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Rayleigh-Benard convection in a horizontal layer of porous medium saturated with a thermally radiating dielectric fluid /
IOSR Journal Of Mathematics, Vol.11, Issue 3, pp.465-474, ISSN No: 2278-5728 (Online) 2319-765X (Print). -
RayleighBard and BardMarangoni magnetoconvection in variable viscosity finitely conducting liquids
The thermorheological effect on magneto-Bard-convection is studied numerically in fluids with finite electrical conductivity. A nonlinear thermorheological equation is considered in the problem. The results are compared with the classical approach of constant viscosity, which depicts the fact that the effect of increasing the strength of the magnetic field is to delay the onset of convection. The magnetic field is shown to have a rheostatic influence on convective instabilities. The results obtained by the study have possible applications in the field of astrophysics, sunspots, and in space applications under microgravity. 2021 Wiley Periodicals LLC -
RayleighBard Convection in a Bi-viscous Bingham Fluid with Weak Vertical Harmonic Oscillations: Linear and Non-linear Analyses
Linear and weakly non-linear stability analyses of RayleighBard convection in a bi-viscous Bingham fluid layer are performed in the presence of vertical harmonic vibrations. In the linear analysis, expression is obtained for the correction Rayleigh-number arising due to the vibrations. The non-linear-analysis based on the GinzburgLandau equation is used to compute the Nusselt-number in terms of the correction Rayleigh-number. The mean-Nusselt-number is then obtained as a function of the scaled-Rayleigh-number, the frequency and the amplitude of modulation, the Prandtl number, and the bi-viscous Bingham fluid parameter. The non-autonomous amplitude-equation is numerically solved using the RungeKuttaFehlberg45 method. It is found that the influence of increasing the amplitude of modulation is to result in a delayed-onset situation and thereby to an enhanced-heat-transport situation. For small and moderate frequencies, the influence of increasing the frequency of oscillations is to decrease the critical Rayleigh-number. However, the mean-Nusselt-number decreases with increase in the frequency of oscillations only in the case of small frequencies. An increase in the value of the bi-viscous Bingham fluid parameter leads to advanced-onset and thereby to an enhanced-heat-transport situation. At very large frequencies, the effect of modulation on onset and heat-transport ceases. 2023, The Author(s), under exclusive licence to Springer Nature India Private Limited. -
RayleighBard convection in a BoussinesqStokes ferromagnetic fluid under sinusoidal and non-sinusoidal internal heat modulation
Internal heat modulation has several applications in nuclear reactor design and safety, as well as meteorology. In this paper, the influence of internal heat modulation on RayleighBard convection in a BoussinesqStokes ferromagnetic fluid is explored using linear and nonlinear analyses. The impact of the square, sine, triangular, and sawtooth wave type of internal heat modulation on the onset of convection and heat transport is considered. Using a Venezian method, linear stability analysis is performed to derive the correction Rayleigh number and the critical Rayleigh number for all four waveforms. A nonautonomous Lorenz model is derived and solved for the amplitude to obtain the Nusselt number, which quantifies the heat transport. The impact of the nondimensional parameter on the convective onset and heat transfer under heat source/sink modulation is analyzed. The study shows that all four types of internal heat modulation destabilize the system. It is also found that the presence of a heat source/sink modulation affects the impact of all four types of internal heat modulation on heat transport. 2022 Wiley Periodicals LLC. -
RayleighBard convection in a non-Newtonian dielectric fluid with MaxwellCattaneo law under the effect of internal heat generation/consumption
Purpose: The study of instability due to the effects of MaxwellCattaneo law and internal heat source/sink on Casson dielectric fluid horizontal layer is an open question. Therefore, in this paper, the impact of internal heat generation/absorption on RayleighBard convection in a non-Newtonian dielectric fluid with MaxwellCattaneo heat flux is investigated. The horizontal layer of the fluid is cooled from the upper boundary, while an isothermal boundary condition is utilized at the lower boundary. Design/methodology/approach: The Casson fluid model is utilized to characterize the non-Newtonian fluid behavior. The horizontal layer of the fluid is cooled from the upper boundary, while an isothermal boundary condition is utilized at the lower boundary. The governing equations are non-dimensionalized using appropriate dimensionless variables and the subsequent equations are solved for the critical Rayleigh number using the normal mode technique (NMT). Findings: Results are presented for two different cases namely dielectric Newtonian fluid (DNF) and dielectric non-Newtonian Casson fluid (DNCF). The effects of Cattaneo number, Casson fluid parameter, heat source/sink parameter on critical Rayleigh number and wavenumber are analyzed in detail. It is found that the value Rayleigh number for non-Newtonian fluid is higher than that of Newtonian fluid; also the heat source aspect decreases the magnitude of the Rayleigh number. Originality/value: The effect of MaxwellCattaneo heat flux and internal heat source/sink on Rayleigh-Bard convection in Casson dielectric fluid is investigated for the first time. 2020, Emerald Publishing Limited. -
RayleighBard magnetoconvection with asymmetric boundary condition and comparison of results with those of symmetric boundary condition
The paper concerns two RayleighBard magnetoconvection problems, one in a mono-nanofluid (H2OCu) and the other in a hybrid nanofluid (H2OCuAl2O3) bounded by asymmetric boundaries. A minimal FourierGalerkin expansion is used to obtain the generalized Lorenz model (GLM) which is then reduced to an analytically solvable GinzburgLandau equation using the multiscale method. The results of asymmetric boundaries are extracted by using the Chandrasekhar function with appropriate scaling of the Rayleigh number and the wave number. The solution of the steady-state version of the GLM is used to estimate the Nusselt number analytically, and the unsteady version is solved numerically to estimate the time-dependent Nusselt number and also to study regular, chaotic, and periodic convection. Streamlines are plotted and analyzed in both steady and unsteady states. The analytical expression for the HopfRayleigh number, rH , coincides with the value predicted using the bifurcation diagram. This number determines the onset of chaos. For r?> rH , one observes chaotic motion with spells of periodic motion in between. For r?< rH , one sees non-chaotic motion (regular motion). It is found that by increasing the strength of the magnetic field, we can prolong the existence of regular motion by suppressing the manifestation of chaos. The Lorenz attractor is a signature of chaos since it is found that the attractor appears only for r?> rH . The magnitude of the influence of the asymmetric boundary on rH is between those of the two symmetric boundary conditions with the freefree isothermal boundary being the one that most favors chaotic motion: A result also seen in the context of regular convection. 2023, Akadiai Kiad Budapest, Hungary. -
RCBAM-CNN: Rebuild Convolution Block Attention Module-based Convolutional Neural Network for Lung Nodule Classification
Lung cancer remains the leading cause of cancer-related deaths worldwide. Pulmonary nodules, indicative of tumor growth, present significant diagnostic challenges due to their varying sizes and shapes. Computed Tomography (CT) is commonly used for lung cancer screening due to its high sensitivity and efficacy in detecting these nodules. However, differentiating between benign and malignant nodules can be difficult due to their overlapping characteristics. To address this challenge, we propose a Rebuild Convolution Block Attention Module-based Convolutional Neural Network (RCBAM-CNN) designed to accurately classify lung nodules from CT scans. The RCBAM-CNN integrates a Rebuild Convolution Block Attention Module (RCBAM), which includes reshaped layers and redefined spatial attention mechanisms to enhance the networks focus on relevant features while minimizing noise. The performance of the proposed method is evaluated using the LIDC-IDRI dataset. Data augmentation techniques, including rotation, rescaling, and both vertical and horizontal flips, are applied to improve the models robustness and generalization. Subsequently, U-Net is employed for precise image segmentation, ensuring accurate delineation of nodule regions. The proposed RCBAM-CNN demonstrates exceptional performance, achieving an accuracy of 99.72%, surpassing existing methods such as adaptive morphology with a Gabor Filter (GF) and Capsule Network-based CNN. This approach represents a significant advancement in lung nodule classification, offering improved diagnostic accuracy and reliability. 2024 River Publishers. -
Re-evaluating Emperor Asoka a relational contract theory explanation for economic transformation
Emperor Asoka's rein is considered an important era in ancient Indian history because of the vastness of his empire and the Buddhist elements in his administration. We propose that in addition to these reasons for highlighting Asoka's rein, there is an important economic argument as well. It was during the century or two around Asoka's rule that the subcontinent's economy underwent a transformation from a simple pastoralagricultural economy to a more mature economy with large scale production, specialisation and trade. The element that Asoka introduced into the social relations in his empire is Buddha's Dhamma, which formed and strengthened relational contracts. A key feature of relational contracts is incompleteness of arrangements that is managed by social iterations and formal and informal enforcement mechanisms. Each of these is reflected in Asoka's edicts, the earliest surviving writing samples from the subcontinent. Asoka planned for these measures to ensure political and economic stability. In addition, he also laid the most important foundational material in a rather unique way for all future economic transformations. 2017 Journal of Dharma: Dharmaram Journal of Religions and Philosophies (DVK, Bangalore). -
Reaction of Indian Stock Market to Outbreak of COVID-19: An Empirical Analysis of Extreme Inter-day Movements
The contagious COVID-19 pandemic has been considered a massive global crisis since World War II and has disturbed business and economic activities across the globe. The current study examined the reaction of the stock markets to the outbreak of COVID-19, considering the extreme inter-day movements in the Indian stock market. The extreme inter-day movements in S&P CNX Nifty-50 have been identified during the study period from January 2020 to December 2021 and further classified into decline and gain events based on positive and negative announcements related to COVID-19. The study utilized an event study approach and panel regression for empirical investigation. The results of the event study analysis illustrate that the significant abnormal loss ranges from 12.86% to 2.47% for the major decline events and significant abnormal return from 8.43% to 3.23% for the gain events. The regression analysis results showed that real return and Central Bank Policy rate have a considerable impact on the abnormal returns during COVID-19. The studys findings are helpful to policy implications that identified the need to focus on financial education and strengthen the health and finance-related policies to deal with such pandemics in the future. 2023 MDI. -
Readiness factors for information technology adoption in SMEs: testing an exploratory model in an Indian context
Purpose: Extant literature regarding factors essential for successful information technologies (IT) implementation in small and medium enterprises (SMEs) does not significantly address readiness factors for IT implementation in an Indian context. This exploratory research develops and tests a framework to analyse the antecedents to organisational preparedness for adoption of IT infrastructure in SMEs. Design/methodology/approach: This exploratory research adopts a mixed-method approach to test the technology, organization and environment (TOE) framework. In-depth interviews with SME owners are conducted to develop the case study, and the measures obtained are tested through a survey at a small and medium business industrial cluster in Southern India in SMEs. Findings: The case study indicates SME owners drive to initiate technology preparedness for organisational sustainability is a key factor, a measure not seen during the literature review. An empirical study tests the measures. Pressure from customers, owners age, sales of SME, owners attitude towards IT and owners knowledge of IT was confirmed, which indicates organisational factors have more impact compared to technological and environmental factors. Research limitations/implications: The academic scope of this research paper can be extended to contexts such as readiness in IT infrastructure for digital transformation. Practical implications: The validated research framework can be used by organisation stakeholders and SME IT practitioners for successful IT adoption. Social implications: SMEs contribute significantly to gross domestic product (GDP) and provide employment opportunities. Hence, this research provides a tested model that SMEs owners/managers can adopt as a framework to augment competitiveness to implement IT. Originality/value: The study adopts a mixed-method research design and is, perhaps, a first in the Indian context to explore variables through case study and validate identified measures through an empirical study. The model can be used by SME owners and practitioners to ascertain factors for organisational preparedness for IT adoption. 2019, Emerald Publishing Limited. -
Reading Patterns, Engagement Style and Theory of Mind
Theory of mind (TOM) refers to a set of abilities which enables understanding of mental states including beliefs, emotions and intentions of self and others. The purpose of this paper is to study the effect of different reading patterns including frequency of reading fiction and genre preference on TOM performance. It also aims to compare the accuracy of TOM performance under explicit goal directed and non-directed reading conditions. To achieve this objective, a sample of 72 Indian college students were randomly allocated to two groups and were evaluated on the Reading the Mind in the Eyes Test (RMET) and the Short Story Task (SST). The two groups differed with respect to task instructions aimed at mobilizing different manner of engagement (goal directed and nondirected) with the prose in the SST. The individual reading habits and preferences of all the participants were recorded by a self report questionnaire. Scores on the novel SST showed significant positive correlation with RMET scores. No significant difference in TOM performance with respect to the different engagement styles was found, indicating that TOM abilities function continuously and equally effectively when being used in goal directed and nondirected conditions. Notably, participants who reported to prefer literary fiction performed significantly better on the SST task than the participants who prefer popular fiction. This positive link between literary fiction and TOM has important implications in clinical and developmental fields and necessitates further research. 2021, National Academy of Psychology (NAOP) India. -
Reagent-Controlled Divergent Synthesis of 2-Amino-1,3-Benzoxazines and 2-Amino-1,3-Benzothiazines
A reagent-controlled chemoselective process has been devised for the synthesis of 4H-1,3-benzoxazines and related biologically important heterocycles in high yields under mild conditions. These scaffolds could be efficiently constructed using two different chemoselective reactions that rely on the choice of reagents and reaction conditions. The treatment of various 2-amino-arylalkyl alcohols with isothiocyanates afforded thiourea intermediates, which were reacted in situ with molecular iodine in the presence of triethylamine to give 2-amino-4H-1,3-benzoxazines, whereas the corresponding 2-amino-4H-1,3-benzothiazines were obtained by the reaction of thiourea intermediates in the presence of T3P (a mild cyclodehydrating agent) and triethylamine as the base. The described protocol represents the first example for the synthesis of 4H-1,3-benzoxazines via the dehydrosulfurization method using molecular iodine as the reagent. Copyright 2019 American Chemical Society. -
Real hypersurfaces of complex space forms satisfying FischerMarsden equation
Let M be a real hypersurface of a complex space form of constant curvature c. In this paper, we study the hypersurface M which admits a nontrivial solution to FischerMarsden equation, that is, the induce metric g of M satisfies Hessg(?) = (?g?) g+ ?Sg, where ? is a nontrivial function. We prove that there does not exist a complete Hopf real hypersurface in a non-flat complex space form satisfying FischerMarsden equation. Finally, we show that a complete real hypersurface with A?= ??, ?? 0 , of a complex Euclidean space Cn satisfying FischerMarsden equation is locally congruent to a sphere or S1R2n-2. 2021, Universitdegli Studi di Ferrara. -
Real-time human action prediction using pose estimation with attention-based LSTM network
Human action prediction in a live-streaming videos is a popular task in computer vision and pattern recognition. This attempts to identify activities in an image or video performed by a human. Artificial intelligence(AI)-based technologies are now required for the security and human behaviour analysis. Intricate motion patterns are involved in these actions. For the visual representation of video frames, conventional action identification approaches mostly rely on pre-trained weights of various AI architectures. This paper proposes a deep neural network called Attention-based long short-term memory (LSTM) network for skeletal based activity prediction from a video. The proposed model has been evaluated on the BerkeleyMHAD dataset having 11 action classes. Our experimental results are compared against the performance of the LSTM and Attention-based LSTM network for 6 action classes such as Jumping, Clapping, Stand-up, Sit-down, Waving one hand (Right) and Waving two hands. Also, the proposed method has been tested in a real-time environment unaffected by the pose, camera facing, and apparel. The proposed system has attained an accuracy of 95.94% on BerkeleyMHAD dataset. Hence, the proposed method is useful in an intelligent vision computing system for automatically identifying human activity in unpremeditated behaviour. The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature 2024. -
Recent advances in electrochemical and optical sensing of the organophosphate chlorpyrifos: A review /
Critical Reviews in Toxicology, Vol.52, Issue 6, ISSN No: 1040-8444.
Chlorpyrifos (CP) is one of the most popular organophosphorus pesticides that is commonly used in agricultural and nonagricultural environments to combat pests. However, several concerns regarding contamination due to the unmitigated use of chlorpyrifos have come up over recent years. This has popularized research on various techniques for chlorpyrifos detection. Since conventional methods do not enable smooth detection, the recent trends of chlorpyrifos detection have shifted toward electrochemical and optical sensing techniques that offer higher sensitivity and selectivity. -
Recent advances in electrochemical synthesis of nitriles: A sustainable approach /
ChemistrySelect, Vol.7, Issue 12, ISSN No: 2365-6549.
Nitriles unveil widespread applications in pharmaceuticals, agrochemicals, textiles, rubber, polymers, and constitute a significant intermediate in several organic transformations, necessitating the design of simple and environmentally benign pathways for their synthesis. Over the recent years, electro-organic reactions have found widespread attention in developing effective and selective organic synthesis. They possess several advantages: high atom economy, selectivity, minimal waste production, and shorter routes to multistep traditional organic reactions. The development of novel strategies for greener and sustainable electro-organic synthesis of nitriles is therefore commendable. -
Recent developments in bandwidth improvement of dielectric resonator antennas /
International Journal of RF And Microwave Computer-Aided Engineering, Vol.29, Issue 6, pp.1-17 -
Recent developments in melamine detection: Applications of gold and silver nanostructures in colorimetric and fluorometric assays
The purity of milk, traditionally regarded as a symbol of health and nourishment, has been undermined by the alarming issue of melamine (MLM) adulteration. This nitrogen-rich compound is illicitly introduced to falsely enhance protein content, posing significant health risks. Traditional detection methods are often labor-intensive, time-consuming, or require expensive equipment. In response, researchers have developed colorimetric detection techniques to efficiently screen milk for MLM contamination. These methods are particularly promising due to their ease of preparation, rapid detection, high sensitivity, and capability for naked-eye detection. Furthermore, the unique optical properties of advanced nanomaterials have facilitated fluorometric detection, wherein the presence of contaminants induces detectable changes in fluorescence intensity or wavelength. This study offers an in-depth review of recent advancements in colorimetric and fluorometric probes based on silver (Ag) and gold (Au) nanostructures, exploring their application in food analysis. It delves into the underlying sensing mechanisms of these probes, showcasing their efficacy in detecting food contaminants. Despite the numerous advantages of Ag and Au nanostructure-based probes, challenges remain, particularly in addressing the complexity of food matrices, achieving simultaneous detection of multiple analytes, and mitigating interference from testing conditions. Additionally, this review highlights the emergence of immunoassay-based sensors, noting that many commercially available MLM testing kits utilize ELISA and LFIA platforms. For the first time, a comprehensive list of MLM testing devices and assay kits is presented, accompanied by key findings from recent studies and recommendations for future research directions. 2024 The Author(s) -
Recognition and Understanding of Emotions in Persons with Mild to Moderate Mental Retardation
Deficits in intellectual ability have been linked to deficits in emotion understanding and consequently social competence. Research suggests that individuals with mental retardation exhibit deficits in their ability to identify emotional states in themselves and others, relative to normal mental age matched controls and peers and display an inability to decode facial expressions of emotion. Emotional experience is elicited in part by a cognitive appraisal of a situation toward a goal. However, the ecological validity of previous studies is limited. In this study we developed new materials to investigate the emotion understanding skills of persons with mild to moderate mental retardation. Six tasks included faces displaying emotion in context, comic strips, audio, video and audio-visual material of individuals expressing emotions in context. Results indicated that the mentally retarded were able to identify emotions in context than expressions without context and emotion understanding improved with increasing contextual cues and dynamic content. 2014, Springer India Pvt. Ltd. -
Recommender system for personalised travel itinerary
A recommender system is an approach to give an appropriate solution to a particular problem. This helps in recognising the pattern or behaviour of a user to suggest future possible likes of the user. Nowadays people like to travel during their spare time, it has become a rigid task to decide where to go. This paper represents a customised recommender system to help users in destining their itinerary. A model is designed to suggest the best places to visit in Rome. A questionnaire was prepared to get information about user's interest during their travel. The model generates the best five places to visit with respect to the choice picked by the user. The top five places for each category will be displayed to the user and the user was asked to pick a starting point for the itinerary. Then the model generates another set off a filtered list of places to enhance their travel experience. It includes displaying the top 5 restaurants to visit during their travel. Copyright 2019 Institute of Advanced Engineering and Science. All rights reserved.