Showing papers by "Shiv Nadar University published in 2022"
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TL;DR: In this article, the development status, preparation and modification methods of cellulose composites created by various materials (graphene, fly ash, graphene oxide and bentonite) which evaluates the research development and existing challenges in water treatment.
56 citations
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TL;DR: In this article, a critical review by in-depth analysis from the material side on perovskite oxides for oxygen transport is needed, which would give rise to the fundamental understanding of the impact of various transitional metal elements on oxygen transport performance and stability in a different atmosphere.
42 citations
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TL;DR: A summary of research into the generation of natural bio-based succinic acid (SA) monomer, the development of poly(butylene succinate) (PBS) as biodegradable polymer, PBS-based nanocomposites and their innovative uses is given in this article.
34 citations
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TL;DR: In this paper, the various production techniques for polymer-based graphene derivative nanocomposites in electrochemical glucose detection are discussed, and a detailed analysis of their performance is presented.
14 citations
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TL;DR: In this paper , a simple and ecological synthesis route has been employed for large scale fabrication of self-assembled, sustainable nanostructures on unprocessed and micro imprinted aluminum surfaces named "Nano" and "Hierarchy".
9 citations
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TL;DR: In this paper , the authors used hybrid QM/MM calculations and MD simulations for the OleT enzyme as well as for the structurally analogous enzyme, P450BSβ.
Abstract: Cytochrome P450 peroxygenases use hydrogen peroxide to hydroxylate long-chain fatty acids by bypassing the use of O2 and a redox partner. Among the peroxygenases, P450OleT uniquely performs decarboxylation of fatty acids and production of terminal olefins. This route taken by P450OleT is intriguing, and its importance is augmented by the practical importance of olefin production. As such, this mechanistic choice merits elucidation. To address this puzzle, we use hybrid QM/MM calculations and MD simulations for the OleT enzyme as well as for the structurally analogous enzyme, P450BSβ. The study of P450OleT reveals that the protonated His85 in the wild-type P450OleT plays a crucial role in steering decarboxylation activity by stabilizing the corresponding hydroxoiron(IV) intermediate (Cpd II). In contrast, for P450BSβ in which Q85 replaces H85, the respective Cpd II species is unstable and it reacts readily with the substrate radical by rebound, producing hydroxylation products. As shown, this single-site difference creates in P450OleT a local electric field (LEF), which is significantly higher than that in P450BSβ. In turn, these LEF differences are responsible for the different stabilities of the respective Cpd II/radical intermediates and hence for different functions of the two enzymes. P450BSβ uses the common rebound mechanism and leads to hydroxylation, whereas P450OleT proceeds via decarboxylation and generates terminal olefins. Olefin production projects the power of a single residue to alter the LEF and the enzyme's function.
8 citations
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TL;DR: In this paper , an efficient and reliable methodology is utilized to prepare a GIS-based flood risk map for the Assam region, India using multi-criteria decision analysis (MCDA) and analytical hierarchy process (AHP).
Abstract: Floods are frequently occurring events in the Assam region due to the presence of the Brahmaputra River and the heavy monsoon period. An efficient and reliable methodology is utilized to prepare a GIS-based flood risk map for the Assam region, India. At the regional and administrative level, the flood hazard index (FHI), flood vulnerability index (FVI), and flood risk index (FRI) are developed using multi-criteria decision analysis (MCDA) – analytical hierarchy process (AHP). The selected indicators define the topographical, geological, meteorological, drainage characteristics, land use land cover, and demographical features of Assam. The results show that more than 70%, 57.37%, and 50% of the total area lie in moderate to very high FHI, FVI, and FRI classes, respectively. The proposed methodology can be applied to identify high flood risk zones and to carry out effective flood risk management and mitigation strategies in vulnerable areas.
7 citations
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TL;DR: In this article , the local electric field (LEF) of the enzyme along the reaction axis was proposed as a descriptor for the enzymatic activity using the example of chorismate mutase in its native form and several variants (R90A, R90G, and R90K/C88S).
Abstract: The current theoretical perception of enzymatic activity is highly reliant on the determination of the activation energy of the reactions, which is often calculated using computationally demanding quantum mechanical calculations. With the ever-increasing use of bioengineering techniques that produce too many variants of the same enzyme, a fast and accurate way to study the relative efficiency of enzymes is currently in high demand. Here, we propose the local electric field (LEF) of the enzyme along the reaction axis as a descriptor for the enzymatic activity using the example of chorismate mutase in its native form and several variants (R90A, R90G, and R90K/C88S). The study shows a direct correlation between the calculated enzymatic EF and the enzymatic activity for all the complexes. MD simulations of the Michaelis complex and the transition state analog (TSA) show a stabilizing force on the TSA due to the enzymatic EF. QM/MM and QM-only DFT calculations in the presence of an external electric field (EEF) oriented along the reaction axis show that the electric field can interact with the dipole moment of the TS, thereby stabilizing it and thus lowering the activation energy.
7 citations
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TL;DR: This paper is proposing an abstractive text summarization Deep learning model for Telugu language based on encoder-decoder sequential models with attention mechanism and has got good results measured qualitatively.
Abstract: ive text summarization is the process of constructing semantically relevant shorter sentences which captures the essence of the overall meaning of the source text. It is actually difficult and very time consuming for humans to summarize manually large documents of text. Much of work in abstractive text summarization is being done in English, and almost no significant work has been reported in Telugu abstractive text summarization. So, we would like to propose an abstractive text summarization approach for Telugu language using deep learning. In this paper, we are proposing an abstractive text summarization deep learning model for Telugu language. The proposed architecture is based on encoder–decoder sequential models with attention mechanism. We have applied this model on manually created dataset to generate a one sentence summary of the source text and have got good results measured qualitatively.
6 citations
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TL;DR: In this paper, the authors investigate the interaction between turbulent flow and a gravel-bed that mimics the actual roughness structures of a natural bed and its implication on sediment transport.
6 citations
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TL;DR: In this paper, the authors synthesize Mg-Co-Zn nanoferrites of composition MgxCo0.5Zn 0.5Fe2−xO4 (x = 0.25, 0.75 and 1.0) using a citrate precursor method.
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TL;DR: In this paper, microwave-based hydrothermal treatment was used to develop a durable superhydrophobic aluminium alloy (AA5083), which was effectively tuned through modulation in processing temperatures with the transition from nanofibrils (NF) to densely networked flake-like (DNF) structures.
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TL;DR: In this article , a microwave-based hydrothermal treatment was used to develop a durable superhydrophobic aluminium alloy (AA5083), where the surface morphology was effectively tuned through modulation in processing temperatures with the transition from nanofibrils (NF) to densely networked flake-like structures.
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TL;DR: Sarma et al. as mentioned in this paper constructed the complete structure of human TTF1 protein, using molecular modelling approaches, and the structural stability was determined with molecular dynamics simulations in explicit solvent, and trajectory analyses.
Abstract: Transcription Termination Factor 1 (TTF1) is an essential mammalian protein that regulates transcription, replication fork arrest, DNA damage repair, chromatin remodelling etc. TTF1 interacts with numerous cellular proteins to regulate various cellular phenomena which play a crucial role in maintaining normal cellular physiology, and dysregulation of this protein has been reported to induce oncogenic transformation of the cells. However, despite its key role in many cellular processes, the complete structure of human TTF1 has not been elucidated to date, neither experimentally nor computationally. Therefore, understanding the structure of human TTF1 is crucial for studying its functions and interactions with other cellular factors. The aim of this study was to construct the complete structure of human TTF1 protein, using molecular modelling approaches. Owing to the lack of suitable homologues in the Protein Data Bank (PDB), the complete structure of human TTF1 was constructed by ab initio modelling. The structural stability was determined with molecular dynamics (MD) simulations in explicit solvent, and trajectory analyses. The frequently occurring conformation of human TTF1 was selected by trajectory clustering, and the central residues of this conformation were determined by centrality analyses of the Residue Interaction Network (RIN) of TTF1. Two residue clusters, one in the oligomerization domain and other in the C-terminal domain, were found to be central to the structural stability of human TTF1. To the best of our knowledge, this study is the first to report the complete structure of this essential mammalian protein, and the results obtained herein will provide structural insights for future research including that in cancer biology and related studies.Communicated by Ramaswamy H. Sarma
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TL;DR: In this article , a Coupling game dynamic framework of vaccination choice and compartmental disease transmission model of two strains was explored to understand the influence of human vaccination choice on pathogen competition or strain invasion for vaccine-preventable infectious diseases.
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TL;DR: In this paper , a simple and economical method for synthesizing the luminescent nanocrystals MoS2 using the hydrothermal technique was proposed, which can selectively target and destroy lung cancer cells, especially drug-resistant cells.
Abstract: Ultrasmall MoS2 nanocrystals have unique optoelectronic and catalytic properties that have acquired significant attraction in many areas. We propose here a simple and economical method for synthesizing the luminescent nanocrystals MoS2 using the hydrothermal technique. In addition, the synthesized MoS2 nanocrystals display photoluminescence that is tunable according to size. MoS2 nanocrystals have many advantages, such as stable dispersion, low toxicity and luminescent characteristics, offering their encouraging applicability in biomedical disciplines. In this study, human lung cancer epithelial cells (A549) are used to assess fluorescence imaging of MoS2 nanocrystals. MTT assay, trypan blue assay, flow cytometry and fluorescence imaging results have shown that MoS2 nanocrystals can selectively target and destroy lung cancer cells, especially drug-resistant cells (A549).
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01 Jan 2022TL;DR: In this article, an efficient parking system is proposed to avoid the time wasted while searching for a parking spot in an urban high vehicle density area and make an efficient and automated parking system.
Abstract: In today’s world, where we as humans are constantly aiming towards improving machines and giving them a brain of their own, it is about time that our traffic trends and parking systems become as efficient and automated too. The aim of this paper is to acknowledge the increasing traffic, unorganized parking, and the time wasted while searching for a parking spot in an urban high vehicle density area and make an efficient parking system to avoid the same. Our approach includes the live navigation through our android app, which solves the problem of searching for parking lots in the area. Secondly, an android application is used to show the slots available/occupied in a parking lot. Thirdly, nodes at the parking slot help in making the parking organized. Lastly, an OTP-driven convenient payment method is made for fast functioning of parking exit systems.
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01 Nov 2022TL;DR: In this article , the authors have modified the aluminium surfaces by a coating of graphene oxide (GO) due to its excellent physicochemical properties, water dispersity and low cytotoxicity.
Abstract: Antimicrobial coatings on metallic surfaces are rapidly emerging to combat bacterial pathogens. The excess use of conventional antibiotics increases the number of resistant strains at an alarming rate, which in turn leads to detrimental implications in the healthcare sector. Hence, it is of great importance in developing a new class of material with inherent bactericidal activity and good biocompatibility. In the present study, we have modified the aluminium surfaces by a coating of graphene oxide (GO) due to its excellent physicochemical properties, water dispersity and low cytotoxicity. Coatings were developed through facile and enviornment-friendly transfer method. The antimicrobial properties of GO coated aluminium are investigated against Gram-negative strain E. coli through agar plate counting and ‘Live/Dead’ fluorescence staining. Further, to shed light into the mechanism of antibacterial activity of GO at the molecular level, we have performed X-ray reflectivity (XRR) study considering a phospholipid multilayer as a model system to mimic bacteria cell membrane. Results show a significant bactericidal activity of the GO coatings compared to uncoated aluminium with lower concentration showing slightly better antibacterial property due to higher roughness. The obtained results may pave the way for engineering graphene-based antimicrobial coatings on a material surface using an easy, environment-friendly, cost-effective and straight forward processing route.
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TL;DR: In this paper , morphometric parameters and geomorphic indices for the Assam region are derived from SRTM DEM data of 30 m resolution using GIS to characterize the tectonic activity, which in turn influences the drainage pattern.
Abstract: Assam region is mainly formed by the deposit and erosion process of the Brahmaputra River. The frequency of seismic events results in landform deformation, which highly influences the drainage basin pattern and causes drainage anomalies, having a subsequent effect on the flood distribution pattern. In the present study, morphometric parameters and geomorphic indices for the Assam region are derived from SRTM DEM data of 30 m resolution using GIS to characterize the tectonic activity, which in turn influences the drainage pattern. The indices are classified into three tectonic activity classes, and the average of the classes is combined to generate the indices of relative active tectonics (IRAT). The four classes of IRAT are defined for the study area as (i) very high; Class 1 (1.57–1.80), (ii) high; Class 2 (1.81–2.06), (iii) moderate; Class 3 (2.07–2.26), and (iv) low; Class 4 (2.27–2.30). Class 1 corresponds to basins 1 and 6. Basins 2, 4, and 5 fall under Class 2. Class 3 consists of basins 7, 8, and 9, and Class 4 comprises basins 3 and 10. Results show that most of the study area lies in very high to moderate active tectonic zones and the identified zones are consistent with significant faults and thrusts present in the basins. The combined approach of GIS-based morphometric and geomorphic study allows for identifying deformed landforms resulting from active tectonics. The results can also be employed for the development of watershed management and sustainable land use planning.
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TL;DR: In this paper, the lateral response of a hollow circular caisson embedded in nonlinear soils is modeled by a three-dimensional nonline line model, and the caisson-soil system is analyzed.
Abstract: This paper presents the numerical analysis of the lateral response of hollow circular caisson embedded in nonlinear soils. The caisson–soil system is modeled by a three-dimensional nonline...
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TL;DR: In this article , three phenoxazine-quinoline conjugates (PQ, PQCl and PQBr) are reported, where D and A parts are held in orthogonal orientation around the C-N single bond.
Abstract: Room-temperature phosphorescence (RTP) from organic compounds has attracted increasing attention in the field of data security, sensing, and bioimaging. However, realization of RTP with an aggregate induced phosphorescence (AIP) feature via harvesting supersensitive excited charge transfer triplet (3CT) energy under visible light excitation (VLE) in single-component organic systems at ambient conditions remains unfulfilled. Organic donor-acceptor (D-A) based orthogonal structures can therefore be used to harvest the energy of the 3CT state at ambient conditions under VLE. Here we report three phenoxazine-quinoline conjugates (PQ, PQCl, PQBr), in which D and A parts are held in orthogonal orientation around the C-N single bond; PQCl and PQBr are substituted with halogens (Cl, Br) while PQ has no halogen atom. Spectroscopic studies and quantum chemistry calculations combining reference compounds (Phx, QPP) reveal that all the compounds in film at ambient conditions show fluorescence and green-RTP due to (i) radiative decay of both singlet charge transfer (1CT) and triplet CT (3CT) states under VLE, (ii) energetic nondegeneracy of 1CT and 3CT states (1CT- 3CT, 0.17-0.21 eV), and (iii) spatial separation of highest and lowest unoccupied molecular orbitals. Further, we found in a tetrahydrofuran-water mixture (fw = 90%, v/v) that both PQCl (10-5 M) and PQBr (10-5 M) show concentration-dependent AIP with phosphorescence quantum yields (ϕP) of ∼25% and ∼28%, respectively, whereas aggregate induced quenching (ACQ) was observed in PQ. The phosphorescence lifetimes (τP) of the PQCl and PQBr aggregates were shown to be ∼22-62 μs and ∼22-59 μs, respectively. The ϕP of the powder samples is found to be 0.03% (PQ), 15.6% (PQCl), and 13.0% (PQBr), which are significantly lower than that of the aggregates (10-5 M, fw = 90%, v/v). Film (Zeonex, 0.1 wt %) studies revealed that ϕP of PQ (7.1%) is relatively high, while PQCl and PQBr exhibit relatively low ϕP values (PQCl, 9.7%; PQBr, 8.8%), as compared with that of powder samples. In addition, we found in single-crystal X-ray analysis that multiple noncovalent interactions along with halogen···halogen (Cl···Cl) interactions between the neighboring molecules play an important role to stabilize the 3CT caused by increased rigidity of the molecular backbone. This design principle reveals a method to understand nondegeneracy of 1CT and 3CT states, and RTP with a concentration-dependent AIP effect using halogen substituted twisted donor-acceptor conjugates.
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TL;DR: Submerged vanes have been used extensively for sediment deflection in river training tasks as discussed by the authors , such as river bends protection, sediment exclusion at water intakes, improving safety at bridges on waterways, and improving inland navigation.
Abstract: Diverting or deflecting sediments is an essential part of river training. Under the effect of an induced helical motion, the submerged vanes are best known for deflecting sediments. This study presents current state-of-the-art information on employing submerged vanes for sediment deflection, as well as concluding notes outlining the current knowledge’s limitations and suggestions for future research on sediment deflection using submerged vanes. The analytical background for basic physics of submerged vanes’ operation is first described. The paper then moves on to a thorough examination of vane design parameters based on analytical relationships. A brief overview of the applications of submerged vanes is also included in the paper. A review of recent studies aims at designing a layout of submerged vanes to assist in river training tasks, such as river bends protection, sediment exclusion at water intakes, improving safety at bridges on waterways, improving inland navigation is provided to this end. The study also presented a future program of research on submerged vanes for improving inland navigation in braided rivers. The major lag in literature is a lack of information on macro turbulence and the associated sediment motion induced by the wake of the submerged vane.
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TL;DR: In this paper , the authors used transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and atomic force microscopy to study ethanol-water mixtures.
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TL;DR: The virtual element method as discussed by the authors is a Galerkin approach that is applicable to meshes that consist of arbitrarily-shaped polygonal and polyhedral (simple and nonsimple) elements.
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TL;DR: In this paper , Bézier extraction of NURBS-based basis functions is implemented in discretization of domain for approximating both unknown field solution and geometries, and numerical results are first validated from analytical ones and then additionally, few numerical problems are solved for calculating the fracture parameters in terms of normalized intensity factors with respect to shear loads, electrical loads, crack orientation angle and angle of polarization.
Abstract: This work presents analyses of interfacial crack in piezoelectrics bimaterial plate under electromechanical loading environment by extended isogeometric analysis (XIGA) approach using Bézier extraction of NURBS. Asymptotic crack–tip branch functions and discontinuous Heaviside function are implemented for local enrichment in the approximation of isogeometric analysis for capturing singularity at cracktip and discontinuity across surfaces of a crack. Bézier extraction of NURBS–based basis functions are implemented in discretization of domain for approximating both unknown field solution and geometries. The Bézier extraction operation decomposes the NURBS basis functions into a set of linear combination of Bernstein polynomials and a set of C0–continuity Bézier elements. Domain–form interaction integral is implemented to obtain generalized fracture parameters. To assess the robustness and accuracy in results obtained from XIGA, numerical results are first validated from analytical ones and then additionally, few numerical problems are solved for calculating the fracture parameters in terms of normalized intensity factors with respect to shear loads, electrical loads, crack orientation angle and angle of polarization.
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TL;DR: In this paper , the authors focus on one Ashram in India and the importance of the Samadhi shrine in the life of its members, arguing that the shrine constitutes the spatial heart of an otherwise spatially dispersed Ashram.
Abstract: Tombs of gurus and religious leaders are central to the consolidation of religious communities through memorialisation and the public performance of rituals. In Hindu and neo-Hindu religious movements, the guru’s samadhi is one such important sacred space. Based on ethnographic fieldwork, this article focuses on one Ashram in India and the importance of the Samadhi shrine in the life of its members. The article argues that the Samadhi constitutes the spatial heart of an otherwise spatially dispersed Ashram. It is at the Samadhi that the devotees become present to the gurus and one another, creating a community of devotees through both a linear ‘chain of memory’ and lateral ‘intimacy grids’. At the same time, the creation of such a community grapples with the wider locational specificities of the Ashram and the politics of making it a home.
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06 Jul 2022TL;DR: In this paper , a single site mutation (D321G) far from the capping loop can induce a large conformational change in the CCL to recognize different substrates for different functions.
Abstract: The adaptability of the active site to amplify the secondary function is supposed to be the fundamental cause of the promiscuity and the evolution of new functions in the enzymes. In most cases, mutations occur close to the active site and/or in the catalytic site to change the active site plasticity to accommodate the non-native substrate. In the present study, using MD simulations and hybrid QM/MM calculations, we have shown a way to enhance the promiscuity, i.e., the allostery-driven promiscuity. Using a case study of the AEE enzyme where the capping loop recognizes the substrate, herein, we show that a single site mutation (D321G) far from the capping loop can induce a large conformational change in the capping loop to recognize different substrates for different functions. The QM/MM calculations for the WT and mutated enzyme provide a first validation of the mechanism of 1,1-proton transfer and dehydration by the AEE enzyme. Since AEE epimerase possesses a highly conserved TIM-barrel fold, we believe that our study provides a crucial lead to understanding the mechanism of emergence of secondary function which can be useful to repurpose ancient enzymes for modern usage.