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Experimental and Theoretical Investigation of 3-[(2-chlorophenyl)diazenyl]pyridine-2,6-diamine as Optical Limiter
Azobenzenes undergo reversible trans-cis photoisomerization and have been extensively studied as photoresponsive material. In contrast, azopyridines have garnered relatively less attention despite their similar photochemistry. When compared to azobenzene, azopyridines offer more opportunities for material design through hydrogen bonding and coordination chemistry. Here, we report the isomerization for 3-[(2-chlorophenyl)diazenyl]pyridine-2,6-diamine (1od) through an integrative experimental and computational study. Notably, the energy barrier of 1od was significantly lower than that of previously reported azobenzenes. Moreover, we investigated and elucidated the photoisomerization pathway. 1od exhibited high nonlinear absorption, with a nonlinear absorption coefficient (?eff) of 1.31 (Formula presented.) 10?9 m W?1, as determined by Z-scan measurements. The results indicate that 1od has potential applications in optical limiters, which are used to fabricate protective eyewear and safeguard optical sensors from damage. 2023 Wiley-VCH GmbH. -
Spectroscopic and TDDFT investigation of highly selective fluoride sensors by substituted acyl hydrazones
In this work, we report the synthesis of two receptors for fluoride ions based on acyl hydrazone, such as N?-[(1Z)-1-(4-fluorophenyl)ethylidene]benzohydrazide (R1) and N?-[(1Z)-1-(2-hydroxyphenyl)ethylidene]benzohydrazide (R2). The receptors R1 and R2 were synthesized from the corresponding ketones and benzoic acid hydrazide and characterized spectroscopically by UVvisible, IR and 1HNMR techniques. The response of R1 and R2 towards different anions was studied colourimetrically in acetonitrile. The receptors exhibited a specific response towards fluoride ions. Further studies of 1:1 composition of receptors, R1/R2:fluoride ions by different spectroscopic techniques such as UVVisible, IR and 1HNMR spectroscopy indicated the participation of -NH proton of the receptors in the sensing action through the hydrogen bonding. To understand the mechanism, Time-Dependent Density Functional Theory (TD-DFT) studies were done using the CAM-B3LYP/6311G++ (3df,2p) with Grimme's D3BJ empirical dispersion basis set. The studies supported the role of hydrogen bonding interaction of -NH and-OH protons of the receptors with the fluoride ions. 2020 Elsevier B.V. -
Unveiling the therapeutic potential of azopyridine derivatives for trypsin inhibition: a DFT and In-Vitro approach
Heterocyclic azo derivatives have emerged as promising scaffolds for drug development. This study focused on the synthesis, computational analysis, and biological evaluation of a series of azopyridine derivatives (1a, 1d, 1 g, 1 h, 1 m, 1p, and 1s) as potential trypsin inhibitors. Density Functional Theory calculations indicated that derivative 1 h exhibited the lowest HOMO-LUMO energy gap 3.167 eV and was characterised as a soft molecule, suggesting strong binding capabilities. Molecular docking studies confirmed that 1 h binds favourably to the active site of trypsin with a glide score of ?6.581 kcal/mol and binding energy of ?29.95 kcal/mol. Along with docking studies, the stability of the trypsin-1 h complex was further analyzed using molecular dynamic simulations at 200 ns. The results showed that the ligand molecule 1 h bound strongly at the active site of trypsin. In-vitro enzyme assays determined the IC50 value of the molecule as 100 M, demonstrating enhanced potency. These results indicate that AzPy derivatives, particularly 1 h, hold considerable promise as therapeutic agents for inflammatory disorders and cancer, paving the way for further exploration in drug development and targeted therapies. Further research is warranted to explore 1hs efficacy, safety, and structure-activity relationships. Highlights: DFT studies were used to classify molecules based on their softness and hardness. Molecular docking, simulation, and in-vitro studies have identified potential anti-trypsin activity of candidate molecules. Experimental and computational calculations were in close agreement. 2024 Informa UK Limited, trading as Taylor & Francis Group. -
Diazo-pyrazole analogues as photosensitizers in dye sensitised solar cells: Tuning for a better photovoltaic efficiency using a new modelling strategy using experimental and computational data
The designing of a dye sensitised solar cell (DSSC) is one of the frontiers in harvesting solar energy as it provides an alternative to economic photovoltaic devices with increased efficiency. In this manuscript, we report a new methodology using experimental and theoretical data for the evaluation of the photosensitiser activity of organic dyes using theoretical simulations and experimental cell efficiency data. As a representative example, we designed a series of 54 novel pyrazole derivatives which are subjected to TD-DFT simulations (CAM-B3LYP/6-311G++ (2d, p)) and photovoltaic modelling. Data from computational simulations, as well as known experimental cells, are used for the calculation of photovoltaic efficiency. We selected pyrazole derivatives because of its proven use in DSSC as an effective dopant in a blended polymer electrolyte in nanocrystalline DSSC. Fine-tuning with the effect of substitution and with the ?spacers at the ortho, meta and para positions for -OCH3, -OH, -CHO, -NO2 respectively were done. Enhanced efficiency of 7.439% was observed as compared to the standard cell of efficiency of 5.530%. An increase in efficiency was not observed with the effect of ?spacers. The newly designed dyes demonstrate desirable energetic and spectroscopic parameter that can lead to efficient metal-free organic dye sensitiser for DSSC's. The main advantage of this strategy is the incorporation of both simulated and experimental data. It will reduce the possible errors from the simulations and also, helps in performing time-consuming experimental studies. 2020 Walter de Gruyter GmbH, Berlin/Boston. -
Photoisomerization Dynamics of 2-[(E)-(4-fluorophenyl)diazenyl]-1 H -imidazole: A Theoretical and Experimental Insight
This study investigates the photoresponsive behavior of substituted azobenzenes with a specific focus on their nonlinear optical response. This study suggests that azoimidazole substitution is a better alternative to azobenzene derivatives for nonlinear optical responses. The synthesis, characterization, photophysical property and isomerization pathway of 2-[(E)-(4-fluorophenyl)diazenyl]-1H-imidazole (E-2g) are presented as an optical limiter through a comprehensive blend of experimental and theoretical approaches. Notably, E-2g exhibited a lower energy barrier than reported azobenzenes. The trans-to-cis photostationary state was reached in 75 min, while the cis-to-trans state was achieved in 60 min at 354 nm. The study further explores the photoisomerization pathway of E-2g, highlighting its nonlinear absorption, which has a nonlinear absorption coefficient (?eff) of 8.8 10-11 m/W at 20 ?J, as determined by Z-scan measurements. The results suggest that E-2g exhibits significant nonlinear absorption characteristics, which helps in applications requiring protection from intense light sources. 2024 World Scientific Publishing Company. -
Detection of strangers based on dogs sound
Nowadays, people having a pet at home are increasing. Usually, dog is the favorite pet animal for most of the people in the world. Dogs are more capable of identifying strangers in the surroundings than humans. The proposed work identifies the strangers based on the barking sound of the dog. In this anticipated work, multiple features are extracted from the dogs barking sound using Fast Fourier Transform and Statistical based methods. The classification is done using Nae Bayes classifier. The dataset contains 770 barking audio files of 8 dogs. Whenever known and unknown person comes home, the sounds of the dogs are recorded. The classification result for identifying the stranger is 79.1094%. BEIESP. -
Study of nanofluid flow in a stationary cone-disk system with temperature-dependent viscosity and thermal conductivity
The substantial temperature gradient experienced by systems operating at relatively high temperatures significantly impacts the transport characteristics of fluids. Hence, considering temperature-dependent fluid properties is critical for obtaining realistic prediction of fluid behavior and optimizing system performance. The current study focuses on the flow of nanofluids in a stationary cone-disk system (SCDS), taking into account temperature-dependent thermal conductivity and viscosity. The influence of Brownian motion, thermophoresis, and Rosseland radiative flux on the heat transport features are also examined. The Reynolds model for viscosity and Chiam's model for thermal conductivity are employed. The Navier-Stokes equation, the energy equation, the incompressibility condition, and the continuity equation for nanoparticles constitute the governing system. The Lie-group transformations lead the self-similar ordinary differential equations, which are then solved numerically. Multi-variate non-linear regression models for the rate of heat and mass transfers on the disk surface were developed. Our study reveals a notable decrease in the rate of heat and mass transfer when pre-swirl exists in the flow. The significant influence of nanofluid slip mechanisms on the effective temperature and nanofluid volume fraction (NVF) within the system is highlighted. Furthermore, the variable viscosity property enhances the temperature and NVF of the SCDS. 2024 Author(s). -
Study of hybrid nanofluid flow in a stationary cone-disk system with temperature-dependent fluid properties
Cone-disk systems find frequent use such as conical diffusers, medical devices, various rheometric, and viscosimetry applications. In this study, we investigate the three-dimensional flow of a water-based Ag-MgO hybrid nanofluid in a static cone-disk system while considering temperature-dependent fluid properties. How the variable fluid properties affect the dynamics and heat transfer features is studied by Reynoldss linearized model for variable viscosity and Chiams model for variable thermal conductivity. The single-phase nanofluid model is utilized to describe convective heat transfer in hybrid nanofluids, incorporating the experimental data. This model is developed as a coupled system of convective-diffusion equations, encompassing the conservation of momentum and the conservation of thermal energy, in conjunction with an incompressibility condition. A self-similar model is developed by the Lie-group scaling transformations, and the subsequent self-similar equations are then solved numerically. The influence of variable fluid parameters on both swirling and non-swirling flow cases is analyzed. Additionally, the Nusselt number for the disk surface is calculated. It is found that an increase in the temperature-dependent viscosity parameter enhances heat transfer characteristics in the static cone-disk system, while the thermal conductivity parameter has the opposite effect. The Author(s) 2024. -
Study of nanofluid flow and heat transfer in a stationary cone-disk system
Rheometric, viscosimetric, bio-medical, and several other pharmaceutical machineries utilize the structural advantages provided by the geometry of a stationary conical diffuser. The problem of the Buongiorno nanofluid flow in the conical gap of a stationary cone-disk system for isothermal boundaries is studied. The governing system, comprising the incompressibility condition, NavierStokes equation, energy conservation equation, and conservation of Nanoparticle Volume Fraction (NVF) equation, is analyzed. The Lie-group theory has been used to derive a self-similar model. Solutions of the self-similar equations were computed numerically, and the expressions for the Nusselt number and Sherwood number are obtained. The parametric investigation reveals that the heat and mass transfer rate subside significantly when pre-swirl is introduced to the flow. Furthermore, the nanofluid slip mechanisms enhance the effective temperature of the system. 2023 Elsevier Ltd -
Architecture of FTO/n-CdS/p-SnSe1-xOx/Au Heterojunction Thin Film Diodes by Thermal Evaporation
In this report, FTO/n-CdS/p-SnSe1-xOx/Au heterojunction diodes were fabricated using a homemade precursor followed by dry milling with a facile thermal evaporation method under oxygen atmosphere (10? 2mbar) for the first time. The chemical purity (45.35:45.07:9.58 at.%) and microstructure of the deposited films and device were characterized by energy dispersive x-ray analysis, x-ray photoelectron spectroscopy, and scanning electron microscopy. The crystallographic parameters, a = 11.512 b = 4.163and c = 4.452 with orthorhombic crystal structure and monophase nature were analyzed by powder x-ray diffraction. Raman spectroscopy revealed the vibrational modes, and UVVis-NIR spectroscopy was used to study the direct nature of optical absorption with a band gap of 1.14eV. The currentvoltage (I-V) characteristics of the semiconductor diode were measured in room temperature (25C) and revealed rectifying properties and the cut-off voltage for the device, 0.57V. The obtained results highlight that the use of a p-SnSe1-xOx (SSO) layer as an interface between n-CdS/Au diodes exhibits excellent rectifying behavior and enhanced diode performance. Therefore, the p-SSO layer is a suitable material for heterojuction diodes and optoelectronic switches. Graphical Abstract: [Figure not available: see fulltext.]. 2022, The Minerals, Metals & Materials Society. -
Adsorptive removal of Cr (VI) using mesoporous iron-aluminum oxyhydroxide-polyvinyl alcohol self-supporting film: Kinetics, optimization studies and mechanism
Over the past decades, the disposal of heavy metals like Cr(VI) from industries had an adverse effect on the environment, thus making it a topic of particular interest. In this context, mesoporous Aluminum oxyhydroxide-polyvinyl alcohol self-supporting films were synthesized, and different transition metals (V, Fe, Co, Ni and Cu) were incorporated by an eco-friendly route, and their adsorptive capacity towards Cr (VI) was studied. The composite mesoporous film with iron, aluminum oxyhydroxide and PVA was more efficient adsorbent than other transition metal incorporated aluminum oxyhydroxide films. The surface and chemical properties of the film were confirmed by pXRD, FTIR, Raman Spectra, BET-Surface area, BJH, SEM and Optical Profilometry. Furthermore, the effect of different parameters that impact the adsorption capacity towards Cr (VI) is discussed, including adsorbent load, contact time, solution pH, temperature, and initial concentration. A detailed investigation of the film before and after the adsorption of Cr (VI) using different characterization techniques is investigated in detail. The kinetic studies and adsorption isotherms are studied, and a suitable mechanism has been proposed for Cr (VI) removal. The synthesized films possess potential advantages like cost-effectiveness, eco-friendly nature, reusability, and higher removal efficiency towards the removal of Cr (VI) from an aqueous solution. 2023 Elsevier Ltd -
Further Results on the 3-Consecutive Vertex Coloring Number of Certain Graphs
A 3-consecutive vertex coloring is an assignment of colors on vertices of a graph G such that for any 3-consecutive vertices a, b and c, the color of b is the same as the color of a or c. ? 3c(G) denotes the maximum number of colors that can be used to 3-consecutive vertex color a graph G. The main aim of this article is to give the value of ? 3c(G) for some particular types of graphs, which includes: necklace graphs; the Cartesian product of two paths, a cycle and a path, and two cycles; the corona product of a path and a clique; Mobius Ladder graphs; the 3rd edge line graph; triangular snake graphs, double triangular snake graphs, triple triangular snake graphs, quadrilateral snake graphs and the alternative versions of them; Hanoi graphs; Sun graphs; Barbel graphs; the n-pan graph. The objective of this article is to explore some important results on ? 3c(G). 2024 The Authors. -
PICTURE PROCESSING ON ISOMETRIC FUZZY REGULAR ARRAY LANGUAGES
Isometric array grammar is one of the simplest model to generate picture languages, since both sides of its production rule have the same shape. In this paper, we have introduced isometric fuzzy regular array grammars to generate isometric fuzzy regular array languages and discussed its closure properties. Also, the relation between isometric fuzzy regular array grammar and boustrophedon fuzzy finite automata has been discussed. Moreover, we study the relation between two dimensional fuzzy regular grammars with returning fuzzy finite automata and boustrophedon fuzzy finite automata. Further, the hierarchy results of these three classes of languages have been discussed. 2024 KSCAM. -
Two dimensional fuzzy context-free languages and tiling patterns
Fuzzy context-free languages are powerful compared to fuzzy regular languages as they are generated by fuzzy context-free grammars and fuzzy pushdown automata, which follow an enhanced computational mechanism. A two dimensional language (picture language) is a collection of two dimensional words, which are a rectangular array of symbols made up of finite alphabets. Two dimensional automata can recognize two dimensional languages that could not be recognized by one dimensional automata. In this paper, we introduce two dimensional fuzzy context-free languages generated by the two dimensional fuzzy context-free grammars and accepted by the two dimensional fuzzy pushdown automata in order to deal with the vagueness that arises in two dimensional context-free languages. We can construct a two dimensional fuzzy context free grammar from the given two dimensional fuzzy pushdown automata and vice versa. In addition, we prove that two dimensional fuzzy context-free languages are closed under union, column concatenation, column star, homomorphism, inverse homomorphism, reflection about right-most vertical, reflection about base, conjugation and half-turn and also show that two dimensional fuzzy context-free languages are not closed under matrix homomorphism, quarter-turn and transpose. Further, we have given the applications and the uses of closure properties in the formation of tiling patterns. 2024 Elsevier B.V. -
Informal Waste Recycling in Dharavi A Marxist Feminist Reading of The Women of Wasteland
[No abstract available] -
An adaptive inertia weight teachinglearning-based optimization for optimal energy balance in microgrid considering islanded conditions
The energy balance in islanded microgrids is a complex task due to various operational constraints. This paper proposes a new approach to multi-objective optimization for achieving energy balance in aMicrogrid(MG) in both islanded and normal modes. Optimal load control (OLC)is achallenge, due to a lack of capacity to generate the global optimum after each run. The latest variant of Teaching Learning Based Optimization (TLBO), known as Adaptive-TLBO, includes both modifications during exploitation and exploration stages (ATLBO). The results achievedwith the proposed method are exceptional on a modified IEEE 33-bus system. In addition to the improvement of the voltage profile and the decrease of the distribution losses, the energy balance improves with the method. The proposed ATLBO algorithm overrides any proposed other algorithm, as shown by comparison with PSO, base TLBO, Backtrackingsearch algorithm (BSA) and cuckoo search algorithms, etc. (CSA). The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2022. -
Optimal Load Control for Economic Energy Equilibrium in Smart Grid Using Adaptive Inertia Weight Teaching-Learning-Based Optimization
Due to numerous operational restrictions and economic purposes, optimal load management for energy balance in the smart grid (SG) is one of the compensating responsibilities. This research provides a novel multiobjective optimization technique for attaining energy balance in SG, with the goal of avoiding fines due to excessive upstream network power extraction beyond contractual demand. Due to a lack of capacity to create the whole optimization towards the global optimum after each run, optimal load control (OLC) is a prevalent challenge. Adaptive-TLBO, the most recent variation of Teaching Learning Based Optimization (TLBO), comprises both alterations during the exploitation and exploration phases (ATLBO). Because the ATLBO is used on a modified IEEE 33-bus system, the results obtained in this mode are extraordinary. The energy balance has improved in addition to the enhancement of the voltage profile and the reduction of distribution losses. As evidenced by comparisons with PSO, basic TLBO, backtracking search algorithm (BSA), and cuckoo search algorithms, the suggested ATLBO algorithm has precedence over any other proposed algorithm (CSA) 2022, International Journal of Intelligent Engineering and Systems.All Rights Reserved. -
Modelling of Cointegration with Students T-errors
Two or more non-stationary time series are said to be co-integrated if a certain linear combination of them be-comes stationary. Identification of co-integrating relationships among the relevant time series helps the researchers to develop efficient forecasting methods. The classical approach of analyzing such series is to express the co-integrating time series in the form of error correction models with Gaussian errors. However, the modeling and analysis of cointegration in the presence of non-normal errors needs to be developed as most of the real time series in the field of finance and economics deviates from the assumption of normality. This paper focuses on modeling of a bivariate cointegration with a students-t distributed error. The co-integrating vector obtained from the error correction equation is estimated using the method of maximum likelihood. A unit root test of first order non stationary process with students t-errors is also defined. The resulting estimators are used to construct test procedures for testing the unit root and cointegration associated with two time series. The likelihood equations are all solved using numerical approaches because the estimating equations do not have an explicit solution. A simulation study is carried out to illustrate the finite sample properties of the model. The simulation experiments show that the estimates perform reasonably well. The applicability of the model is illustrated by analyzing the data on time series of Bombay stock exchange indices and crude oil prices and found that the proposed model is a good fit for the data sets. 2022 by authors, all rights reserved. -
An in-Depth Analysis on the Cumulative Effect of Co and Sintering Temperatures on the Formaldehyde Sensing Attributes of NiO
In-depth studies are availing to explore and utilize the sensing attributes of p-type NiO nanostructures. However, the surface functionalization of NiO using Co for gas sensing along with varying temperature profile is a novel attempt till date. The research succeeded in synthesizing pure and substituted NiO via co-precipitation route and assessed the sensing capability of the samples by testing with 10 different target gases. The Co doped NiO sintered at 500C exhibited promising sensing performance within a concentration range of 1100ppm, notably achieving a high response of 7817 for 100ppm HCHO at room temperature. The proposed sensor demonstrated rapid response and recovery times (9s and 8s), and it successfully passed stability tests conducted over a 30-day period and repeatability tests consisting of eight cycles. The work paved a way to the implication of the prepared sensor as a breath analyzer to detect lung cancer due to its appreciable formaldehyde sensing characteristics. Graphical Abstract: (Figure presented.) The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024. -
An Enhanced Approximation Algorithm Using Red Black Tree and HashMap for Virtual Machine Placement Problem
The virtual machine placement problem (VMPP) is an np-hard optimization problem in cloud computing that involves efficiently allocating virtual machines (VMs) to physical hosts in such a way that the resource wastage is minimized, and resource usage is optimal while ensuring adequate performance. This paper proposes a modified best-fit approximation algorithm using Red Black Tree (RBT) and HashMap for addressing the VMPP with enhanced computational efficiency in such a way that the active hosts in a given data center remains minimum possible. The proposed algorithm builds up on the existing best-fit approximation algorithm by using RBT and HashMap. The proposed approach considers various attributes such as CPU utilization, memory requirements, and network bandwidth while allocating virtual machines. To evaluate the performance the simulation is done in cloudsim environment with PlanetLab workload. Test cases are considered in both homogeneous and heterogeneous environments and results are taken. Comparative analyses were performed against existing benchmark algorithms in terms of time complexity and resource usage in terms of active hosts. The results demonstrate that the proposed algorithm outperforms the existing algorithms and guarantees time complexity of O(log n) and give better results compared to other algorithms. 2024, The Author(s), under exclusive licence to Springer Nature Singapore Pte Ltd.