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A study on heat transfer in three-dimensional nonlinear convective boundary layer flow of nanomaterial considering the aggregation of nanoparticles
Thermal systems of solar collectors, electronic cooling, nuclear reactors, and combustion operate at high thermal conditions, and in such circumstances, the density relation of the working fluids with the thermal field may not be linear. The working fluid features are significantly affected by nonlinear density temperature fluctuations. Therefore, a theoretical study of the quadratic Boussinesq approximation (with quadratic density temperature [QDT] variation) and quadratic Rosseland radiation on the three-dimensional boundary layer dynamics and heat transport of ethylene glycol-based titania nanomaterial is carried out. The phenomenon of the kinematics of nanoparticle aggregation is also analyzed by considering modified models proposed by MaxwellBruggeman and KriegerDougherty for thermal conductivity and dynamic viscosity. The flow is induced by the elongation of a flexible flat plate in two directions. A comparison of heat transfer features of linear elongation of the plate and nonlinear elongation of the plate is conducted. The Rosseland radiative heat flux is studied in three different forms. The governing nonlinear equations are treated using apt nondimensionalization, stretching transformation, and then by using the Richardson extrapolation method. The results are presented via plots to analyze the impact of key parameters involved in the model. The magnitude of the nanomaterial temperature is enhanced due to the kinematics of nanoparticle aggregation. Among linear, quadratic, and nonlinear forms of Rosseland radiative heat flux, the quadratic radiative heat is more suitable when QDT is considered. A positive relationship is found between heat transfer and volume fraction and a positive relationship is observed between heat transfer and the QDT factor. The magnitude of the velocities and thermal field is higher for flow driven due to the linear elongation of the plate than the nonlinear case. 2021 Wiley Periodicals LLC -
Entropy generation analysis of radiative heat transfer in Williamson fluid flowing in a microchannel with nonlinear mixed convection and Joule heating
In this article, the spectral quasi-linearization (SQLM) method is implemented to solve the complicated differential equations governing the nonlinear mixed convective heat transfer of a Williamson fluid through a vertical microchannel. Unlike the conventional Boussinesq approximation, the quadratic Boussinesq approximation is taken into account in the formulation. The effects of Rosseland thermal radiation, Joule heating, and viscous dissipation are described in the thermal analysis subjected to the boundary conditions of convective thermal heating. The analysis of entropy production is also performed. The importance of various parameters governing velocity, Bejan number, temperature, and entropy generation was explored using graphic illustrations. It was found that the nonlinear density change with a temperature significantly affects the heat transport in the microchannel and thus increases the magnitude of the Bejan number and the production of entropy. Entropy production occurs maximum due to the boundary conditions of convection heating at the walls of the microchannel. Furthermore, due to a stronger viscous heating mechanism, the magnitude of the Bejan number is reduced, while the production of entropy increases significantly. As a limiting case of the problem, a comparison was made with results previously published in the literature and excellent agreement was established. The calculations provide a solid reference point for future CFD models and are relevant to the dynamics of polymers in microfluidic devices and the polymer industries. IMechE 2022. -
Effects of aggregation on TiO2ethylene glycol nanoliquid over an inclined cylinder with exponential space-based heat source: sensitivity analysis
The current study investigates the impact of nanoparticle (NP) aggregation on nanoliquid flow over an inclined elongating cylinder with an exponential space-related heat source. The dynamic viscosity and thermal conductivity for aggregation structure are modeled by utilizing the Modified Krieger-Dougherty Model and Bruggeman Model correspondingly. The governing equations are solved numerically. Further, the regression model for friction coefficient and heat transport rate is obtained by utilizing the Response Surface Methodology for various space-based heat source parameter (0.5 ? QE? 1.5), mixed convection parameter (1 ? ?? 3) and NPs volume fraction (0.01 ? ?? 0.05). The velocity profile exhibited dual features for different values of curvature parameter and NPs volume fraction. The space-based exponential heat source and mixed convection have an enhancing impact on the skin friction coefficient. It is noticed that the heat transport augments with the addition of nanoparticles. The coefficient of friction is found to be more sensitive to the NPs volume fraction. Further, the heat transport rate is more sensitive toward exponential heat source than NPs volume fraction and mixed convection. 2021, Akadiai Kiad Budapest, Hungary. -
Significance of inclined magnetic field on nano-bioconvection with nonlinear thermal radiation and exponential space based heat source: a sensitivity analysis
The characteristics of heat transport in nanoliquids under the influence of bio-convection (motile microorganism) have significant applications, since nanoliquids have greater capacity to improve heat transport properties than conventional liquids. With these incredible nanoliquid characteristics, the main objective of current research is to examine the impact of the exponential heat source linked to space and the inclined magnetic force on the nano-bioconvective flow between two turntables. The effect of nonlinear thermal radiation, variable thermal conductivity and viscosity aspects are also considered. The complicated nonlinear problem is treated numerically by using Finite difference method. Optimization procedure implemented via Response surface Methodology for the effective parameters thermophoresis parameter, Hartmann number and radiation parameter on the heat transfer rate. The axial velocity is a dwelling function of the inclined angle of the magnetic field, and the variable viscosity parameter. The temperature profile hikes with an exponential space-related heat source and thermal radiation aspects. Also, the heat transport rate is highly sensitive towards nonlinear thermal radiation parameter compared to the thermophoresis effect and Hartmann number. 2021, The Author(s), under exclusive licence to EDP Sciences, SocietItaliana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature. -
Sensitivity analysis of heat transfer in nanoliquid with inclined magnetic field, exponential space-based heat source, convective heating, and slip effects
Sensitivity analysis of the rate of heat transport in the flow of nanoliquids over an elongated sheet using the response surface methodology (RSM) in combination with the face-centered central composite design. The flow is driven due to the velocity slip and the inclined magnetic field effects. Thermal analysis includes aspects of convective heating, Joule heating, viscous heating, and a space-dependent exponential heat source. The nanoliquid model consists of thermophoresis and random motion mechanisms. A set of coupled partial differential governance equations is rehabilitated into a set of ordinary differential equations using the appropriate transformation. Subsequent nonlinear problem is tackled numerically by utilizing finite difference code that employs the formula of four-stage Lobatto IIIa. The rate of heat transport is scrutinized by adopting RSM for three effectual parameters, namely magnetic field parameter ((Formula presented.)), angle of inclination ((Formula presented.)), and suction parameter (Formula presented.)). The velocity and temperature fields were found to be a decreasing function of an angle of inclination of the magnetic field. The velocity range is inversely related to the suction and flow aspects of velocity. Furthermore, the rate of heat transport is more sensitive to the suction parameter than to the magnetic field and to the angle of inclination of the magnetic field. 2020 Wiley Periodicals LLC -
Nanoparticle aggregation effects on radiative heat transport of nanoliquid over a vertical cylinder with sensitivity analysis
A sensitivity analysis is performed to analyze the effects of the nanoparticle (NP) aggregation and thermal radiation on heat transport of the nanoliquids (titania based on ethylene glycol) over a vertical cylinder. The optimization of heat transfer rate and friction factor is performed for NP volume fraction (1% ? ? ? 3%), radiation parameter (1 ? Rt ? 3), and mixed convection parameter (1.5 ? ? ? 2.5) via the face-centered central composite design (CCD) and the response surface methodology (RSM). The modified Krieger and Dougherty model (MKDM) for dynamic viscosity and the Bruggeman model (BM) for thermal conductivity are utilized to simulate nanoliquids with the NP aggregation aspect. The complicated nonlinear problem is treated numerically. It is found that the temperature of nanoliquid is enhanced due to the aggregation of NPs. The friction factor is more sensitive to the volume fraction of NPs than the thermal radiation and the mixed convection parameter. Furthermore, the heat transport rate is more sensitive to the effect of radiative heat compared with the NP volume fraction and mixed convection parameter. 2021, Shanghai University and Springer-Verlag GmbH Germany, part of Springer Nature. -
Significance of nonlinear Boussinesq approximation and non-uniform heat source/sink on nanoliquid flow with convective heat condition: sensitivity analysis
The quadratic convective flow of nanoliquid over an elongating plate subjected to non-uniform heat source/sink, partial slip, and Newton boundary conditions is studied by using the modified Buongiorno model. The correlation for effective thermal conductivity and viscosity of nanoliquid are taken from the experimental work of Corcione. The dimensionless velocity, temperature, rate of heat transport, and mass transport distributions are simulated by solving the nonlinear boundary value problem using the finite difference method. The additional novelty of the present study is an application of response surface methodology to scrutinize the interactive impact of key parameters on the rate of heat transfer. Further, the influence of key parameters is deliberated on various flow fields using the surface and streamline plots. The higher velocities are noticed for the case of nonlinear Boussinesq approximation as compared with the usual Boussinesq approximation. The temperature enhances with a non-uniform heat source/sink aspect. The sensitivity of the heat transfer to the nanoparticle volume fraction remains positive. 2021, The Author(s), under exclusive licence to SocietItaliana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature. -
Radiative heat transfer of nanomaterial on a convectively heated circular tube with activation energy and nanoparticle aggregation kinematic effects
The improvement of the thermal conductivity of the nanoliquid due to the inclusion of a certain amount of nanoparticles is well known. However, the cause of the observed abnormal improvement remains unclear. For this reason, the aggregation kinematics of nanoparticles is significant for evaluating the appropriate thermal effect of particles at the nanoscale. The scope of nanomaterials can be seen in various engineering and industrial fields such as nuclear reactor coolants, heat exchangers, aircraft coolants, microreactor coolants, automobile radiators, solar collectors, etc. Therefore, this study investigates the effects of the aggregation of nanoparticles on radiative nanoliquid flow with activation energy over a horizontal tube subjected to the convective thermal boundary conditions. Experimentally verified correlations of multiwall carbon nanotube aggregation are utilized. The response surface methodology (RSM) is used to determine the optimum levels of the physical parameters to maximize the mass transfer rate of the nanoliquid. The magnitude of the volume fraction and velocity are superior in the absence of aggregation kinematics than in the presence of nanoparticles aggregation mechanism. From the RSM analysis, the maximum Sherwood number obtained is 1.1384 with desirability d = 0.9993. The present results may have applications in nanoliquid-dependent structures, heating/cooling processes, and thermal systems. 2021 Elsevier Ltd -
Radiated flow of chemically reacting nanoliquid with an induced magnetic field across a permeable vertical plate /
Results In Physics, Vol.7, pp.2375-2383, ISSN: 2211-3797. -
Marangoni convective MHD flow of SWCNT and MWCNT nanoliquids due to a disk with solar radiation and irregular heat source /
Physica E : Low-Dimensional Systems And Nanostructures, Vol.94, pp.25-30, ISSN: 1386-9477. -
Nonlinear convective and radiated flow of tangent hyperbolic liquid due to stretched surface with convective condition /
Results In Physics, Vol.7, pp.2404-2410, ISSN: 2211-3797. -
Effects of chemical reaction and partial slip on the three-dimensional flow of a nanofluid impinging on an exponentially stretching surface /
The European Physical Journal Plus, Vol.132, Issue 113, pp.1-18, ISSN: 2190-5444. -
Redefining copreneurs: a four decadal review adopting computer aided text analysis
The study defines copreneurs and presents a four decadal review on copreneurial literature. The purpose is to bring conceptualization and characterization of copreneurs, on surface from its fragmented literature. A structured literature review on copreneurship research published between 1984 and 2023 is conducted. The search is made adopting indexing (Scopus, Clarivate and ABDC), digital libraries including ProQuest and EBSCO, and research articles published in journals by renowned publishers namely Elsevier, Emerald, Inderscience, Sage, Springer, Taylor & Francis and Wiley. Inclusion/exclusion criteria was defined and duplicates were eliminated. Finally, using POWER review model, the existing literature is organized under six themes namely Gender Roles, Spousal Support & Relationship Satisfaction, Work Life Balance, Business Commitment & Motivation, Leadership & Decision Making and Division of Labour & Responsibilities in the Intertwined Worlds. Using Inter- Rater Reliability, five definitions of copreneurs were framed and rated by nine experts from academics and industry. Finally, the definition with highest score and acceptable I-CVI value for simplicity & clarity is proposed. The fragmented literature on copreneurs speaks volume about the need for more impactful research on them. By using the proposed definition of copreneurs, scholars can uniformly identify the copreneurs, with future opportunities for micro-level research on copreneurs. Policy makers can utilise the findings of these research and formulate schemes, policies & programmes for betterment of copreneurs. The study intends to bridge the disciplinary gaps existing for identifying copreneurs and serve as a foundation for information sharing, regarding copreneurs and their entrepreneurial practices. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024. -
Theoretical and analytical analysis of convective heat transport of radiated micropolar fluid over a vertical plate under nonlinear Boussinesq approximation
Purpose: In heat transfer problems, if the temperature difference is not sufficiently so small then the linear Boussinesq approximation is not adequate to describe thermal analysis. Also, nonlinear density variation with respect to temperature/concentration has a significant impact on heat and fluid flow characteristics. Because of this reason, the impact of nonlinear density variation in the buoyancy force term cannot be neglected. Therefore in this paper, the unsteady flow and heat transfer of radiating magneto-micropolar fluid by considering nonlinear Boussinesq approximation is investigated analytically. Design/methodology/approach: The flow is fully developed and time-dependent. Heat and mass flux boundary conditions are also accounted in the analysis. The governing equations of transport phenomena are treated analytically using regular perturbation method. To analyze the tendency of the obtained solutions, a parametric study is performed. Findings: It is established that the velocity field is directly proportional to the nonlinear convection parameter and the same trend is observed with the increase of the value of Grashof number. The micro-rotational velocity profile decreases with increase in the nonlinear convection parameter. Further, the temperature profile increases due to the presence of radiative heat aspect. Originality/value: The effectiveness of nonlinear Boussinesq approximation in the flow of micropolar fluid past a vertical plate in the presence of thermal radiation and magnetic dipole is investigated for the first time. 2019, Emerald Publishing Limited. -
LBP-GLZM Based Hybrid Model for Classification of Breast Cancer
Classifying mammogram images is difficult because of their complex backgrounds and the differences in resolutions across the images. One of the toughest parts is telling the difference between harmless (benign) and harmful (malignant) tissue. This is hard because the differences between them are incredibly subtle. As a consequence, the distinctive features embedded within tissue patches become not just relevant but critical for the accurate and automatic classification of these images. Traditionally, efforts to automate this classification process have encountered limitations when relying on a singular feature or a restricted set of characteristics. The subtle variations in texture within these images often render such approaches insufficient in achieving high-quality categorization results. Recognizing this, the present investigation undertakes a more comprehensive approach by incorporating distinct feature extraction techniques - specifically, the utilization of Local Binary Pattern (LBP) and Gray Level Zone Matrix (GLZM). These techniques are adept at capturing and delineating the nuanced texture features inherent in mammogram images. By extracting and analyzing these textural nuances, the aim is to construct a hybrid model capable of classifying mammograms into three distinct categories: malignant, benign, and without the necessity for further examination or follow-up. This proposed hybrid model holds significant promise in the field of mammography classification by leveraging the strengths and complementary attributes of multiple feature extraction methods. The integration of LBP and GLZM aims not only to enhance the accuracy of classification but also to improve the robustness of the system in identifying subtle yet crucial differences in tissue textures. Ultimately, the goal is to create a hybrid feature extraction framework that augments the diagnostic capabilities of mammography, providing more precise and reliable categorization of breast tissue for effective medical decision-making and patient care. 2024 IEEE. -
Energy harvesting using two-dimensional magnesiochromite (MgCr2O4)
Two-dimensional (2D) materials with high surface activity can be utilized for harvesting energy from small mechanical sources using flexoelectricity. In the present work, we have synthesized an atomically thin 2D spinel MgCr2O4 by a liquid-phase exfoliation process, and characterization shows the preferential exfoliation along the (111) plane with low formation energy. The fabricated flexoelectric device produces an electrical response up to ?3 V (peak-to-peak voltage) upon pressing and releasing the cell with ?0.98 N force. Furthermore, the energy harvesting properties of 2D MgCr2O4 are explored by combining bending with other sources of external energy, with applied varying magnetic flux (Vmax = ?2.6 V) and temperature with 0.9 N force (Vmax = ?18 V). Our calculations determine that 2D MgCr2O4 has a flexoelectric coefficient of approximately ?XZXZ = 0.005 nC/m. Overall, the results indicate that 2D MgCr2O4 is a very promising material for the next generation of self-powered wearable electronics and energy harvesting. 2023 Elsevier Ltd -
Deep vs. Shallow: A Comparative Study of Machine Learning and Deep Learning Approaches for Fake Health News Detection
Internet explosion and penetration have amplified the fake news problem that existed even before Internet penetration. This becomes more of a concern, if the news is health-related. To address this issue, this research proposes Content Based Models (CBM) and Feature Based Models (FBM). The difference between the two models lies in the input provided. The CBM only takes news content as the input, whereas the FBM along with the content also takes two readability features as the input. Under each category, the performance of five traditional machine learning techniques: - Decision Tree, Random Forest, Support Vector Machine, AdaBoost-Decision Tree and AdaBoost-Random Forest is compared with two hybrid Deep Learning approaches, namely CNN-LSTM and CNN-BiLSTM. The Fake News Healthcare dataset comprising 9581 articles was utilized for the study. Easy Data Augmentation technique is used to balance this highly imbalanced dataset. The experimental results demonstrate that Feature Based Models perform better than Content Based Models. Among the proposed FBM, the Hybrid CNN - LSTM model had a F1 score of 97.09% and AdaBoost-Random Forest had a F1 Score of 98.9%. Thus, Adaboost-Random Forest under FBM is the best-performing model for the classification of fake news. 2013 IEEE. -
Effect of Organizational Culture during Crises on adoption of virtual classrooms: An extension of UTAUT model
This study aims to understand the impact of organizational culture in the context of obligatory adoption of a virtual classroom (VC) during the COVID pandemic. The academic crisis created by the pandemic resulted in obligatory adoption of VCs, without being mandated by top management. Organizational culture was tested by this crisis, and thus created a unique opportunity to examine adoption. This research examines Organizational Culture during Crises (OCC) as an antecedent to the Unified Theory of Acceptance and Use of Technology (UTAUT) model to evaluate the factors that determine the intention to adopt a virtual classroom across multiple disciplines by the faculty of a reputed Indian university. Data collected from a sample of 353 respondents was analyzed to test the research model using Structural Equation Modeling (SEM). The findings of the study reveal that OCC plays a positive and significant role in determining the intention of faculties to adopt a virtual classroom. We also found that OCC also significantly influences performance expectancy, effort expectancy, facilitating conditions and social influence. The results imply proper framing of policies by top management of Higher Education Institutions (HEI) for the smooth adoption of virtual classrooms by faculty when confronted by crises. 2021 The Author(s). Published with license by Taylor & Francis Group, LLC. -
Search and analysis of giant radio galaxies with associated nuclei (SAGAN): III. New insights into giant radio quasars
Giant radio quasars (GRQs) are radio-loud active galactic nuclei (AGN) that propel megaparsec-scale jets. In order to understand GRQs and their properties, we have compiled all known GRQs (the GRQ catalogue) and a subset of small (size < 700 kpc) radio quasars (SRQs) from the literature. In the process, we have found ten new Fanaroff-Riley type-II GRQs in the redshift range of 0.66 < z < 1.72, which we include in the GRQ catalogue. Using the above samples, we have carried out a systematic comparative study of GRQs and SRQs using optical and radio data. Our results show that the GRQs and SRQs statistically have similar spectral index and black hole mass distributions. However, SRQs have a higher radio core power, core dominance factor, total radio power, jet kinetic power, and Eddington ratio compared to GRQs. On the other hand, when compared to giant radio galaxies (GRGs), GRQs have a higher black hole mass and Eddington ratio. The high core dominance factor of SRQs is an indicator of them lying closer to the line of sight than GRQs. We also find a correlation between the accretion disc luminosity and the radio core and jet power of GRQs, which provides evidence for disc-jet coupling. Lastly, we find the distributions of Eddington ratios of GRGs and GRQs to be bi-modal, similar to that found in small radio galaxies (SRGs) and SRQs, which indicates that size is not strongly dependent on the accretion state. Using all of this, we provide a basic model for the growth of SRQs to GRQs. ESO 2022. -
Wearable Smart Technologies: Changing the Future of Healthcare
Wearable smart technologies are the innovative solutions for the issues of healthcare services. In this chapter, a review of the innovative wearable healthcare devices and applications has been done. Wearable devices are used for supervision and illness control. These innovative wearable technologies can straightforwardly affect the medical dynamic, can upgrade the quality of treatment for patients, and can reduce the expenses incurred in it. The large health record generated by the wearable devices provides an opportunity for data analysts to apply machine learning techniques for prediction on the data generated by sensors. Today's wearable smart technologies are capable of being integrated into eyeglasses, cloths, shoes, belts, watches, etc. Sensors can be inserted in these objects to be worn. The advanced forms of wearable technologies can be attached to the skin of the wearer. A smartphone is mainly utilized to collect data and communicate it to a server situated at a remote area for greater capacity and investigation. Maximum innovations related to wearable technologies are still in the prototyping phase. The study covers almost every aspect of wearable technologies, which could be helpful in the future for innovation and research in this area. 2024 selection and editorial matter, Ankur Beohar, Ribu Mathew, Abhishek Kumar Upadhyay, and Santosh Kumar Vishvakarma -individual chapters, the contributors. All rights reserved.