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Rayleigh-Bard Convection of Water-Copper and Water-Alumina Nanofluids Based on Minimal- and Higher-Mode Lorenz Models
Linear and nonlinear stability analyses of Rayleigh-Bard convection in water-copper and water-alumina nanofluids are studied in the paper by considering a minimal as well as an extended truncated Fourier representation. These representations respectively result in a third-order classical Lorenz model and a five-dimensional extended Lorenz model. The marginal stability plots reveal that the influence of added dilute concentration of nanoparticles in water is to destabilize the system. The rate of destabilization depends on the nanoparticles' thermophysical properties and their volume fraction. Influence of adding an additional mode in the horizontal direction is to modify the cell size. This can be observed through the marginal curves as well as the stream line plots. Further, from the Nusselt number plots it is evident that the presence of dilute concentration of nanoparticles in water is to enhance heat transport in the system significantly. The dynamical behavior of the minimal and the extended Lorenz models is investigated using the bifurcation diagram. From the study an important finding that emerges is that the Fourier truncated solution is predicted to have different effects in lower-order and higher-order models. The extended penta-modal Lorenz system predicts advanced onset of chaos compared to that predicted by the classical third-order Lorenz model. The individual influence of both nanoparticles in water is to advance the onset of convection as well as to advance the onset of chaos. 2023 World Scientific Publishing Company. -
Risk Behavior Among Emerging Adults: The Role of Adverse Childhood Experiences (ACE), Perceived Family and Interpersonal Environment
Background: Evidence demonstrates that ambiance provided during childhood and the interactions of children with different social agents during childhood have an impact on their adult behaviour. Objective: The current research tries to explore the role of adverse childhood experiences and perceived family and interpersonal interactions in their resultant adult risk behaviour. Method: Around 613 emerging adults (1824 years; Male 343 and Female 270) from the northern districts of Kerala, India took part in the study. The participants were selected using multistage sampling techniques. A Semi-structured Questionnaire was used to understand the perceived family and interpersonal environment. In addition, a checklist (adopted from the risk behaviour scale and youth risk behaviour survey) was also employed. The checklist assisted to understand the presence of actual risk behaviours. Results: Hierarchical Logistic Regression analysis is used to test the hypotheses. The results revealed that 87.2 % of the participants were engaged in at least one type of risk behaviour. Socio-demographic variables (gender and family type) and items of perceived family and interpersonal relationships and adverse childhood experiences were found to be significant predictors of emerging adult risk behaviour. Conclusion: The results further highlight the significance of childhood experiences and the current family environment of emerging adults in understanding their behaviour, and in designing evidence-based intervention program for emerging adults. 2023 The Author(s). -
Hydrothermally synthesized mesoporous Co3O4 nanorods as effective supercapacitor material
Mesoporous Co3O4 nanomaterial in rod-shape morphology has been synthesized via a hydrothermal method, and heat treated at 350 C for 2 h to develop a phase. Phase purity, morphology, specific surface area and chemical composition of as-obtained Co3O4 material were studied using XRD, Raman, TEM, N2-adsoprtion/desorption and XPS techniques. XRD and Raman analyses indicate single phase material formation with nano-structure, and cubic normal spinel-type structure with a cell parameter of 8.123 The spinel particles are of rod-shape morphology and the specific surface area, estimated through BET studies, is obtained as 47 m2/g. Cyclic voltammogram (CV) recorded at different scan rates evidently demonstrate pseudocapacitance nature of the synthesized material. Maximum specific capacitance (CS) is computed and the value is 261 F/g at 0.25 A/g. These materials have shown longer cycle stability at lower KOH concentration and lower current density. Synthesized Co3O4 nanomaterial could be used as electrode material for energy storage applications. 2023 Elsevier B.V. -
Occupational stress and psychological wellbeing during COVID 19: Mediating role of positive psychological capital
The COVID 19 pandemic has challenged the humankinds livelihood, physical health, mental health, employment, and economy. Lockdowns, quarantines, online teaching, and learning have become new normal. Negativities have been spread across the globe and society by the pandemic. The negative effects caused a confused mindset, fear, anxiety, stress, and other psychological complications amongst the people especially among the Health Care Workers (HCWs), children, elderly people, and Frontline Workers (FLWs). This research work examines the levels of Occupational Stress (OS), and psychological well-being (PWB) of HCWs and police personnel during the pandemic and the relationship between OS and PWB. Further, the study analyzed the role of Positive Psychological Capital (PPC) as a mediator and Emotional Quotient (EQ) as a moderator in the relationship between OS and PWB. Positive Psychological Capital (PPC) characteristics of the respondents such as having faith in one's ability, and performance, willingness to succeed or attain the goals framed, ability to bounce back from the hard times, and their optimism about the future have helped them to tackle the stress caused by the pandemic and to maintain a better state of psychological wellbeing in the fight against the pandemic. 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature. -
Impact of Abuse on Mental Health and Happiness Among Students: Mediating Role of Family Environment
Background: Child abuse and neglect is an issue of concern for public health professionals. The impact of abuse may lead to poor physical and mental health conditions. Family environment may impact coping and recovery among victims of abuse. The association between child abuse, mental health, happiness, and family environment is complex. The study examines the association and pathways between child abuse exposure, mental health and happiness, while exploring the potentially mediating effect of the family environment. Methods: Data were collected from 571 high school students from Kerala, India, by using various tools, including a semi-structured questionnaire, Depression and Anxiety Youth Scale, and happiness scale. A mediation analysis using structural equation modeling (SEM) was carried out to test the objectives of the study. Results: The analysis shows that mental health, happiness, and family environment are correlated with abuse experience. The mediation analysis further shows that the indirect effect of abuse on mental health via the family environment was significant (? = 0.013, 95% CI [0.002, 0.033]). The indirect effect of abuse on happiness via the family environment was significant (? = 0.019, 95% CI [0.044, 0.003]). Furthermore, the total effect of abuse on mental health (? = 0.266, 95% CI [0.164, 0.354]) and abuse on happiness (? = 0.152, 95% CI [0.259, 0.050]) was significant. Conclusion: The study reveals that abuse experiences impact happiness and mental health outcomes among students. The family environment mediates the relationship between child abuse and mental health, and between child abuse and happiness. 2023 The Author(s). -
Linkage Between Brand Value and Firm Performance: An Empirical Examination Using Fuzzy Set Qualitative Comparative Analysis
This study is designed with the data of Interbrand for ranking top 100 global brands. In this study, the linkage between brand values and financial performance was estimated using different performance measures that include both stock market and operating performance using Fuzzy Set Qualitative Comparative Analysis (fsQCA) technique. The study investigates the effect of brand value on profitability and shareholder. It is observed that the firms that have superior operating performance result in greater brand valuation. Performance of firms measured through profitability is found to be a significant factor in brand valuation. Brand valuation is also found to be significant determinant of profitability. Thus, higher brand quality improves the likelihood of repurchases and in turn improved cash flows. Firms with high agency conflicts tend to have lower brand value. Higher market valuation positively impacts brand valuation in the context of lower leverage and agency costs. The linkage of brand value to firm performance is the justification for marketers investments toward branding initiatives as a mechanism that creates value. This study is the first of its kind to examine the impact of agency costs on brand value using fsQCA technique to understand valuation impact of brands. To measure the effect of branding and marketing initiatives of the firms on financial performance, this study integrated both econometric and financial modeling. The Author(s) 2023. -
Spatio-temporal Crime Analysis and Forecasting on Twitter Data Using Machine LearningAlgorithms
The concept of social media began to gain popularity in the late 1990s and has played a significant role in connecting people across the globe. The constant addition of features to old social media platforms and the creation of new ones have helped amass and retain an extensive user base. Users could now share their views and provide detailed accounts of events from worldwide to reach like-minded people. This led to the popularization of blogging and brought into focus the posts of the commoner. These posts began to be verified and included in mainstream news articles bringing about a revolution in journalism. This research aims to use a social media platform, Twitter, to classify, visualize, and forecast Indian crime tweet data and provide a spatio-temporal view of crime in the country using statistical and machine learning models. The Tweepy Python module's search function and '#crime' query have been used to scrape relevant tweets under geographical constraints, followed by substring-keyword classification using 318 unique crime keywords. The Bokeh and gmaps Python modules create analytical and geospatial visualizations, respectively. Time series forecasting of crime tweet count is performed by comparing the accuracy of Long Short-Term Memory (LSTM), Auto-Regressive Integrated Moving Average (ARIMA), and Seasonal Auto-Regressivee Integrated Moving Average (SARIMA) models to determine the best model. 2023, The Author(s), under exclusive licence to Springer Nature Singapore Pte Ltd. -
Fake News Detection Using TF-IDF Weighted with Word2Vec: An Ensemble Approach
Social media platforms' utilization for news consumption is steadily growing due to their accessibility, affordability, appeal, and ability to propagate misinformation. False information, whether intentionally or unintentionally created, is being disseminated across the internet. Certain individuals spread inaccurate information on social media to gain attention, financial benefits, or political advantage. This has a detrimental impact on a substantial portion of society that is heavily influenced by technology. It is imperative for us to develop better discernment in distinguishing between fake and genuine news. In this research paper, we present an ensemble approach for detecting fake news by using TF-IDF Weighted Vector with Word2Vec. The extracted features capture specific textual characteristics, which are converted into numerical representations for training the models and balanced dataset with the Random over Sampling technique. The implementation of our proposed framework utilized the ensemble approach with majority voting which combines 2 machine learning models like Random Forest and Decision Tree. The proposed strategy was adopted empirically evaluated against contemporary techniques and basic classifiers, including Gaussian Nae Bayes, Logistic Regression, Multilayer Perceptron, and XGBoost Classifier. The effectiveness of our approach is validated through the evaluation of the accuracy, F1-Score, Precision, Recall, and Auc curve, yielding an impressive accuracy score of 94.24% on the FakeNewsNet dataset. 2023, Ismail Saritas. All rights reserved. -
Critical point equation on almost f-cosymplectic manifolds
Purpose: Besse first conjectured that the solution of the critical point equation (CPE) must be Einstein. The CPE conjecture on some other types of Riemannian manifolds, for instance, odd-dimensional Riemannian manifolds has considered by many geometers. Hence, it deserves special attention to consider the CPE on a certain class of almost contact metric manifolds. In this direction, the authors considered CPE on almost f-cosymplectic manifolds. Design/methodology/approach: The paper opted the tensor calculus on manifolds to find the solution of the CPE. Findings: In this paper, in particular, the authors obtained that a connected f-cosymplectic manifold satisfying CPE with \lambda=\tilde{f} is Einstein. Next, the authors find that a three dimensional almost f-cosymplectic manifold satisfying the CPE is either Einstein or its scalar curvature vanishes identically if its Ricci tensor is pseudo anti?commuting. Originality/value: The paper proved that the CPE conjecture is true for almost f-cosymplectic manifolds. 2021, H. Aruna Kumara, V. Venkatesha and Devaraja Mallesha Naik. -
Filamentous fungi for pharmaceutical compounds degradation in the environment: A sustainable approach
Pharmaceutical compounds play an important role in enhancing the quality of human life. They substantially increase the life expectancy of humans and the well-being of livestock. The expansion in the global human population has increased the usage of pharmaceuticals in an enormous way. This has led to the emergence of pharmaceutical compounds as environmental pollutants because these components are continuously released to various water sources and terrestrial ecosystems. The pharmaceutical components are released during their synthesis, as waste from human and veterinary healthcare sectors, and dumping of drugs that are not used. Pharmaceutical components are known to persist in their potential even at lower concentrations and can create serious issues for ecosystems, especially aquatic systems. Various efforts are being made to remove or reduce the toxicity of pharmaceutical components in aquatic systems. Bioremediation using fungi is one of the most secure and sustainable ways of decontaminating polluted environments. With their strong morphology and diverse metabolic abilities, Fungi employ different methods including fungal enzymes to clear pollutants. Studies have proven that fungi and fungal enzymes can transform these pharmaceutical compounds into less toxic components. This review highlights the role of fungi in the bioremediation of pharmaceutical compounds. 2023 The Author(s) -
Environmental cost of food wastage: Integrated response through a mix of environmental policy instruments
Food, when wasted, reaches landfills and emits greenhouse gases. The impact of greenhouse gases (GHGs), in turn, is felt by even those who do not waste food in the place. Externalities thus created are known to distort market efficiency and the most widely discussed externality is climate change. This study takes the case of United States of America (USA) to ascertain the GHGs resulting due to food wastage. The difference between cost per capita due to emissions from animal-based products and emissions from plant-based products comes out to be $122. In the year 1997 total GHG emission for the entire population of the USA due to food wastage was 401.98 billion kgCO2eq, costing the country 45.42 billion US dollars. Two decades later, in 2017, the food waste costs went up by 6 billion US dollars amounting to 51.14 billion US dollars and 452.64 billion kgCO2eq of GHG emissions The novelty of this research lies in highlighting the carbon footprints of food wastage in terms of GHG's and monetizing these emissions. The study proposes an integrated response through a mix of environmental policy instruments of economic incentives, command and control and moral suasion. 2023 ERP Environment and John Wiley & Sons Ltd. -
Enhanced Battery Life with Supercapacitor Applied to Renewable Energy Based Electric Vehicles
The main goal of this work is of developing a control approach, which is able to obtain the smooth switching between energy sources, battery, and Supercapacitor (SCAP). With four separate math functions, a new math function-based (MFB) controller is designed, and this MFB will generate four output signals corresponding to the motor's speed. Further, the MFB is combined with an FLC/PI controller to reach the theme of the work. Two-hybrid different controllers are intended as per the proposed control strategy termed as MFB with FLC and MFB with PI and both are implemented individually in MATLAB/Simulink in four different modes. The entire model is implemented including a solar panel to charge the battery, this solar panel (SP) is connected to the battery and UDC through various control switches. Finally, a comparative analysis is made between two hybrid controllers to know the better-performed controller. 2023 Ecole Polytechnique de Montreal. All rights reserved. -
Design and validation of the digital well-being scale
As the reliance on digital products and services continues to increase, there arises the need to measure and understand how the use of digital devices affects our well-being. In order to do so, the researchers attempted to create and validate an instrument. The items for the instrument were identified through an extensive review of literature, followed by a brainstorming session. The statements were then validated by a panel of experts, post which the instrument was administered, and the data was collected and analyzed for reliability and validity. The final instrument returned a Cronbachs alpha score of 0.921, indicating high reliability. The validity of the instrument was also established through a confirmatory factor analysis. 2023, University of Bologna. All rights reserved. -
Synergetic effects of cross-linking and incorporation of Fe-Al bimetallic combination on the properties of polyvinyl alcohol novel films
Polyvinyl alcohol films incorporated with Fe-Al bimetallic combination novel films were synthesized by sol-gel method in the presence of glutaraldehyde (GA). The results of FTIR spectra confirmed the cross-linking between PVA and GA, resulted in the formation of rigid molecular chains. The comparison of thermograms of pure PVA and Fe-Al PVA films cured with GA indicated the enhanced thermal stability of the cured films. The electrical properties of the pure PVA films and bimetallic PVA films cured with GA were studied in the frequency range 100 Hz to 100 kHz. The current study explains the effect of GA and incorporation of Fe-Al bimetallic combination towards the structural modification and dielectric properties like dielectric constant, dielectric loss, ac conductivity, polarization, and permittivity of the cured PVA films. The variation of the storage modulus of cured PVA films as a function of temperature has also been studied. 2023, Qatar University and Springer Nature Switzerland AG. -
Monoclinic yttrium oxide quantum dots surface modified by biotin for bioimaging applications
Semiconductor nanoparticles or quantum dots are one of the central topics of interest in material science research due to its size dependent physical and chemical characteristics and applications in different areas from display to biomedical fields. This work reports the first-time synthesis of biotin functionalized monoclinic yttrium oxide quantum dots at low temperature and its application in live cell imaging. The presence of biotin was confirmed through FTIR measurements. HRTEM analysis confirmed the formation of small spherical quantum dots with an average size of 3.8 nm. Zeta potential measurements gave a negative surface charge of -26.9 mV confirming colloidal stability. The quantum dots show sharp absorption in the short UV region and PL experiments delivered defect related intense blue fluorescence emission. The material is nontoxic to both normal (L929) and cancer (MCF 7) cells and the live cell imaging experiments performed on MCF 7 cells show specific binding to the cells and presented bright fluorescence emission from the cells thus confirming the applicability of the material in both display industry and cancer cell imaging. 2023 Elsevier B.V. -
Populist Protests and the Dynamic Zero-COVID Policy: (Re)emerging Pragmatic Populism in China
Populist protests in the Peoples Republic of China (PRC) have recently emerged as a reaction against the Chinese authorities stringent measures under its dynamic zero-COVID policy. Besides the vehement criticism and protests against the dynamic zero-COVID policy, during some protests, there have been ensuing calls across the country for President Xi Jinping to step down. The article argues that this scenario can further deteriorate the overall political legitimacy of the Communist Party of China on a long-term basis. According to the article, the protests indicate the re-emergence of populism in the PRC, which incidentally and historically has parallels to the protests at Tiananmen Square, and the 1919 May Fourth Movement. The article theorizes John Deweys concept of pragmatic populism and the aspect of protests during the period, which inherently provides many ideational and relational facets with the recent protests in China. 2023 Jawaharlal Nehru University. -
Designing coordinatively unsaturated metal sites in bimetallic organic frameworks for oxygen evolution reaction
Metal organic frameworks (MOFs) are developing as promising catalysts for oxygen evolution reactions. A bimetallic electrocatalyst MOF using Ni and Cu as metal sources and 1,4-benzene dicarboxylic acid as a linker has been synthesized and evaluated for oxygen evolution reaction. Compared to monometallic MOFs, bimetallic MOFs participate more actively in electrocatalysis due to the higher abundance of active sites, local crystallinity, and lower long-range disorder. When utilized as oxygen evolution catalysts, NiCu MOFs have a low overpotential of 340 mV at 10 mA/cm2 and a low Tafel slope of 65 mV/dec. The study paves the way for the development of highly efficient catalysts for water splitting applications. 2023 Elsevier Ltd -
Individual Effect of Spatially Periodic Vertical Surface Temperatures and Nanoparticles on Natural Convection in Water
This paper considers the thermo-convective boundary-layer flow (BLF) of a water-copper mono-nanofluid over a flat vertical surface which is subjected to three types of periodic temperature variations described by the sinusoidal, sawtooth, and triangular waveforms. The temperature of the fluid at the flat surface is greater than the surrounding ambient temperature. The governing equations describing the BLF have been reduced to a non-similar form using an appropriate stream function formulation. The Keller-Box method is used to obtain numerical solution of the boundary-value problem. The effect of the pertinent parameters on the nature of the flow and the heat transfer has been discussed using actual thermophysical data. The results about the shear-stress and heat transfer rate at the surface are presented as well. To study the nature of BLF, the velocity and thermal boundary-layers, the streamline and isotherm plots have been considered, which reveal that the nanoparticle volume-fraction, amplitude of surface temperature variations, and the Grashof number play a pivotal role in enhancing/diminishing heat transfer. The final outcome reveals that the heat transfer is highest for the sinusoidal waveform, followed by that of the triangular and then, the sawtooth. An important inference is that a symmetric periodic temperature distribution at the surface enhances heat transfer more than that of a constant surface-temperature. 2023 by ASME. -
MoS2-TiO2 Nanocomposites for Enhanced Photo-electrocatalytic Hydrogen Evolution
The investigation on the designing and fabrication of highly efficient electrocatalysts for hydrogen evolution reaction (HER) is critical for future applications in renewable sustainable energy. The present work reports the hydrothermal synthesis of two-dimensional MoS2 and MoS2-TiO2 nanostructures. The as-prepared nanostructures were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Raman analysis, UV-vis-NIR, and photoluminescence spectrophotometry and vibrating sample magnetometer (VSM). Systematic electrochemical measurements for HER were performed and MoS2-TiO2 nanocomposites demonstrated the lowest onset potential in comparison with MoS2. The results suggest that the nanofusion interface between MoS2 nanoflakes and TiO2 nanoparticles induced an efficient charge transfer from the conduction band of MoS2 to TiO2 and favored the reduction of H+ at active sites. We believe the present work can open up new possibilities that would provide deep insights for the rational design of 2D materials-based catalysts for energy storage and conversion applications. 2023 The Electrochemical Society (ECS). Published on behalf of ECS by IOP Publishing Limited. -
Testing for the Bidirectional Relationship Between FDI in Services and Trade in Services: Evidence from Emerging Economies
We examine the two-way links between foreign direct investments (FDI) in services and trade in services for 26 emerging economies from 2003 to 2015 using sectoral and sectoral disaggregated FDI data. Within a multivariate framework, we use panel unit root tests, recently developed heterogeneous panel cointegration and panel vector error correction model (VECM). Our results confirmed the cointegrating relationship between trade in services, FDI in services, financial services FDI and nonfinancial services FDI. We find the existence of long-run unidirectional causality from trade in services to FDI in services. However, the disaggregated analysis shows a bidirectional link between nonfinancial services FDI and trade in services in the short run. Still, there is no causality between financial services FDI and trade in services both in the short run and long run. The result also shows the evidence of unidirectional causality running from trade in services to nonfinancial services FDI in the long run. It implies that sectoral decomposition matters in the FDItrade nexus in emerging economies. JEL Codes: G20, F14, G20, F23 2022 Indian Institute of Foreign Trade.