inefficient), owned machine (7 % efficient), insecticides (20 % efficient), irrigational cost (31 % efficient), fixed cost (36 % inefficient) and operational cost (197 % inefficient) have a significant at 1, 5 and 10 % level of significance1. 2020 DAV College. All rights reserved. -
Large power factors in wide band gap semiconducting rFeO3 materials for high-temperature thermoelectric applications
While most of the thermoelectric materials work well only at low and mid temperatures, high-temperature thermoelectric materials (T > 900 K) are equally important for the operation of deep-spacecraft missions, nuclear reactors, and high-temperature industrial reactors. To accomplish this demand, this work provides insights into wide band gap semiconducting RFeO3 (rare-earth orthoferrites) for high-temperature thermoelectric applications. Using the first-principles density functional theory calculations, we have demonstrated the coexistence of extremely flat and corrugated flat bands near the Fermi region in a wide band gap material. The presence of such features enhances and sustains the thermopower, electrical conductivity, and power factor, which are the crucial factors for the efficiency of thermoelectric materials. Semiclassical Boltzmann formalism was then employed to study the transport properties of four orthorhombic RFeO3 materials (R = Pr, Nd, Sm, and Gd). Our results reveal high Seebeck coefficients (thermopower) along with the large electrical conductivities over the high hole doping carrier concentration and in the high-temperature region (T > 900 K). Furthermore, significantly large power factors are obtained with very low theoretical minimum lattice thermal conductivity in the range 1.41?1.51 W m?1 K?1. These huge power factors directly suggest the maximum power output in RFeO3, which we believe is a more appropriate performance index than the figure of merit, especially for high-temperature thermoelectric applications. We also emphasize that the outcomes of our work would be certainly useful for experimentalists in designing high-temperature thermoelectric materials. 2020 American Chemical Society -
Extending schizophrenia diagnostic model to predict schizotypy in first-degree relatives
Recently, we developed a machine-learning algorithm EMPaSchiz that learns, from a training set of schizophrenia patients and healthy individuals, a model that predicts if a novel individual has schizophrenia, based on features extracted from his/her resting-state functional magnetic resonance imaging. In this study, we apply this learned model to first-degree relatives of schizophrenia patients, who were found to not have active psychosis or schizophrenia. We observe that the participants that this model classified as schizophrenia patients had significantly higher schizotypal personality scores than those who were not. Further, the EMPaSchiz probability score for schizophrenia status was significantly correlated with schizotypal personality score. This demonstrates the potential of machine-learned diagnostic models to predict state-independent vulnerability, even when symptoms do not meet the full criteria for clinical diagnosis. 2020, The Author(s). -
Benzoyl hydrazine-anchored graphene oxide as supercapacitor electrodes
In this study, benzoyl-hydrazine anchored graphene oxide (BHGO) is synthesised using graphene oxide (GO) and benzoyl hydrazine (BH) via a simple, cost effective ultrasonic assisted chemical route. BH acted as a nitrogen source, reducing agent, and morphology modifier resulting in good electrochemical performance of BHGO. The supercapacitor behaviour of BHGO is investigated in different aqueous electrolytes and it exhibits a specific capacitance of 170 F g?1 at a current density of 1 A g?1 in 1 M H2SO4 and capacitive retention of 85% over 5000 cycles at 5 A g?1. This high performance is attributed to the enrichment of electroactive sites of GO through nitrogen moieties enhancing faradaic redox reactions and thereby the polarization at the electrode surface. 2020 Elsevier B.V. -
Role of supramolecular interactions in crystal packing of Strandberg-type cluster-based hybrid solids
Abstract: Two new Strandberg-type cluster-based phosphomolybdates {H-2a3mp}5[{PO3(OH)}{PO4}Mo5O15], 1 and {H-2a4mp}5[{PO3(OH)}{PO4}Mo5O15]6H2O, 2 have been crystallized via solvent evaporation technique using 2-amino-3-methylpyridine (2a3mp) and 2-amino-4-methylpyridine (2a4mp) respectively. The solids were characterized using single-crystal X-ray diffraction, powder X-ray diffraction, fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy and cyclic voltammetry. The solid 1 crystallized in monoclinic system with space group P21/c, a = 8.394(1), b = 27.398(6), c = 21.521(4) ? = 97.68(3), Z = 4. The solid 2 crystallized in triclinic system with space group P-1, a = 11.728(1), b = 14.234(1), c = 19.589(1) ? = 68.906(3), ? = 89.454(3), ? = 66.559(3), Z = 2. The solids 1 and 2 formed a supramolecular framework stabilized by hydrogen bonding interaction between cluster anions and organic moieties. CH? interactions between the organic moieties reinforced the crystal packing in 1 and 2. While crystal packing effects resulted in the formation of solvent-accessible voids in 1; aggregation of lattice water molecules in 2 facilitated the formation of pentameric water cluster. In addition, electrochemical behavior of 1 and 2 has also been investigated. Graphic abstract: Two new Strandberg-type cluster based phosphomolybdates, 1 and 2 have been crystallized via solvent evaporation technique using 2-amino-3-methylpyridine and 2-amino-4-methylpyridine. Detailed structural analysis revealed the role of supramolecular interactions in the crystal packing of these solids. In addition, electrochemical behavior of 1 and 2 has also been investigated.[Figure not available: see fulltext.] 2020, Indian Academy of Sciences. -
Evaluation of Corrosion Mitigation Performance of 1-(3,4,5-Trimethoxyphenylmethylidene)-2-Naphthylamine (TMPNA) Schiffs Base on Carbon Steel Using Electrochemical, Thermodynamic and Theoretical Approaches
A novel Schiff base,1-(3,4,5-trimethoxyphenylmethylidene)-2-naphthylamine(TMPNA) has been synthesized using naphthylamine and 3,4,5-trimethoxybenzaldehyde.The effective corrosion resistance and inhibition effect of TMPNA was studied at different concentrations in water medium on carbon steel by electrochemical techniques. The protective behavior of the passive film formed by the inhibitor was characterized through electrochemical impedance spectroscopy with an increased charge transfer resistance of 954 ?.cm2. The inhibition efficiency exhibited a gradual increase up to 92% with increase in schiff base concentration. Potentiodynamic polarization studies revealed that corrosion current decreased to 0.35 10?5A/cm2 with the addition of the inhibitor, TMPNA. Through various electrochemical studies such as impedance, polarization and electrochemical noise analysis (ENA), the concentration of TMPNA was optimized to 300ppm at which the maximum corrosion resistance was observed. Inhibition efficiency was found to decrease with increase in temperature. Also, the increased activation energy (Ea) value of 27kJ/mol confirmed that the inhibitor hindered the metal dissolution reaction. Adsorption of TMPNA on carbon steel/electrolyte interface was found to obey Langmuir adsorption isotherm. Scanning electron microscope (SEM) was used to evaluate the surface morphology. The Quantum chemical analysis (QCA) revealed that there was an electron transfer between TMPNA and the metal surface at ? 6.340eV. Molecular dynamic simulation study was carried out to investigate the adsorption of TMPNA on Fe (1 1 0) surface and adsorption energy value for the gaseous form was found to be ? 4197cal/mol. 2020, Springer Nature Switzerland AG. -
A Study of Factors of Internet Addiction and Its Impact on Online Compulsive Buying Behaviour: Indian Millennial Perspective
Compulsive Buying occurs when a person indulges in excessive purchasing overcome by social pressures and negative emotions. The main objective in this study is to garner insights into this issue from a marketing perspective and also to understand whether the millennials preference to avoid social contact physically but to crave for it in a virtual space has an impact. Conducted over a seven-month period with data collected and analyzed from 202 respondents in Bangalore, the study revealed that emotions like loneliness, depression, low self-esteem and anxiety encourage the respondents to go ahead and maintain relationships in a virtual space rather than engage in face-to-face interactions. Furthermore, it was realized that the growing Internet Addiction can also be positively related to online Compulsive Buying. This study is of high significance as it allows marketers to reach out and capture that segment of elusive customers who are always online and are guaranteed to make a purchase. Therefore, allowing companies can align their marketing strategies accordingly develop products and services, resulting in better sales revenues and repeat purchases. 2019 International Management Institute, New Delhi. -
Experimental Investigations on the Thermal Diffusion Characteristics and Photoluminescence in Multiphase Micro Fluids Containing ZnO Micro Tubes and Fluorescein Dye
Abstract: Scattering of light by disordered structures is normally detrimental to their applicability in many optoelectronic devices. However, some micro and nanostructures are useful in enhancing several optical and thermal properties like emission, heat diffusion etc. For this purpose, we have optimized the low temperature hydrothermal growth method for the ZnO micro tubes which leads to the growth of ZnO as mono dispersed micro tubes. Further, these samples were used to enhance the fluorescence efficiency of disordered media consisting of micro tubes of ZnO and fluorescein dye and to optimize the thermal diffusion of the mixture which will help us optimize the composition of these microscopic inclusions in designing a random lasing medium. Dual beam thermal lens method was used for this purpose. 2020, Pleiades Publishing, Ltd. -
Yulu: Moving Towards a Sustainable Future
The rapidly rising rate of urbanization, which is closely linked to economic growth, has exposed the world to several challenges such as inequality, environmental degradation, traffic congestion, infrastructural concerns and social conflicts. Therefore, urban sustainability has emerged as one of the most debatable discussions across the world. The existing network of transportation can no longer keep up with the growing demand in metropolitan cities. Short distance travel has become an unresolved issue for daily commuters. The case presents how MMVs have emerged as an alternative mode of transport for resolving issues of daily commuters regarding the first-mile connectivity, last-mile connectivity and short distance travel to reach their final destination. MMVs are basically light-weight vehicles which occupy less space on road. These vehicles include bicycles, e-bikes, skateboards, hoverboards and other battery-operated vehicles. The case narrates the journey of Yulu, a dockless bike-sharing venture which promoted the concept of green consumerism among the daily commuters at affordable rates. The venture initially started in the IT city of Bangalore and later expanded its operations to other cities such as Pune, Navi Mumbai, Gurugram and Bhubaneswar. The speciality of this venture is that it offers a sustainable solution to ever-increasing problems of traffic congestion and aggravating air pollution issues in metropolitan cities. Dilemma: How to offer a sustainable solution to the ever-increasing problem of traffic congestion and aggravating air pollution due to rising vehicular traffic? How to make short distance travel affordable and more convenient for daily commuters? Theory: Three pillars of sustainable development. Type of Case: Problem solving applied case. Protagonist: Present. Discussion and Case Questions: What strategies should be employed by the start-up to make it a more popular form of commute? How can the increasing rate of damage to the vehicles be brought down? How does organization structure and cluster management practices of Yulu help it to become more sustainable? How can the regulatory bodies and government promote and adopt such start-ups in their urban planning projects? 2020 SAGE Publications. -
Humour as a moderator of stress and defence based coping mechanisms among the youth of Kerala, India
The goal of this study was to examine the effect of the moderators of adaptive and maladaptive humour on stress and on the four levels of defence based coping mechanism amongst the youth of Kerala, India. Four hundred and fifty-three youth between the age of 18 and 40, selected from two different cities of North Kerala, India (Calicut, Malappuram) and Central Kerala, India (Cochin, Trissur), were asked to fill out three questionnaires assessing stress, coping and humour. Pearson's test of product-moment correlation indicated that stress had a positive and moderate statistically significant correlation with the first three levels of defence based coping mechanism (pathological defences, immature defences and neurotic defences). Furthermore, there was a positive and weak statistically significant correlation between stress and level-IV coping (mature defences). When positive and moderate correlation was found for stress with maladaptive humour, no significant correlation was found with adaptive humour. When coping was studied in relationship with humour, a negative and weak statistically significant correlation was found for level-I coping (pathological defences) with adaptive humour, whereas a positive and moderate statistically significant correlation was found with maladaptive humour. Here level-IV coping (mature defences) was found to have a positive and moderate statistically significant relationship with adaptive and maladaptive humour. Moderator analysis showed that maladaptive humour moderated the association between stress and four levels of defence based coping mechanism. The study implied that youth should be trained to use more of mature means of coping and adaptive humour styles in life. Universiti Putra Malaysia Press -
A hybridized semantic trust-based framework for personalized web page recommendation
The World Wide Web is constantly evolving and is the most dynamic information repository in the world that has ever existed. Since the information on the web is changing continuously and owing to the presence of a large number of similar web pages, it is very challenging to retrieve the most relevant information. With a large number of malicious and fake web pages, it is required to retrieve Web Pages that are trustworthy. Personalization of the recommendation of web pages is certainly necessary to estimate the user interests for suggesting web pages as per their choices. Moreover, the Web is tending towards a more organized Semantic Web which primarily requires semantic techniques for recommending the Web Pages. In this paper, a framework for personalized web page recommendation based on a hybridized strategy is proposed. Web Pages are recommended based on the user query by analyzing the Web Usage Data of the users. An array of strategies is intelligently integrated together to achieve an efficient Web Page Recommendation system. Latent Semantic Analysis is applied to the User-Term Matrix and the Term-Frequency Matrix that are built from the Web Usage Information to form a Term Prioritization Vector. Further, techniques like Latent Dirichlet Allocation for Topic-based Segregation of the URLs and Normalized Pointwise Mutual Information strategies are used for recommending web pages based on users queries. The Personalization is achieved by prioritizing the Web pages based on the Prioritization Vector. Also, a unique methodology is incorporated into the system to retrieve trustworthy websites. An overall Accuracy of 0.84 is achieved which is better than the existing strategies. 2018 Informa UK Limited, trading as Taylor & Francis Group. -
Facile synthesis of nickel nanoparticles and its efficient dye degradation
The present investigation involves the synthesis of nickel (Ni) nanoparticles (NPs) by the chemical reduction of nickel chloride using hydrazine hydrate without the need for an inert atmosphere from an external source. The photocatalytic activity, structure and morphology of the NPs were studied by employing UV-Visible (UV-Vis) spectroscopy, powder X-ray diffraction (PXRD) and transmission electron microscopy (TEM). Degradation of methylene blue(MB) and rhodamine B(Rh-B) dyes using Ni NPs was investigated to see the feasibility in degrading these dyes from polluted water at low cost. Ni NPs showed a good photocatalytic activity of 84.1% under visible light for the degradation of MB when compared to Rh-B which showed an efficiency of 47.3 %. 2020 World Research Association. All rights reserved. -
Preparation, characterization, and evaluation of corrosion inhibition efficiency of sodium lauryl sulfate modified chitosan for mild steel in the acid pickling process
The polar head and a hydrophobic long alkyl chain end of surfactants show effective adsorption on the metal surfaces and metal/solution interfaces. The present study deals with the investigation of corrosion inhibition efficiency of chitosan modified with an anionic surfactant, namely sodium lauryl sulfate. The modified chitosan was characterized using spectral techniques such as ATR- FTIR and NMR, thermal analytical methods that include TGA and DSC. The surface charge and particle size distribution were analyzed using Zeta potential analyzer. The corrosion inhibition efficiency of the water-soluble modified chitosan was evaluated using gravimetric and electrochemical methods. A maximum corrosion inhibition efficiency of 96.44% for 6 h of immersion period at 303 K was obtained. The adsorption process obeyed Langmuir isotherm. The adsorption mechanism involved both physisorption and chemisorption. Tafel and impedance studies showed results in agreement with the gravimetric method. Tafel plot indicates the inhibitor controlled both cathodic hydrogen evolution and anodic metal dissolution reactions. AC impedance study supports the increase in surface coverage of the metal surface by the inhibitor, forming a protective film. Further evidence comes from the surface characterization of the inhibited metal surface by contact angle measurement, SEM, EDAX spectra, and atomic force microscopic studies. DFT and Monte Carlo simulation studies showed a proper alignment with the experiment results. 2020 Elsevier B.V.