# Bharathiar University

Recent publications
Micropolar fluid flow in a channel with variable viscosity, variable thermal conductivity and activation energy is examined numerically using the Runge–Kutta Fehlberg method in this article. Two different boundary conditions are postulated in this study namely Prescribed Surface Temperature (PST) and Newtonian Heating (NH). The numerical outcomes are compared to check the precision of the suggested problem. Significant metrics like Reynolds number, Peclet number for heat and mass transfer, Schmidt number, Activation energy and chemical reaction parameter are graphically described. The influence of the parameters like spin gradient viscosity, vortex viscosity, micro-inertia density on the flow fields are discussed and shown. According to the graphic data, the velocity increases as the viscosity parameter increases whereas the temperature decays for larger values of variable thermal conductivity and also, activation energy enhances the concentration profile. The variation in viscosity parameter shows a significant effect on thermal distribution. The viscosity variation parameter enhances the shear stress and the couple stress. The Peclet number for heat transmission displays a changing effect for high and low Biot numbers regardless of the effect of variable thermal conductivity. This analysis tabulates the link between Nusselt number and Sherwood number over a Peclet number for heat and mass transfer. The skin friction coefficient increases with the viscosity parameter ∊ whereas enhancement in the thermal conductivity parameter decreases the Nusselt number. Furthermore, sensitivity analysis is carried here by developing RSM in order to identify the variations in the input values for the parameters Peh,Pem and N1. The response surface equation is created by using the software package MINITAB-16 by design of experiments. The regression model’s quality of fit is assessed by using the Analysis of Variance.
We present the results obtained from our campaign to characterize the intra-night optical variability properties of blazars detected by the Fermi large area telescope. This involves R-band monitoring observations of a sample of 18 blazars, which includes five flat spectrum radio quasars (FSRQs) and thirteen BL Lac objects (BL Lacs) covering the redshift range z=0.085-1.184. Our observations carried out using the 1.3m J. C. Bhattacharya telescope cover a total of 40 nights (∼200 h) between the period December 2016 and March 2020. We characterized variability using the power enhanced F-test. We found duty cycle (DC) variability of about 11% for FSRQs and 12% for BL Lacs. Dividing the sample into different sub-classes based on the position of the synchrotron peak in their broadband spectral energy distribution (SED), we found DC of ∼16%, ∼10% and ∼7% for low synchrotron peaked (LSP), intermediate synchrotron peaked (ISP) and high synchrotron peaked (HSP) blazars. Such high DC of variability in LSP blazars could be understood in the context of the R-band tracing the falling part (contributed by high energy electrons) of the synchrotron component of the broadband SED. Also, the R-band tracing the rising synchrotron part (produced by low energy electrons) in the case of ISP and HSP blazars, could cause lesser variability in them. Thus, the observed high DC of variability in LSP blazars relative to ISP and HSP blazars is in accordance with the leptonic model of emission from blazar jets.
The problem of robust stabilization of interval type-2 fuzzy systems are studied by using equivalent-input-disturbance estimator-based event-triggered fuzzy control scheme. The estimator of the addressed system is designed by introducing new membership functions and then by using the same premises of the observer, the fuzzy controller is designed. To be precise, sampling-based event-triggered scheme is taken into the account in the controller design to save the communication resources and avoid the existence of Zeno behaviour. Furthermore, to compensate the impact of unknown disturbance, the equivalent-input-disturbance estimator-block is included as an internal loop of closed-loop system. To derive the stability conditions, a novel type of sampling-dependent piece-wise Lyapunov-Krasovskii functional is constructed. Then, by introducing slack matrices, the fuzzy membership function dependent stability criteria are derived. The event-triggered weighting matrix and the gains of controller and observer can be obtained by obtaining the solutions of the developed stability criteria. At last, numerical simulations are given to reflect the effectiveness and applicability of the developed theoretical results.
The Fermatean fuzzy set has been authorized as a suitable tool for the uncertainty and vagueness of information by augmenting the spatial space of acceptance membership and non-acceptance membership degrees of both intuitionistic and Pythagorean fuzzy sets. Solar energy does not emit any hazardous gases into the atmosphere, making it one of the most effective strategies to reduce global warming in the environment. Under a variety of circumstances, finding a spot for a photovoltaic solar power plant might be difficult. As a result, we experiment with multi-criteria decision-making (MCDM) techniques. We presented a hybrid technique based on the PV-SPSS method based on the Removal Effects of Criteria (MEREC) and Multiple Objective Optimization on the Basis of Ratio Analysis with Full Multiplicative Form (MULTIMOORA) analysis. The MEREC approach is used to calculate the weightage of each attribute, and MULTIMOORA is used to find the ranking of the alternatives. Also, a new rectified generalized score function determines the score value of FFSs. Culmination: the validity of the result is assessed by implementing the existing MCDM approaches and by changing the criterion weight.
The dispersion of platinum nanoparticles over B/N functionalized carbon nanofibers (CNFs) is studied using a simple electrospinning technique. The ratio of boron and nitrogen for the uniform and agglomeration-free Pt loading is optimized. Among the prepared electrocatalysts, Pt-loaded CNFs with an equal amount of B and N (Pt/HCNF-III) exhibit remarkable electrocatalytic activity towards the oxygen reduction, methanol oxidation, and hydrogen evolution reactions. Pt/HCNF-III provides a significant ECSA (62.57 m²/gm). The Pt/HCNF-III being an efficient ORR electrocatalyst follows a 4-electron pathway and renders high half-wave potential. Moreover, Pt/HCNF-III displays relatively high mass activities of 324.77 and 6.17 A g⁻¹ during MOR and HER, respectively. Pt/HCNF-III also demands a minimal overpotential (54 mV) and Tafel slope (33 mV dec⁻¹) during HER. Thus, a unique phenomenon of dopant-induced metal support interaction has enhanced the electrocatalytic activity, stability, and selectivity of the prepared electrocatalysts.
The electronic and vibrational spectral features of antiviral medication docosanol were explored by density functional theory simulations. Experimental FT-IR, FT-Raman and UV spectra were recorded and compared with the theoretically computed values. NBO analysis is utilized to figure out the stability which reveals that charge density delocalization along with hyperconjugative actions is liable for the molecule’s stability. HOMO–LUMO energy values were adopted to infer the compound’s global reactivity characteristics. To access the local reactivity parameters, the Fukui functions are calculated. The electronic structure from time-dependent density functional theory computations discloses the intramolecular charge transfer and σ → σ * electronic transitions. The most reactive sites for the nucleophilic as well as electrophilic attack were probed adopting electrostatic potential analysis. The stabilizing hydrogen bonding and hydrophobic interactions with antimicrobial and anticancer proteins were elucidated by molecular docking and the results were re-evaluated through in vitro antimicrobial and MTT assay.
In modern industrial sewing, the further rise in sewing speed to increase production is mainly influenced by the extent of needle heat generated. The increased needle heat leads to damage to the sewing thread and fabric and a loss in productivity. Hence, the change in sewing needle temperature under various fabric types and sewing conditions is investigated for better understanding. An objective method to assess the generation of needle heat by utilizing a thermal camera is attempted, and the effects of change in needle heat by varying the parameters are assessed. The results from the thermal camera are statistically analyzed. The superimposed seam with a greater number of layers and high needle tension produced high needle heat, whereas poly-poly core spun sewing thread, 100 % polyester fabric, and a high stitch density contribute to the next level of needle heat generation. This investigation considered all the possible influencing parameters objectively and helps in maintaining reduced needle heat for a chosen fabric type and sewing conditions to improve the productivity with increased sewing speed.
Cervical cancer (CC) caused by human papillomavirus (HPV) is one of the largest causes of malignancies in women worldwide. Cisplatin is one of the widely used drugs for the treatment of CC is rendered ineffective owing to drug resistance. This review highlights the cause of resistance and the mechanism of cisplatin resistance cells in CC to develop therapeutic ventures and strategies that could be utilized to overcome the aforementioned issue. These strategies would include the application of nanocarries, miRNA, CRIPSR/Cas system, and chemotherapeutics in synergy with cisplatin to not only overcome the issues of drug resistance but also enhance its anti-cancer efficiency. Moreover, we have also discussed the signaling network of cisplatin resistance cells in CC that would provide insights to develop therapeutic target sites and inhibitors. Furthermore, we have discussed the role of CC metabolism on cisplatin resistance cells and the physical and biological factors affecting the tumor microenvironments.
Neuro-oncological diseases are rare and their fatality rate is increased in patients due to advance disease development despite of the recent outcomes on neuro-oncological therapies. Artificial intelligence (AI) approaches and the exponential expansion of computing algorithms are set to increase the precision of diagnostic and therapeutic approaches in medicine. Medical imaging is one of the common AI applications where it assists radiologists in diagnosis. Radiomics has been successfully applied in neuro-oncology and it will be at forefront of AI revolution. Various AI methods can define numerous infiltrating margins of neuro-oncological diseases and it differentiates pseudo-progression from real progression and envisage recurrence and survival better than the methods used in routine practice. The present review deliberates the common neuro-oncological diseases such as glioblastoma, meningioma, spinal cord tumor and neurofibroma (NF1) and its AI algorithms related to imaging techniques such as computed (MRI) and computed tomography (CT). Also, we have discussed the beneficial aspect of AI and recent trends in diagnosis. From the study, the management of neuro-oncological diseases using AI can be revolutionized and the need of omics analysis is essential in future.
In this work, SnO2 NPs were green synthesized using Canna indica (C. indica) plant leaves extract and the synthesized powder sample was calcined at different temperatures from 400 to 700 oC. The synthesized sample was characterized using XRD, UV-vis, and FTIR spectra. Furthermore, the photocatalytic activity towards Rhodamine B (RhB) dye under visible light illumination of SnO2 nanostructures calcined at different temperatures and its cytotoxic assessment for Artemia salina (A. salina). RhB was decomposed by greater than 97% by all the samples for 30 min under sunlight irradiation while a maximum decomposition of 46% was achieved when exposed to UV lamp irradiation under similar experimental conditions and the reaction is satisfactorily described by pseudo-first-order reaction kinetics. The sample calcined at 600 oC exhibited greater toxicity for A. salina with a survival rate of 45 and 33% for 12 and 24h exposure to visible light. So, the synthesized SnO2 NPs are promising for the photodegradation of dyes and inhibiting the growth of A. salina animals in saline waters.
This paper investigates the stabilization results for a semilinear time fractional-order reaction diffusion partial differential equations using backstepping method. The parabolic system is addressed with time fractional-order of (0, 1) in the Caputo sense. More general type of actuation setup which can be expressed as Dirichlet, Neumann and Robin type boundary actuation's is considered. The main aim is to achieve the stabilization of the considered system using an invertible transformation through the stability of target system which is verified by Mittag-Leffler stability based on (Q, S, R) dissipativity theory and linear matrix inequality (LMI) technique. The explicit solutions of kernel functions are found by method of successive approximation and to be design the boundary control law for the closed loop system. Finally, the proposed results are validated through numerical examples.
A novel thiazole phenol conjugate, 2-aminothiazolesalicylaldehyde (receptor1) was designed and synthesized for the first time through a single step process via Schiff base condensation reaction. The formation of receptor1 was confirmed by FTIR, 13C NMR, and 1H NMR. The IR spectra confirmed the presence of the aldimine formation. It is further supported by the proton NMR, showing the disappearance of aldehyde peaks and the formation of a new imine peak. This is further corroborated by the 13C NMR. The receptor1 complexing with various metal ions were studied through fluorescence spectroscopy showed its selectivity toward Fe2+ ion following a reverse photoinduced electron transfer (PET) process compared to all other potentially competing ions. The receptor1 was applied as a sensor to sense Fe2+ ion in water samples. The detection limit for Fe2+ ion in drinking water was substantially lower (0.003 µM) than the EPA (environmental protection agency) recommendation (5.37 M). The capability of receptor1 in recovering Fe2+ ion in bore water, tap water, and drinking water was up to 99.5%. The receptor1 was also used as a chelating ligand (receptor1) in molecular docking and it was assessed as a potential inhibitor of NUDT5, a silence hormone signaling for breast cancer. The test compound (PDB: 5NWH) showed good affinity toward the target receptor1 with the binding energy of – 5.23 kcal mol−1. Furthermore, the receptor1 showed excellent reversibility property on adding EDTA solution. Due to the marvelous reversible property, a molecular-scale sequential information processing circuit is designed for the multi-task behavior such as ‘Writing-Reading-Erasing-Reading’ in the form of binary logic gate. The consecutive addition of Fe2+ ion and EDTA solution to receptor1 paves a way for the construction of INHIBIT logic gate. Additionally, the receptor1 showed the mimicking behavior of molecular keypad lock.
This article addresses the fault estimation and nonfragile synchronization control for multiweighted complex dynamical networks against deception attacks. An event‐triggered mechanism is proposed to reduce the redundant data transmission over the communication networks. Considering the network communication security, this article investigates deception attacks in the observer, where the adversary attempts to inject some false data in the measurement output to modify the transmitted signal in the communication networks. Some stochastic variables obeying the Bernoulli distribution are expressed to describe the probability of the deception attacks, which is determined by an attacker. Then based on Lyapunov stability theory, robust analysis method, some novel solvability criteria are presented such that the resultant augmented error system is asymptotically stable with a guaranteed H∞$${H}_{\infty }$$ performance index. Further, the existence criterion of the desired event‐triggered estimator is proposed in terms of a set of linear matrix inequalities. Finally, two illustrative examples including an F‐404 aircraft engine model are provided to verify the effectiveness of the developed estimator design method.
In the present paper, an innovative approach to enhance the photocatalytic efficiency and energy of photovoltaics by modifying the surface morphology of TiO2 is demonstrated. The photovoltaic device provides sustainable power efficiency in TiO2 (TO) and Cd-TiO2 (CTO) thin films grown through spray pyrolysis. The structural and optical properties of the prepared undoped and Cd doped TiO2 thin films were studied. The morphology and content of the pro­duced samples were studied using scanning electron microscopy (SEM with EDAX). A UV-Vis spectrophotometer was used to record the optical absorption spectra of TiO2 nanoparticles. XRD analysis showed that TO and CTO had anatase structures, and the average crystalline size was calculated as 132.0 nm. The photocatalytic efficiency of TO and CTO for degradation of Rodhamine B (RhB) dye was examined. Also, power-voltage (P-V) and photocurrent-voltage (I-V) output current intensity relations were discussed.
The Diaquabis(L-lactato)magnesium (DLLM) single crystals have been grown by slow evaporation solution growth technique. The lattice parameters and crystalline nature of the grown DLLM crystals have been studied by single and powder X-ray diffraction (XRD) analyses, respectively. The chemical composition and the corresponding functional groups of the grown DLLM have been confirmed by Fourier transform infrared (FTIR) and proton nuclear magnetic resonance (H1NMR) spectral studies. The optical transparency of DLLM in the visible region has been confirmed by ultraviolet–visible–near infrared (UV–Vis–NIR) spectrum and it has also been ensured with maximum wavelength emission from photoluminescence study. The bandgap of the DLLM material was calculated from optical absorption studies. The mechanical property of the material is studied and discussed in detail. The thermogravimetric differential thermal analysis (TG/DTA) ascertained the thermal stability of the material. The second harmonic generation (SHG) of DLLM crystal has been determined by the standard Kurtz and Perry powder method. The surface morphology of the grown DLLM crystal was observed by field emission scanning electron microscope (FESEM) analysis and the presence of the elements in the compound was confirmed with an energy-dispersive X-ray analysis (EDAX) study.
Over a couple of decades perovskite solar cells have become a highly promising photovoltaic technology. Choosing a dopant-free Hole-Transporting Material (HTM) that offers protection to a perovskite layer from oxidation is one of the viable strategies while addressing the stability of perovskite solar cell. In this line of interest, tetrathiafulvale (TTF) derivatives have shown promise in the past. However, studies that focus on small-molecule TTF derivatives as potential HTM options are scarce. The present study is an attempt to explore the applicability of a few TTF derivatives as HTM in a perovskite solar cell. Here four TTF derivatives, namely, TTF-1 (experimentally reported in a previous study), TTF-2, DBTTF1, and TMTSF1, were studied through electronic structure calculations. The properties concerning HTM, such as impact of adsorption on molecular structure, absorption spectra, distribution of frontier molecular orbitals, interaction energy between TTF derivative and MAPbI3 surface, and charge transfer at an interface, were analyzed. Results show that TTF-2 has the expected energy-level alignment, transparency in the visible range of solar spectrum, and good charge-injection ability at the interface with a perovskite layer. Hence, TTF-2 could be a potential hole-transporting material for a perovskite solar cell, and it can perform better than TTF-1.
Recent evidences illustrated that the release of aluminum oxide nanoparticles (Al2O3-NPs) into the biosphere may pose risk to the environment and cause adverse effects on living organisms including humans. The current study assessed the hepatotoxic effects of Al2O3-NPs on developing chicken embryo and cell culture models. Results demonstrated that Al2O3-NPs exposure causes histological abnormalities and increased the level of tissue damage markers (ALP, AST, and ALT) in the embryonic liver. Furthermore, increased oxidative stress (TBARS) and impaired function of antioxidant enzymes (SOD, CAT, and GPx) were also observed. Moreover, it adversely affects red blood cells (RBC) morphology, liver metabolism, and stress response gene expression (HO-1 and NQO-1). Dose-dependent ROS generation and cytotoxic response in addition to potentiating effect on tumor necrosis factor alpha (TNF-α)-induced apoptosis (caspase-3 activity) were also observed. Inhibition of p38 mitogen-activated protein kinase (p38 MAPK) and c-Jun N-terminal kinase (JNK) pathways modulates Al2O3-NPs-induced apoptosis in HepG2 cells. Novel mechanisms behind embryonic hepatotoxicity, cytotoxic potentiating effects, and possible prevention strategies have been explored.
Polyacrylonitrile (PAN)-based-modified zinc oxide (ZnO) nanofibers were synthesized by using electrospinning and hydrothermal techniques. The synthesized nanofibers were characterized by field emission scanning electron microscopy and X-ray photoelectron spectroscopy and evaluated for their ability to promote the photocatalytic degradation of the toxic herbicide atrazine. The degradation conditions were optimized by varying catalyst types, catalyst quantity, pH, light source, and toxic concentration. The degradation products were confirmed by high-performance liquid chromatography and gas chromatography–mass spectrometry (GC–MS) analyses. The extent of mineralization was calculated using total organic carbon and real-time analyses. The diameter of the La-doped ZnO-loaded PAN nanofibers was larger than that of the ZnO-seeded PAN nanofibers. The additional peak at a binding energy of 533 eV in the bonding states of La-doped ZnO/PAN indicated the presence of oxygen vacancies in the ZnO matrix, which could enhance the catalytic activity of the material. Furthermore, the degradation of atrazine depended on all the above reaction parameters. The mass spectrum of the degradation product was recorded and exhibited a molecular ion peak at m/z 187 according to GC–MS. Finally, La-doped ZnO PAN nanofibers proved to be an excellent catalyst for decontaminating atrazine within 1 h and allowed to achieve a 98% degradation efficiency.
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