Ankita Bisht
@wit.ac.in
Assistant Professor, Department of Mechanical Engineering
Women Institute of Technology Dehradun, India
RESEARCH INTERESTS
Multiscale-mechanics and nano-mechanics of composite materials
Effective dispersion of nanofillers and their synergy in composites
Evaluating out of plane/ transverse properties of nanofiller modified FRPs
Fabrication, characterization, mechanical and thermo-mechanical testing of composites
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Souvik Ghosh, Swati Haldar, Sumeet Gupta, Ankita Bisht, Samrat Chauhan, Viney Kumar, Partha Roy, and Debrupa Lahiri
American Chemical Society (ACS)
Fascicular rearrangement of an injured peripheral nerve requires reconnection of nerve sprouts from anterior and Bungner bands from distal sides of the lesion, failing to which leads to inefficient...
Ankita Bisht, S.S. Samant, Satish Jaiswal, Kinshuk Dasgupta, and Debrupa Lahiri
Elsevier BV
Abstract Graphene (Gr) is one of the most preferred reinforcement for polymer matrix, due to its large surface area. However, poor dispersion, due to stacking of Gr sheets, restricts their potential as reinforcement. In the present study, exfoliation of multi-layered graphene sheets is achieved in the presence of nanodiamond (ND), using ultrasonication. High-resolution electron micrographs clearly reveal the role played by ND in hindering restacking of graphene. SPM imaging further quantified exfoliation by measuring the thickness for different combinations of Gr:ND. Improved exfoliation of Gr increases both tensile strength and strain by ~71% and ~113%, respectively, for >0.5 wt% Gr content. Fracture toughness is improved by ~150% with Gr, and an additional 44% with ND decorated Gr. Numerical analysis further confirms the effect of ND assisted exfoliation of Gr in toughening behavior of the composite, which can be explained in terms of improved total interface area, helping in better load transfer.
Ankita Bisht, Kinshuk Dasgupta, and Debrupa Lahiri
Elsevier BV
Abstract Addition of carbon nanotubes (CNT) to Graphene (Gr) is seen to have synergistic effect as reinforcement to polymer matrix. This is possible as CNTs inhibit stacking of Gr sheets, thus providing larger surface area nanophase to get bonded with polymer matrix and providing mechanical support through load sharing and crack growth inhibition. However, tube like morphology and high aspect ratio of CNT often lead to entanglement, which restricts their effect in exfoliating Gr. The aim of the present study is to investigate the potential of ND in improving the synergistic effect of Gr-CNT hybrid as a reinforcement to epoxy matrix. This study utilizes the power of ultrasonication technique, which is very simple and scalable, for dispersing and incorporating nanofillers into epoxy matrix. Addition of ND to Gr-CNT epoxy composite improved the tensile strength from ~46% with 0.5 wt% (75Gr:25ND) to ~51% with 0.8 wt% (25Gr:25CNT:50ND) as compared to neat epoxy. While the fracture toughness improved from ~140% with 0.5 wt% (25Gr:75CNT) to 165% with 0.8 wt% (25Gr:50CNT:25ND). Fractured surfaces of composites revealed improved dispersion and strong interfacial interaction with addition of ND to Gr-CNT hybrid. NDs attaches to the surface of Gr inhibit the stacking of Gr sheets by restricting π-π stabilization. NDs also help in bridging the ends of CNTs together into long chains, thereby increasing the aspect ratio of the fiber like reinforcement. This increases the total available surface area of CNTs and Gr, to interact with epoxy matrix, improves the overall efficiency of Gr-CNT hybrid as a reinforcement, resulting into improvement in mechanical properties of the composite structure.
Ankita Bisht, Mohit Dua, Shelza Dua, and Priyanka Jaroli
Walter de Gruyter GmbH
Abstract The paper presents an approach to encrypt the color images using bit-level permutation and alternate logistic map. The proposed method initially segregates the color image into red, green, and blue channels, transposes the segregated channels from the pixel-plane to bit-plane, and scrambles the bit-plane matrix using Arnold cat map (ACM). Finally, the red, blue, and green channels of the scrambled image are confused and diffused by applying alternate logistic map that uses a four-dimensional Lorenz system to generate a pseudorandom number sequence for the three channels. The parameters of ACM are generated with the help of Logistic-Sine map and Logistic-Tent map. The intensity values of scrambled pixels are altered by Tent-Sine map. One-dimensional and two-dimensional logistic maps are used for alternate logistic map implementation. The performance and security parameters histogram, correlation distribution, correlation coefficient, entropy, number of pixel change rate, and unified averaged changed intensity are computed to show the potential of the proposed encryption technique.
Ankita Bisht, Kinshuk Dasgupta, and Debrupa Lahiri
Elsevier BV
Abstract Carbon fiber epoxy composites are being used in numerous structural applications. However, fracture toughness of these composites is always less than expected. Therefore, potential of nanofillers in improving the fracture toughness of these composites, with, three different morphologies, i.e., Gr (sheet), CNT (tube) and nanodiamond (particle), in a well-connected 3D network is evaluated in this study. Both, interlaminar and intralaminar mode I fracture toughness, revealed improvement of ~260% and ~53%, respectively, with 25Gr:50CNT:25ND CF-epoxy, as compared to CF-epoxy composite. Marking a total improvement of ~1523% over pure epoxy on intralaminar fracture toughness. The composites were also assessed for tensile and interlaminar shear strength. An improvement of ~60% and ~16%, respectively, is noted with the addition of nanofillers. SEM analysis for delaminated and fractured surfaces revealed the toughening mechanism to be the high surface area of nanofillers, offering strong adhesion between matrix and fiber, along with improved matrix toughness.
Ankita Bisht, Vijayesh Kumar, Palash Chandra Maity, Indranil Lahiri, and Debrupa Lahiri
Elsevier BV
Abstract Polymer composites with suitable reinforcement can offer UV-shielding ability and strength simultaneously. Such material systems are being researched for many commercial applications, including window shields and automobiles. However, the inherent challenge is retaining transparency, while using reinforcement for adequate strength and UV-shielding. In this study, boron-nitride nanoflakes (BN) were reinforced in poly(methyl-methacrylate) (PMMA) to synthesize a strong and transparent sheet for structures for UV-shielding purpose. BN nanoflakes were amine functionalized and added for a range of content (0.1–3 wt%). Uniform dispersion and strong interfacial interaction led to efficient load transfer from matrix to reinforcement, thus increasing strength and modulus by 155% and 148%, respectively, with 2 wt% BN. UV-B and UV-C shielding properties improved as compared to PMMA for all composition. Addition of 0.5 wt% BN to PMMA offered improvement in blocking UV-wavelength by 325%, along with high transparency of ~65% to visible light.
Ankita Bisht, R. Manoj Kumar, Kinshuk Dasgupta, and Debrupa Lahiri
Elsevier BV
Abstract The present study has taken an initiative to understand the distribution of nanophase reinforcement in polymer matrix and their behaviour during loading, using 2D modulus mapping. The composite system, being studied here, is a nanodiamond reinforced epoxy resin matrix. Modulus Mapping gives an idea of distribution of nanodiamond in matrix, in terms of spatial distribution of micron level higher modulus regions in epoxy matrix. The modulus mapping studies, carried out on composites with and without application of uniaxial tensile stresses, reveals the active role being played by nanodiamond in modulating the mechanical behaviour of the epoxy matrix and the evolution of distribution of the former with application of stress. Hardness and elastic modulus of epoxy is improved by ∼470% and ∼94% with 1 wt% nanodiamond. The stiffening effect of nanodiamond dispersed in epoxy matrix, evaluated through experiment is also in concurrence with results simulated using finite element method (FEM) of the representative volume element (RVE). Tensile strength and fracture toughness also showed an improvement of ∼56% and ∼85%, respectively, with 0.3 wt% ND. Interestingly, % strain (at break) also increased by ∼66%. TEM showed good dispersion and strong interaction of NDs with epoxy matrix. SEM analysis validates crack pinning and crack deflection as dominant toughening mechanism, while, efficient load sharing between ND and epoxy is found as main strengthening mechanism. As a whole, this study develops 2D modulus mapping technique as a generalized tool for evaluating the quality of dispersion of the nanoscale reinforcement phases and their role in mechanical behaviour of the macro-scale composite structures.
K Khati, I Joshi, A Bisht, and M G H Zaidi
Springer Science and Business Media LLC
Conducting polymers have recently been employed with metal derivative macromolecules that have led to great improvement in the field of supercapacitor materials. The current work reports on the synthesis of a novel class of haemoglobin/polyindole composites (HPCs) through doping of haemoglobin (Hb) into a polyindole (PIN) matrix. HPCs with enhanced electrocapacitive performance were prepared through a cationic surfactant-assisted dilute solution polymerization of indole (IN) in the presence of Hb at various concentrations ranging from 10 to 30% (w/w) and ferric chloride ($$\\hbox {FeCl}_{3}$$FeCl3) as an oxidant. The HPCs were characterized through Fourier transform infrared spectra, scanning electron microscopy and simultaneous thermogravimetric analysis. Electrochemical capacitance ($$C_{\\mathrm{s}}$$Cs, $$\\hbox {F g}^{-1}$$Fg-1) of graphite-based electrodes fabricated from HPCs over stainless steel in the presence of sulphonated polysulphone as a binder has been investigated in KOH solution (1.0 M) with reference to Ag/AgCl at a scan rate ($$\\hbox {V s}^{-1}$$Vs-1) ranging from 0.001 to 0.2. HPCs with 30% (w/w) of Hb have shown the highest $$C_{\\mathrm{s}}$$Cs of 294.00 as compared with 112.00 for pure PIN at a scan rate of $$0.001 \\hbox { V s}^{-1}$$0.001Vs-1. Successive scans of HPC electrodes show a capacitive decline of $${\\sim }2\\%$$∼2% during the first 1000 cycles at a scan rate of $$0.1 \\hbox { V s}^{-1}$$0.1Vs-1 in KOH (1.0 M), which indicates the appreciable electrochemical cyclic stability of the HPCs over PIN. Thus, the fabricated HPCs may serve as potential electrode material for development of electrochemical supercapacitors.
Ankita Bisht, Priyanka Jaroli, Mohit Dua, and Shelza Dua
IEEE
The paper presents a symmetric approach to encrypt multiple images with aid of newer chaotic functions which help in producing larger chaotic range and Arnold cat map. The encryption process comprises of two-phase: permutation and diffusion. The bit-level permutation is performed using expand and shrink strategy and for pixel shuffling the Arnold cat map is employed. In diffusion phase, the intensity of image pixel is modified. Firstly, using the expansion process images are partitioned into their even and odd bit-planes. Then, a bigger image is formed by the amalgamation of partitioned plane-bits. Secondly, the permutation phase is employed with help of chaotic function. Arnold cat map and newer chaotic function logistic-sine and logistic-tent map generates the sequence of random numbers. Finally, in diffusion phase, tent-sine map is used to modify the intensity value of the image pixel and the shrink process produced the encrypted images. Initial values of chaotic functions are used for encryption as well as for decryption of images. The performance measures are computed to show the efficiency and attack resistance capacity of encryption technique.
Priyanka Jaroli, Ankita Bisht, Mohit Dua, and Shelza Dua
IEEE
A color image encryption based on four dimensional differential equations and Arnold map (AM). High dimensional cryptosystem are increased the complexity of the encryption procedure. Initially, the four dimensional equations are used for key generation and this equation increases the range of the chaotic random values. These equations are based on the low dimensional differential equation. Secondly, the diffusion process is used for the diffuse the pixel values of the plain image. At last the AM is used for mixed or shuffle the image pixels and it is used with the parameter. Finally, the encrypted R, G and B cannel is obtained. Experimental and simulation results show that the encryption algorithm is crack the adjacent correlation between the image pixels and increase the security of the image.
Ankita Bisht, Kinshuk Dasgupta, and Debrupa Lahiri
Wiley
Graphene-nanoplateles (Gr) and multiwalled carbon nanotubes (CNTs) reinforced epoxy based composites were fabricated using ultrasonication, a strong tool for effective dispersion of Gr/CNTs in epoxy. The effect of individual addition of two different nanofillers (Gr and CNT) in epoxy matrix, for a range of nanofiller content (0.1–1 wt %), has been investigated in this study. This study compares mechanical and thermomechanical behavior of Gr and CNT reinforced epoxy. Gr reinforcement offers higher improvement in strength, Young's modulus, and hardness than CNT, at ≤0.2 wt %. However, mode-I fracture toughness shows different trend. The maximum improvement in fracture toughness observed for epoxy-Gr composite was 102% (with 0.3 wt % loading of Gr) and the same for epoxy-CNT composite was 152% (with 0.5 wt % loading of CNT). Thorough microstructural studies are performed to evaluate dispersion, strengthening, and toughening mechanisms, active with different nanofillers. The results obtained from all the studies are thoroughly analyzed to comprehend the effect of nanofillers, individually, on the performance of the composites in structural applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46101.
Ankita Bisht, Riya Bora, Goutam Saini, Pushkar Shukla, and Balasubrmanian Raman
IEEE
Classical dance forms are an integral part of the Indian culture and heritage. Therefore, preserving and comprehending these dance forms is a relevant problem in context with the digital preservation of the Indian Heritage. In this paper, we propose a novel framework to classify Indian classical dance forms from videos. The representations are then extracted through Deep Convolution Neural Network(DCNN) and Optical Flow. Moreover these representations are trained on a multi-class linear support vector machine(SVM). Furthermore, a novel dataset is introduced to evaluate the performance of the proposed framework. The framework is able to achieve the accuracy of 75.83 % when tested on 211 videos.
Riya Bora, Ankita Bisht, Aradhya Saini, Tanu Gupta, and Ankush Mittal
IEEE
Communication is an important part of our day to day lives. It is an essential means of conveying our emotions through gestures as well as verbally. However, communication and recognition of gestures becomes a problem for humans with speaking and hearing impairment. For this very purpose sign language is used. Indian Sign Language (ISL) is resourceful in India for helping such people. The paper proposes a novel technique to identify gestures defined for the English alphabets listed in the Indian Sign Language. The proposed techniques relies on multiple representations namely HOG, GIST and BSIF. A random forest classifier is used for classifying different gestures with the aid of the combined feature vector. The results of the proposed techniques were tested on a ISL hand gesture database and were compared with the existing solutions. The technique outperformed the existing solutions resulting in an accuracy of 92.20%.
Ankita Bisht, Vijayesh Kumar, Lu Hua Li, Ying Chen, Arvind Agarwal, and Debrupa Lahiri
Elsevier BV
Abstract The effect of rolling and annealing on boron nitride nanotube (BNNTs) reinforced aluminum- composites is investigated in this study. Composites were fabricated via conventional sintering method with 0, 2 & 5 wt% BNNT addition in aluminum matrix. Addition of 2 wt% BNNT improved hardness and elastic modulus by 23% and 18%, respectively. Rolling the same composite at 200 °C with 60% reduction in single pass improved modulus and hardness of the composite by 60% and 31%, respectively, over Al. Addition of 5 wt% BNNT led to reduced properties due to agglomeration, which on rolling developed cracks. Annealing the rolled Al-BNNT composite further led to an improvement in strength and ductility. Annealed Al-2BNNT showed highest improvement in strength of 41% and 110% over rolled and sintered condition, respectively. In addition, the same composition has recorded 157% improvement in toughness in annealed condition, as compared to rolled condition. Uniformly distributed BNNTs restricted grain growth and grain boundary migration due to pinning, leading to presence of additional grain boundaries inside the old grains thus improving the strength further. Uniform distribution of BNNT is the prime reason behind the improved properties of Al-BNNT composites.
Ankita Bisht, Mohit Dua, and Shelza Dua
Springer Science and Business Media LLC
Due to recent advances in network technology, it has become easier to send multiple images together. Hence, image encryption using multiple images is an emerging area of interest amidst researchers. The paper proposes a multiple-image encryption technique based on the chaotic confusion-diffusion strategy and chaotic Discrete Fractional Random Transform (DFRNT). Initially, odd and even bits of three input images (M × N) are separated and a composite image (3M × 2N) is derived by combining the even and odd bits of every image. Secondly, chaotic confusion-diffusion strategy using four chaotic maps Arnold Cat Map (ACM), Logistic-Tent Map (LTM), Logistic-Sine Map (LSM) and Tent-Sine Map (TSM) is applied to scramble and diffuse the pixel values of the composite image. Thereafter, three diffused images are extracted from the diffused composite image. Finally, chaotic DFRNT uses Tent-Sine Map (TSM) to generate the random kernel transform matrix for itself and encrypt the extracted images into a single image. The parameters Histogram, Correlation distribution (CD), Correlation Coefficient (CC), Entropy, Number of Pixel Change Rate (NPCR) and Unified Averaged Changed Intensity (UACI) have been computed to show the potential of the proposed encryption technique.
Andy Nieto, Ankita Bisht, Debrupa Lahiri, Cheng Zhang, and Arvind Agarwal
Informa UK Limited
ABSTRACT This review critically examines the current state of graphene reinforced metal (GNP-MMC) and ceramic matrix composites (GNP-CMC). The use of graphene as reinforcement for structural materials is motivated by their exceptional mechanical/functional properties and their unique physical/chemical characteristics. This review focuses on MMCs and CMCs because of their technological importance for structural applications and the unique challenges associated with developing high-temperature composites with nanoparticle reinforcements. The review discusses processing techniques, effects of graphene on the mechanical behaviour of GNP-MMCs and GNP-CMCs, including early studies on the tribological performance of graphene-reinforced composites, where graphene has shown signs of serving as a protective and lubricious phase. Additionally, the unique functional properties endowed by graphene to GNP-MMCs and GNP-CMCs, such as enhanced thermal/electrical conductivity, improved oxidation resistance, and excellent biocompatibility are overviewed. Directions for future research endeavours that are needed to advance the field and to propel technological maturation are provided.
Ankita Bisht, Mukul Srivastava, R. Manoj Kumar, Indranil Lahiri, and Debrupa Lahiri
Elsevier BV
Abstract Graphene nanoplatelets (GNP) reinforced aluminum matrix composites, with ≤5 wt% GNP content, were synthesized by spark plasma sintering (SPS). GNPs were found to withstand severe conditions of high pressure and temperature during processing. Strength of composite was observed to be depending on the content and uniform dispersion of GNP in aluminum matrix, as verified by scanning electron micrographs. X-ray diffraction analysis confirmed that no reaction products exist at Al-GNP interface in significant amount. Instrumented indentation studies revealed improvement in hardness by 21.4% with 1 wt% GNP. This is due to the presence of stronger reinforcement, which provides high resistance to matrix against deformation. Improvement in yield strength and tensile strength was 84.5% and 54.8%, respectively, with 1 wt% GNP reinforcement. Properties deteriorated at higher concentration due to agglomeration of GNP. Reinforcing effect of GNPs, in terms of strengthening of composite, is found to be dominated by Orowan strengthening mechanism. Pinning of grains boundaries by GNPs led to uniform grain size distribution in the composites structure. Overall, graphene reinforcement has offered 86% improvement in specific strength of aluminum matrix.
V. K. Singh, G. Bansal, P. Negi, and A. Bisht
ASTM International
A hybrid composite consisting of jute fiber-almond shell particle reinforced in epoxy resin modified with 1 weight percentage (wt.%) depolymerised natural rubber (DNR) was fabricated using hand lay-up technique. In the present investigation, we modified the composite by fabricating a composite by filling it with a mixture of almond shell particle and jute fiber, keeping total reinforcement wt. % fixed to 20 wt. %, but varying the ratio of jute fiber and almond shell particle in the manner almond/jute: 100/0, 75/25, 50/50, 25/75, 0/100. Through testings and experimentations, it was concluded that flexural strength is improved by 26.75 %. Through SEM, how the particles and fiber are dispersed in the matrix, how they are bonded to matrix or each other, how at higher wt. % fibers or particles form clusters and effect bonding, with increase in length, how fiber defect increases and composite failure due to fiber pull out or splitting of fiber increases, was seen and justified our results. Thus, it was concluded that 15 wt. % almond shell particle and 5 wt. % treated jute fiber having fiber length 10 mm filled in epoxy modified with 1 wt. % DNR gave the optimum results from various combinations. As such, properties have significantly improved for hybrid composite as compared to pure fiber/ pure particle based composite.
Mayank Agarwal, Mohamand Arif, Ankita Bisht, Vinay K. Singh, and Sunanda Biswas
Walter de Gruyter GmbH
AbstractAn epoxy resin (EP) matrix has been modified with depolymerized natural rubber (DNR). The 0.5, 1.0, 1.5, 2.0, and 2.5 wt% DNR-filled epoxy were used for the present investigation. The primary aim of this development is to scrutinize the mechanical properties of such cured epoxy filled with DNR. When the rubber content was low, the mechanical strength was low and the free volume of DNR in epoxy matrix was less. With the increase in rubber content, the free volume of rubber in the composite increases and the mechanical strength increases; however, after a specific weight percentage of rubber, if we increase the amount of rubber, the mechanical strength decreases and the free volume of rubber in the composite increases quickly, but with the increase in DNR weight percentage in epoxy matrix, the hardness decreases. The scanning electron microscopy (SEM) results justified the results obtained from the mechanical tests.