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Effects of dark matter in red giants
Dark matter (DM) which constitutes five-sixths of all matter is hypothesized to be a weakly interacting non-baryonic particle, created in the early stages of cosmic evolution. It can affect various cosmic structures in the Universe via gravitational interactions. The effect of DM in main sequence stars and stellar remnants like neutron stars and white dwarfs has already been studied. Red giant phase is a late stage of the evolution of stars. In this work, we study, low-mass red giants stars with admixture of DM and how this can effectively change the intrinsic properties of red giants such as their luminosities, temperatures and lifetimes. 2020 Elsevier B.V. -
Structural, luminescence and NMR studies on Nd3+-doped sodiumcalcium-borate glasses for lasing applications
In this work, Neodymium (Nd3+) -doped borate glasses were synthesised by melt-quenching method and their structural as well as optical properties were analysed through XRD, Raman, NMR, DSC, UVVisible, luminescence and decay studies for the possible application as laser gain medium. DSC and XRD results revealed that the glasses have high transition temperature and are in amorphous nature, respectively. The vibrational characteristics of the host matrices as well as the effect of Nd3+ incorporation were analysed by using Raman spectra, which exhibit majorly borate groups as supported by NMR results. The band gap energy of the glasses decreases with an increase in Nd3+ concentration. Using Judd-Oflet theory the characteristic intensity parameters (??, ? = 2, 4 and 6) were calculated and further used for calculating the various radiative parameters from the emission spectra. The emission cross-section (?em) was estimated as high as 1.15 10?20 cm2 from the FhtbauerLandenburg (FL) equation for the dominant 4F3/2?4I11/2 (1056 nm) transition. The effect of Nd3+ concentration on the lifetime of the 4F3/2 luminescent level was analysed from the decay curve analyses. From which, the corresponding quantum efficiency (?) was estimated and found as high as 54%. The investigated result suggests the prepared glasses can be utilized as gain medium to generate laser at around 1.05 ?m. 2020 Elsevier Ltd and Techna Group S.r.l. -
Structural and physico-chemical evaluation of melatonin and its solution-state excited properties, with emphasis on its binding with novel coronavirus proteins
Melatonin is a natural hormone from the pineal gland that regulates the sleep-wake cycle. We examined the structure and physico-chemical properties of melatonin using electronic structure methods and molecular-mechanics tools. Density functional theory (DFT) was used to optimise the ground-state geometry of the molecule from frontier molecular orbitals, which were analysed using the B3LYP functional. As its electrons interacted with electromagnetic radiation, electronic excitations between different energy levels were analysed in detail using time-dependent DFT with CAM-B3LYP orbitals. The results provide a wealth of information about melatonin's electronic properties, which will enable the prediction of its bioactivity. Molecular docking studies predict the biological activity of the molecules against the coronavirus2 protein. Excellent docking scores of ?7.28, ?7.20, and ?7.06 kcal/mol indicate that melatonin can help to defend against the viral load in vulnerable populations. Hence it can be investigated as a candidate drug for the management of COVID. 2020 Elsevier B.V. -
Thermoconvective instability in a vertically oscillating horizontal ferrofluid layer with variable viscosity
The paper sheds light on the linear and nonlinear stability of a ferrofluid with the temperature and magnetic-field-dependent viscosity subjected to an imposed time-periodic gravity modulation. The perturbations in the system due to external reasons are expanded in terms of the amplitude of modulation in the case of linear stability and a truncated representation of the Fourier series in the case of nonlinear stability. A nonautonomous Lorenz model for the problem is first obtained, and both linear and nonlinear analyses of the system are performed using this. The expression for the critical Rayleigh number, (Formula presented.), and the correction Rayleigh number, (Formula presented.), is found from the linearized Lorenz model. The Lorenz system of equations is solved for the amplitude to arrive at the Nusselt number (Nu), which quantifies the heat transport. In the study we find that the thermorheological effect and the magnetization effect work in unison to destabilize the system, while the magnetorheological effect and the effect of vertical oscillations stabilize the system. The influence of the parameters on the heat transport is the opposite to their effect on the critical Rayleigh number. The results of the paper agree quite well with those of limiting cases. 2020 Wiley Periodicals LLC -
A novel assessment of bio-medical waste disposal methods using integrating weighting approach and hesitant fuzzy MOOSRA
Bio-medical waste (BMW) management is highly important precaution for human health and environmental concern. There are several disposal treatment followed by medical practitioners in medical waste management. Here, a few disposal treatment is considered to be an alternatives. When assessing, it is necessary to evaluate and assume that all disposal treatment methods are safe and hygienic. In this way, every alternative assessment is evaluated based on the social acceptance, technology and operation, environmental protection, cost, noise and health risk. Finally the best alternative is chosen. When BMW is disposed and we select the best treatment method in BMW management, it can lead to multi-criteria decision making (MCDM) processes related to uncertain critical assessments. When making a decision, the decision makers having some hesitation to give their suggestions. Therefore, here we use hesitant MCDM method. In today's practice we have choose five methods of BMW disposal methods used in the medical world and we have its alternatives. One of these alternative is sorted by six criteria weights for selecting the best method. The main aim of this research paper is propose a new methodology of hesitant fuzzy weight finding technique, it is named as Hesitant Fuzzy Subjective and Objective Weight Integrated Approach (HF-SOWIA) and also propose a new hesitant fuzzy rank finding methodology, it is named as Hesitant Fuzzy Multi-Objective Optimization on the basis of Simple Ratio Analysis (HF-MOOSRA). After evaluation, the result shows that autoclaving is the best alternative for BMW disposal treatment methods. Furthermore, sensitivity analysis is make in order to observe the difference of alternative ranking when the importance of subjective and objective weights changes. 2020 Elsevier Ltd -
Relating the role of green self-concepts and identity on green purchasing behaviour: An empirical analysis
At present, consumers in emerging economies are becoming more conscious about environmental well-being. Therefore, organizations compete to make their products and practices more eco-friendly. Several studies have tried to explain the relationship between green consumerism and an individual's buying behaviour using traditional theories. However, there is quite a challenge in understanding the influence of green self-concept (GSC) and green self-identity (GSI) in predicting the green purchase intention (GPI) of consumers. Therefore, the authors developed six hypotheses to assess the relation between self-concept and the GPI. The survey was conducted, and the responses were evaluated through the partial least square (PLS) method. The authors analysed the measurement model results (n = 717) and the direct and indirect mediating effect of the latent variable contributing to GPI. The measurement model results show that a significant relationship exists in the proposed model, namely, GSCs ? green purchasing intentions, product self-concept (PSC) ? green purchasing intentions and GSI ? green purchasing intentions. Further, the GSI acted as a mediator for the measurement model. The implications of the study can be used to understand the green consumer behavior in developing new strategies and policies for the organizational practice in emerging economies. 2020 ERP Environment and John Wiley & Sons Ltd. -
Education for All: How Schooling Is Creating Social Changes for Lowered-Caste Girls in Rural India
Arguments for the expansion of formal schooling have long focused on individual outcomes from schooling, including increasing income, reducing poverty, delaying marriage, and improving health, particularly for girls and women. For nearly three decades now, global education agendas have supported girls education in an effort to achieve these outcomes. A large body of research analyzes girls individual empowerment from schooling, but less attention is given to how schooling is creating change in families and communities, particularly for lowered-caste girls in India. This article places longitudinal data from a three-year qualitative interview study of schoolgirls in Rajasthan alongside qualitative life-history interviews of girls who completed secondary school in Uttarakhand to understand how schooling affects social changes for lower castes. The analysis, using an intersectional and relational approach, illustrates how girls schooling shifts kin and caste relations connected to marriage and work but in ways that do not transform the stickiness of caste and gender norms. We argue that educational policies and programs must attend to the ways in which caste is implicated in achieving outcomes of delayed marriage and formal employment for lowered-caste girls in Indian communities if schooling is to create positive social change. 2020 by The Author(s). -
Sentiment Analysis of COVID-19 tweets by Deep Learning ClassifiersA study to show how popularity is affecting accuracy in social media
COVID-19 originally known as Corona VIrus Disease of 2019, has been declared as a pandemic by World Health Organization (WHO) on 11th March 2020. Unprecedented pressures have mounted on each country to make compelling requisites for controlling the population by assessing the cases and properly utilizing available resources. The rapid number of exponential cases globally has become the apprehension of panic, fear and anxiety among people. The mental and physical health of the global population is found to be directly proportional to this pandemic disease. The current situation has reported more than twenty four million people being tested positive worldwide as of 27th August, 2020. Therefore, it is the need of the hour to implement different measures to safeguard the countries by demystifying the pertinent facts and information. This paper aims to bring out the fact that tweets containing all handles related to COVID-19 and WHO have been unsuccessful in guiding people around this pandemic outbreak appositely. This study analyzes two types of tweets gathered during the pandemic times. In one case, around twenty three thousand most re-tweeted tweets within the time span from 1st Jan 2019 to 23rd March 2020 have been analyzed and observation says that the maximum number of the tweets portrays neutral or negative sentiments. On the other hand, a dataset containing 226,668 tweets collected within the time span between December 2019 and May 2020 have been analyzed which contrastingly show that there were a maximum number of positive and neutral tweets tweeted by netizens. The research demonstrates that though people have tweeted mostly positive regarding COVID-19, yet netizens were busy engrossed in re-tweeting the negative tweets and that no useful words could be found in WordCloud or computations using word frequency in tweets. The claims have been validated through a proposed model using deep learning classifiers with admissible accuracy up to 81%. Apart from these the authors have proposed the implementation of a Gaussian membership function based fuzzy rule base to correctly identify sentiments from tweets. The accuracy for the said model yields up to a permissible rate of 79%. 2020 Elsevier B.V. -
Cation-controlled wetting properties of vermiculite membranes and its promise for fouling resistant oilwater separation
Manipulating the surface energy, and thereby the wetting properties of solids, has promise for various physical, chemical, biological and industrial processes. Typically, this is achieved by either chemical modification or by controlling the hierarchical structures of surfaces. Here we report a phenomenon whereby the wetting properties of vermiculite laminates are controlled by the hydrated cations on the surface and in the interlamellar space. We find that vermiculite laminates can be tuned from superhydrophilic to hydrophobic simply by exchanging the cations; hydrophilicity decreases with increasing cation hydration free energy, except for lithium. The lithium-exchanged vermiculite laminate is found to provide a superhydrophilic surface due to its anomalous hydrated structure at the vermiculite surface. Building on these findings, we demonstrate the potential application of superhydrophilic lithium exchanged vermiculite as a thin coating layer on microfiltration membranes to resist fouling, and thus, we address a major challenge for oilwater separation technology. 2020, The Author(s). -
Development and Validation of Emotion Recognition Software in the Indian Population
Though written extensively, recent debates on universality of emotions have shown that age, gender, and ethnicity have greater implications in the ability to identify expressions from faces. Facial emotion recognition deficits have been consistently shown in psychiatric conditions, which necessitates the need to construct a culturally sensitive tool. Fourteen actors depicted emotions such as happy, sad, anger, fear, surprise, disgust, and neutrality. From a total of 126 images, participants rated in terms of intensity and accuracy. Final software was developed with 28 images, and mean accuracy and reaction time were obtained. Friedmans significance test revealed a significant effect of emotion on its different dimensions. This study helped establish a culturally sensitive emotion recognition tool with the Indian population, which can be used in mental health settings for screening purposes and aid in developing rehabilitation modules. 2020, National Academy of Psychology (NAOP) India. -
An organocatalytic C-C bond cleavage approach: A metal-free and peroxide-free facile method for the synthesis of amide derivatives
A facile organocatalytic approach has been devised towards the synthesis of amide derivatives using 1,3-dicarbonyls as easily available acyl-sources under peroxide-free reaction conditions. This transformation was accomplished by the cleavage of the C-C bond in the presence of TEMPO as an organocatalyst and excludes the use of transition-metals and harsh reaction conditions. A broad range of substrates with diverse functional groups were well tolerated and delivered the products in high yields. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique. -
Investigation on Electrode/Electrolyte Interfaces through Impedance Spectroscopy
In the present paper, impedance measurements of the battery configuration, Anode?lithium borophosphate glass electrolyte?LiCoO2 cathode, has been carried out to throw some light on the electrochemical interfacial behavior between the chosen electrodes and electrolyte. The cathode material, lithium cobalt oxide (LiCoO2) has been prepared by three different techniques and characterized. Sol-gel synthesized LiCoO2 showed uniformly distributed spherical shape particles with an average size of 500 nm and also exhibited better electrochemical performance. Charging and discharging (23 cycles) of the battery indicated an OCV of 2 V. However, the theoretical OCV of 4 V could not be achieved. The poor performance of the battery could be attributed to the electrochemical processes and SEI film formation at the electrode/electrolyte interfaces. Impedance spectroscopy shows that the major contributions to the impedance of the battery are the electrolyte resistance and the electrode/electrolyte interfacial resistance. With each recharging cycle, the value of electrolyte resistance remains almost constant; however, the interface resistance increases, during the passage of current, due to the interfacial passive layer formation. 2020 Taylor & Francis Group, LLC. -
A Note on J-colouring of Jahangir Graphs
In this paper, we discuss J-colouring of the family of Jahangir graphs.Note that the family of Jahangir graphs is a wide ranging family of graphs which by a generalised definition includes wheel graphs. We characterise the subset of Jahangir graphs which admit a J-colouring. 2019, The National Academy of Sciences, India. -
Natural convection of water-copper nanoliquids confined in low-porosity cylindrical annuli
Natural convection in cylindrical porous annuli saturated by a nanoliquid whose inner and outer vertical radial walls are respectively subjected to uniform heat and mass influxes and out fluxes is studied analytically using the modified Buongiorno-Darcy model (MBDM) and the Oseen-linearization technique. Nanoliquid-saturated porous medium made up of water as base liquid, copper nanoparticles of five different shapes, viz., spheres, bricks, cylinders, platelets and blades, and glass balls porous material is considered as working medium for investigation. The thermophysical properties of nanoliquid -saturated porous medium is modeled using phenomenological laws and mixture theory. The effect of various parameters and individual effects of five different shapes of copper nanoparticles on velocity, temperature and heat transport are found. From the study, it is clear that the addition of a dilute concentration of nanoparticles increases the effective thermal conductivity of the system and thereby increases the velocity and the heat transport, and decreases the temperature. In other words, the heat transport is more in the case of heat and mass driven convection compared to purely heat-driven convection. Among the five different shapes of nanoparticles, blade-shaped nanoparticles facilitate the transport of maximum temperature compared to all other shapes. Maximum heat transport is achieved in a shallow cylindrical annulus compared to square and tall circular annuli. The increase of the inner solid cylinder's radius is to decrease heat transport. The results of the KVL single-phase model are obtained from the present study by setting to zero the value of the nanoparticles concentration Rayleigh number. Also, neglecting the curvature effect in the present problem, we obtain the results of the rectangular enclosure problem. 2020 The Physical Society of the Republic of China (Taiwan) -
Experimental investigation of turbulent flow behavior in an air to air double pipe heat exchanger using novel para winglet tape
Double pipe Heat exchangers are some of the important equipment which is seen in a variety of industrial applications. In the current study a new type of insert, namely Para-Winglet Tape inserts are investigated for thermal and flow behavior from Reynolds number 6000 to 30000. The Para-Winglet Tape inserts are investigated for three sets of pitches and para-inclinations. The inclusion of para-winglet tape on the tube has intensified the turbulent kinetic energy and has resulted in recirculation in-between the inserts. The arrangement of the para-winglet tape has proved their worthiness over the plain tube. The highest Nusselt number was obtained for Case9 at Reynolds number 30000 with an enhancement of 407% and the least was obtained by Case7 at Reynolds number 6000 with an enhancement of 88% compared to plain double pipe heat exchanger. The highest friction factor was obtained for Case3 at Reynolds number 30000 with an enhancement of 846% and the least was obtained by Case7 at Reynolds number 24000 with an enhancement of 286% compared to plain double pipe heat exchanger. The maximum and minium performance optimization index value of 2.69 and 1.09 was achieved for Case9 and Case1 at Reynolds number 30000 and 6000. 2020 The Author(s). -
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. -
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. -
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. -
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 -
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.