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Convective instability in a horizontal porous layer saturated with a chemically reacting Maxwell fluid
The problem of onset of convective instability in a horizontal inert porous layer saturated with a Maxwell viscoelastic fluid subject to zero-order chemical reaction is investigated by linear stability analysis. Modified Darcy-Maxwell model is used to describe the fluid motion. The horizontal porous layer is cooled from the upper boundary while an isothermal boundary condition is imposed at the lower boundary. Closed form solution pertaining to the basic quiescent state is obtained. The resulting eigenvalue problem is solved approximately using the Galerkin method. The Rayleigh number, characterizing the stability of the system, is calculated as a function of viscoelastic parameter, Darcy-Prandtl number, normalized porosity, and the Frank-Kamenetskii number. The possibility of oscillatory instability is discussed. 2013 AIP Publishing LLC. -
Convective instability in a horizontal porous layer saturated with a chemically reacting viscoelastic fluid
The thesis is concerned with Rayleigh-Benard convection in a horizontal porous layer saturated with a viscoelastic fluid subject to a zero order exothermic chemical reaction. Modified Darcy law is employed to describe the fluid motion. The effect of viscoelasticity, chemical reaction, and rotation on the onset of convection is considered. The findings of the problems investigated in the thesis may prove useful in heat transfer application situations with viscoelastic fluids as working medium. -
Deciphering the properties of UV upturn galaxies in the Virgo cluster
The UV upturn refers to the increase in UV flux at wavelengths shorter than 3000 observed in quiescent early-type galaxies (ETGs), which still remains a puzzle. In this study, we aim to identify ETGs showing the UV upturn phenomenon within the Virgo galaxy cluster. We utilized a colourcolour diagram to identify all potential possible UV upturn galaxies. The spectral energy distributions (SED) of these galaxies were then analysed using the CIGALE software; we confirmed the presence of UV upturn in galaxies within the Virgo cluster. We found that the SED fitting method is the best tool to visualize and confirm the UV upturn phenomenon in ETGs. Our findings reveal that the population distributions regarding stellar mass and star formation rate properties are similar between UV upturn and red sequence galaxies. We suggest that the UV contribution originates from old stellar populations and can be modelled effectively without a burst model. Moreover, by estimating the temperature of the stellar population responsible for the UV emission, we determined it to be 13 000 K to 18 000 K. These temperature estimates support the notion that the UV upturn likely arises from the contribution of low mass evolved stellar populations (extreme horizontal branch stars). Furthermore, the Mg2 index, a metallicity indicator, in the confirmed upturn galaxies shows higher strength and follows a similar trend to previous studies. This study sheds light on the nature of UV upturn galaxies within the Virgo cluster and provides evidence that low-mass evolved stellar populations are the possible mechanisms driving the UV upturn phenomenon. 2024 The Author(s). -
Beyond the rings: Polar ring galaxy NGC 4262 and its globular cluster system
In the context of the hierarchical model of galaxy evolution, polar ring galaxies (PRGs) are considered the intermediate phase between ongoing mergers and quiescent galaxies. This study explores the globular cluster system (GCS) and its properties in the nearest PRG, NGC4262, serving as a pilot investigation to study GCS in nearby PRGs. We utilize wide and deep-field observations of the CFHT as part of the NGVS to investigate the GCS of NGC4262. We presented the first optical image of NGC4262 with an optically faint ring component. The photometric analysis of the GCS displays a distinct colour bimodality. We estimate the total number of GCs for NGC4262 to be 266 16 GCs with a specific frequency of 4.2 0.8 and a specific mass of 0.23 0.01, which is relatively high compared to other galaxies of similar mass and environmental conditions. The spatial and azimuthal distributions of subpopulations reveal strong evidence of previous interactions within the host galaxy. The colour distribution of GCS in NGC4262 shows a gradient of 0.05 0.01 within 5.5, supporting the notion of past interactions and evolutionary transitions. PRG NGC4262 conforms to the overall trend of the GCS mass with respect to the halo mass. Furthermore, our investigation of the global scaling relations between GCS and host galaxy parameters provides further support for the hypothesis that PRGs are an intermediate phase connecting ongoing mergers and quiescent galaxies. 2024 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society. -
DES J024008.08-551047.5: A new member of the polar ring galaxy family
Aims. This study presents the discovery of a new polar ring galaxy (PRG) candidate and highlights its unique features and characteristics. We provide evidence from photometric analysis that supports the inclusion of galaxy DES J024008.08-551047.5 (DJ0240) in the PRG catalogue. Methods. During the visual observations of optical imaging data obtained from the Dark Energy Camera Legacy Survey, a serendipitous discovery was made of a ringed galaxy, DJ0240. We conducted a one-dimensional isophotal analysis to determine the position angle of the ring component and its relative orientation to the host galaxy. A two-dimensional GALFIT analysis was performed to confirm the orthogonal nature of the ring galaxy and identify distinct components within the host galaxy. We compared the photometric properties of the host and ring components of DJ0240 with PRGs and other ring-type galaxies (RTGs), finding that DJ0240 shares similar properties with both of these galaxy types. Results. We have discovered the galaxy DJ0240, a PRG candidate with a ring component positioned almost perpendicular to the host galaxy. The position angles of the ring and host components are ?80 and ?10, respectively, indicating that they are nearly orthogonal to each other. The extension of the ring component is three times greater than that of the host galaxy and shows a distinct colour separation, being bluer than the host. The estimated g-r colour values of the host and ring components are 0.86 0.02 and 0.59 0.10 mag, respectively. The colour value of the ring component is similar to those of typical spiral galaxies. The host galaxy's colour and the presence of a bulge and disc components indicate that the host galaxy may be lenticular. Our findings reveal a subtle yet noticeable colour difference between the host and ring components of PRGs and RTGs. We observe that both the host and ring components of DJ0240 align more closely with PRGs than with RTGs. Furthermore, we compared the Sersic index values of the ring component (nring) of galaxy DJ0240 with a selected sample of PRGs and Hoag-type galaxies. The results show that DJ0240 has a remarkably low nring value of 0.13, supporting the galaxy's classification as a PRG. Hence, we suggest that the ring galaxy DJ0240 is a highly promising candidate for inclusion in the family of PRGs. 2024 The Authors. -
Role of biosynthesized silver nanoparticles in environmental remediation: a review
Nanoscience and nanotechnology have made remarkable advances that have significantly altered the environmental remediation process. Silver nanoparticles (AgNPs) are an essential and remarkable nanomaterial in environmental remediation. The potential of AgNPs in biomedical applications is well explored compared to their environmental applications. This review explores the biosynthesis and application of AgNPs in environmental remediation. The discussion continues with the challenges of using AgNPs for environmental remediation and concludes with the prospects of AgNPs. The review will be beneficial to all researchers and professionals who are starting their journey with AgNP synthesis. 2023, The Author(s), under exclusive licence to Springer Nature Switzerland AG. -
Long Term X-Ray Spectral Variations of the Seyfert-1 Galaxy Mrk 279
We present the results from a long term X-ray analysis of Mrk 279 during the period 2018-2020. We use data from multiple missions - AstroSat, NuSTAR and XMM-Newton, for the purpose. The X-ray spectrum can be modeled as a double Comptonization along with the presence of neutral Fe K? line emission, at all epochs. We determined the sources X-ray flux and luminosity at these different epochs. We find significant variations in the sources flux state. We also investigate the variations in the sources spectral components during the observation period. We find that the photon index and hence the spectral shape follow the variations only over longer time periods. We probe the correlations between fluxes of different bands and their photon indices, and found no significant correlations between the parameters. 2024. National Astronomical Observatories, CAS and IOP Publishing Ltd. -
Modelling the energy dependent X-ray variability of Mrk 335
We present a technique which predicts the energy dependent fractional r.m.s. for linear correlated variations of a pair of spectral parameters and apply it to an XMM-Newton observation of Mrk 335. The broadband X-ray spectrum can be interpreted as a patchy absorber partially covering the primary emission, a warm and hot coronal emission or a relativistically blurred reflection along with the primary emission. The fractional r.m.s. has a non-monotonic behaviour with energy for segments of lengths 3 and 6 ksecs. For each spectral model, we consider every pair of spectral parameters and fit the predicted r.m.s. with the observed ones, to get the pair which provides the best fit. We find that a variation in at least two parameters is required for all spectral interpretations. For both time segments, variations in the covering fraction of the absorber and the primary power law index gives the best result for the partial covering model, while a variation in the normalization and spectral index of the warm component gives the best fit in the two corona interpretation. For the reflection model, the best fit parameters are different for the two time segment lengths, and the results suggests that more than two parameters are required to explain the data. This, combined with the extreme values of emissivity index and reflection fraction parameters obtained from the spectral analysis, indicates that the blurred reflection model might not be a suitable explanation for the Mrk 335 spectrum. We discuss the results as well as the potential of the technique to be applied to other data sets of different AGN. 2025 Elsevier B.V. -
Fabrication of Didactic Model to Demonstrate Bottle Filling System Using Programmable Logic Controller
Automation is the evolution of manufacturing process which will ideally lead to e-governance. It helps humans and machines to be connected at the hip, blending the cerebral aptitudes of human and specialized abilities of automated bots to immune the workspace. Automated system has enhanced the modern day market by increasing the quality of the product as well as making the fabricating process time efficient. Lights out technology in industry promotes the robots to do work even after working hours when the lights are shut down in industry. In this research paper, a unique approach is used to fabricate a didactic model which demonstrates the working of a bottling plant which may be preferred for medium and small scale industries. To implement the process, CODESYS is used to program CPX-CEC-C1 PLC, a digital computerized system which performs logical decisions and provides outputs based on sensor inputs. The main focus is towards interfacing pneumatics and hydraulic components with PLC. 2021, Springer Nature Singapore Pte Ltd. -
Computational techniques to study the dynamics of generalized unstable nonlinear Schringer equation
In this paper, a more general form of unstable nonlinear Schringer equation which describe the time evolution of disturbances in marginally stable or unstable media is studied. A new modification of the Sardar sub-equation method is discussed and employed to retrieve solitons and other solutions of the suggested nonlinear model. A variety of solutions, including bright solitons, dark solitons, singular solitons, combo bright-singular solitons, periodic, exponential, and rational solutions are provided with considerable physical perspective. Using the q-homotopy analysis algorithm in combination with the Laplace transform, we present the approximate solutions of the bright and dark solitons, including the physical nature of the attained solutions. The computation complexity and results indicate that the given techniques are simple, effective, uncomplicated, and that they may be used to a wide range of unstable and stable nonlinear evolution equations encountered in mathematics, mathematical physics, and other applied disciplines. 2022 -
Novel approach to the analysis of fifth-order weakly nonlocal fractional Schringer equation with Caputo derivative
The main goal of this study is to find solutions for the fractional model of the fifth-order weakly nonlocal Schringer equation incorporating nonlinearity of the parabolic law and external potential using a recent modification of the homotopy analysis method (HAM) called the q-homotopy analysis transform method (q-HATM). A mixture of q-HAM and Laplace transform is the projected solutions procedure. The method contributes approximate and exact (for some special cases) solutions such as the bright soliton, dark soliton, and exponential solutions. The simulation results using Mathematica package software, demonstrate that only a few terms are enough to achieve precise, effective, and reliable approximate solutions. In addition, in terms of plots for varying fractional order, the physical behavior of q-HATM solutions has been depicted and the numerical simulation is also exhibited. The results of q-HATM reveal that the projected method is competitive, reliable, and powerful for studying complex nonlinear models of fractional type. 2021 The Authors -
Novel soliton solutions of four sets of generalized (2+1)-dimensional Boussinesq-Kadomtsev-Petviashvili-like equations
In this paper, we examined four different forms of generalized (2+1)-dimensional Boussinesq-Kadomtsev-Petviashvili (B-KP)-like equations. In this connection, an accurate computational method based on the Riccati equation called sub-equation method and its Bklund transformation is employed. Using this method, numerous exact solutions that do not exist in the literature have been obtained in the form of trigonometric, hyperbolic, and rational. These solutions are of considerable importance in applied sciences, coastal, and ocean engineering, where the B-KP-like equations modeled for some significant physical phenomenon. The graph of the bright and dark solitons is presented in order to demonstrate the influence of different physical parameters on the solutions. All of the findings prove the stability, effectiveness, and accuracy of the proposed method. 2022 World Scientific Publishing Company. -
An efficient technique for generalized conformablePochhammerChree models of longitudinal wave propagation of elastic rod
In this article, we introduce analytical-approximate solutions of time-fractional generalized Pochhammer-Chree equations for wave propagation of elastic rod by means of the q-homotopy analysis of the transform method (q-HATM). In the Caputo sense, basic concepts for fractional derivatives are defined. Several examples are given and the results are illustrated via some surface plots to present the physical representation. The results show that the current methodology is productive, powerful, efficient, easy to use, and ready to incorporate a wide variety of partial fractional differential equations. 2022, Indian Association for the Cultivation of Science. -
Numerical simulation for coupled nonlinear Schringer-Korteweg-de Vries and Maccari systems of equations
The primary goal of this paper is to seek solutions to the coupled nonlinear partial differential equations (CNPDEs) by the use of q-homotopy analysis transform method (q-HATM). The CNPDEs considered are the coupled nonlinear Schringer-Korteweg-de Vries (CNLS-KdV) and the coupled nonlinear Maccari (CNLM) systems. As a basis for explaining the interactive wave propagation of electromagnetic waves in plasma physics, Langmuir waves and dust-acoustic waves, the CNLS-KdV model has emerged as a model for defining various types of wave phenomena in mathematical physics, and so forth. The CNLM model is a nonlinear system that explains the dynamics of isolated waves, restricted in a small part of space, in several fields like nonlinear optics, hydrodynamic and plasma physics. We construct the solutions (bright soliton) of these models through q-HATM and present the numerical simulation in form of plots and tables. The solutions obtained by the suggested approach are provided in a refined converging series. The outcomes confirm that the proposed solutions procedure is highly methodological, accurate and easy to study CNPDEs. 2021 World Scientific Publishing Company. -
A novel approach to study generalized coupled cubic SchringerKorteweg-de Vries equations
The Kortewegde Vries (KdV) equation represents the propagation of long waves in dispersive media, whereas the cubic nonlinear Schringer (CNLS) equation depicts the dynamics of narrow-bandwidth wave packets consisting of short dispersive waves. A model that couples these two equations seems intriguing for simulating the interaction of long and short waves, which is important in many domains of applied sciences and engineering, and such a system has been investigated in recent decades. This work uses a modified Sardar sub-equation procedure to secure the soliton-type solutions of the generalized cubic nonlinear SchringerKorteweg-de Vries system of equations. For various selections of arbitrary parameters in these solutions, the dynamic properties of some acquired solutions are represented graphically and analyzed. In particular, the dynamics of the bright solitons, dark solitons, mixed bright-dark solitons, W-shaped solitons, M-shaped solitons, periodic waves, and other soliton-type solutions. Our results demonstrated that the proposed technique is highly efficient and effective for the aforementioned problems, as well as other nonlinear problems that may arise in the fields of mathematical physics and engineering. 2022 -
Post-road traffic injury experiences and challenges faced by college students: A qualitative study in Madurai district, Tamil Nadu, India
Road traffic injuries (RTIs) are a pressing public health concern in India, leading to a rise in injury-related deaths, hospitalizations, and disabilities. India accounts for a significant portion of the world's fatal traffic accidents, with two-wheelers being involved in the majority of these accidents. The impact of non-fatal injuries on individuals extends beyond the bodily consequences of the injury and includes both the physical and psychological dimensions of the injury. The literature indicates the need for policy cascades and implementation framework for the prevention of road traffic injury. This study aimed to investigate the post-RTI experiences and challenges faced by college students who experienced road traffic injury during their college life by using a qualitative research approach in Madurai district, Tamil Nadu, India. The study found that college students who experienced RTIs faced a wide range of physical, emotional, and social difficulties. The study highlights the need for a more comprehensive and holistic approach to RTI prevention that takes into account the complex interplay of individual, environmental, and societal factors that contribute to RTIs. The study also underscores the urgent need to improve the quality and availability of healthcare and rehabilitation services for RTI survivors. 2024 John Wiley & Sons Australia, Ltd. -
The Influence of Mobile Commerce on Consumer Behavior: A FCM-RF-DNN Analysis
For m-commerce vendors, the difficulty is to decipher what factors impact customer actions in the ubiquitous mobile setting. In addition, companies are attempting to incorporate social media into their mobile approach in some way. This proposed approach to the findings of a qualitative exploratory study regarding the use of social media and smartphones within the framework of mobile commerce. Keep in mind the order of importance while doing data preprocessing, feature selection, and training the model. The usual steps in getting data ready for processing, such as cleaning it, identifying users and sessions, and finding episodes. The IS-DT suggested method's implementation technique is utilized in feature selection. Unified FCM-RF-DNN models need to be trained after features have been retrieved. Two state-of-the-art approaches, RF and DNN, are outperformed by the suggested approach. Following the implementation of the method, accuracy improved by 96.13%. 2024 IEEE. -
A Novel Approach to Enhance Influencer Marketing in E-commerce: A Cross-A-Siamese Perspective
One of the most notable aspects of the Internet is the fact that the cost of (global) communication has been drastically decreased. Individuals may potentially reach massive audiences with their messages over the Internet due to its widespread use. With the rise of blog services, social networking platforms, etc., people's technological talents are no longer a limiting factor. Data preprocessing, feature selection, and model training should all be done in this sequence of significance. Applying fundamental data preparation techniques guaranteed the data's accuracy and relevancy. Feature selection includes the computation of an influencer's overall rank based on six important criteria, which are used for influencer identification and ranking. Feature retrieval is the first step in training Unified Cross-A-Siamese models. The proposed method outperforms two cutting-edge methods: Attention module and siamese. Accuracy increased by 95.70 percent once the approach was used. 2024 IEEE. -
Phytochemistry and Pharmacological Activities of Coriandrum sativum L.
Coriandrum sativum L. is a pharmaceutically significant herb that is used for culinary purposes and in herbal formulations. It is an annual herb from the family Apiaceae (Umbelliferae) with unique taxonomic characters. Generally called Dhania or kutumbari, it is cultivated worldwide for its distinct flavors and medicinal properties. Coriander is a rich reservoir of nutrients and significant biochemicals. The phenomenal healing properties of coriander can be attributed to the phytochemicals present in essential oils produced in various parts of the plants, such as leaves, flowers, fruit, and seed. The essential oils are rich in biochemicals like Linalool, (E)-2-decenal, 2-Decenoic acid, camphor, etc. These biomolecules altogether contribute to many pharmacological activities like analgesic, anticancer, anticonvulsant, antidiabetic, anthelmintic, antihypertensive, antimicrobial, anti-mutagenic, antioxidant, anxiolytic, diuretic, hypnotic activity. There are many scientifically proven reports to suggest its importance for usage. The present chapter summarizes the nutrition, biochemicals, and the scientifically proven pharmacological activities of Coriandrum sativum L as well as its cultivation and processing. 2022 by Nova Science Publishers, Inc.