Abstract: This presentation is on the existence of unique solution of Initial Value Problems (IVPs) and numerical methods related to Fractional Differential Equations (FDEs), Stochastic Differential Equations (SDEs), and Fractional Stochastic Differential Equations (FSDEs)

Abstract: In this presentation, we apply a three-step two-grid finite element Galerkin method based on Newton’s type iteration to the two-dimensional time-dependent Boussinesq system of equations. We achieve optimal error estimates for the velocity in L^∞(L²)-norm, when h = O(H^2−δ ) and in L^∞(¹)-norm, when h = O(H^4−δ), and for the pressure in L^∞(L²)-norm, when h = O(H^4−δ ) with δ > 0 arbitrarily small and H, h coarse and fine mesh parameters, respectively. Furthermore, we derive optimal error estimates for the temperature in L^∞(L²)-norm, when h = O(H^2−δ ) and in L^∞(H¹)-norm, when h = O(H^4−δ ). We further establish that under the smallness condition on the data, the two-grid error estimates hold uniformly in time. Then, we employ a backward Euler method in the time direction to achieve complete discretization and derive fully discrete error estimates. Finally, we conduct numerical experiments to confirm the theoretical findings and demonstrate the performance of the proposed scheme.

Abstract: Let Sg denote a closed oriented surface of genus g ≥ 2. A set Ω = {c1, . . . , cd} of pairwise non-homotopic simple closed curves on Sg is called a filling system or simply a filling of Sg , if Sg \ Ω is a union of ℓ topological discs for some ℓ ≥ 1. For 1 ≤ i ≤ d, let Tci denotes the Dehn twist along ci. In this article, we show that for each d ≥ 2, there exists a filling Ω = {c1, c2, . . . , cd} of Sg such that the group ⟨Tc1 , Tc2 , . . . , Tcd ⟩ is isomorphic to the free group of rank d.

Abstract: In this work, we developed and analyzed time-fractional linear partial differential/integro differential equations with non-self-adjoint elliptic parts having space-time dependent coefficients. A numerical scheme is analyzed using the non-uniform implicit-explicit L1 finite element method (IMEX-L1-FEM) to approximate the solution of such a class of time-fractional PDEs/PIDEs. The proposed method non-uniform IMEX-L1-FEM is a combination of an IMEX-L1 method on graded mesh in the temporal direction and a finite element method in the spatial direction. The optimal convergence analysis of proposed method have been obtained. A few numerical experiments will be provided which will be helpful to demonstrate our theoretical findings.

Abstract: For construction projects, understanding soil heterogeneity is crucial to ensure a strong foundation and prevent failures like the Mahad Bridge and Kolkata Flyover collapses in 2016. Understanding spatial correlation in soil properties is important, but estimating the scale of fluctuation (SOF) using CPT or SPT data is challenging due to limited site information. By employing advanced techniques such as machine learning, we can model soil heterogeneity and obtain a three-dimensional understanding of soil structure, reducing the risk of future potential loss and casualties. To address this, we present a CNN-based ML model that predicts vertical SOF values using SPT N data from borehole depth. The calibrated model exhibits impressive accuracy, with an MSE of 0.007 and an R-value of 0.9. This makes it a valuable tool for calculating SOF in real-site projects like 7 km long bridge over the Brahmaputra River. Comparative analysis against traditional methods (ACF, RICE) and other ML algorithms further validates the model's performance. Furthermore, accuracy and performance of the model was enhanced through refinement by data assimilation. Future work entails extending the study to incorporate CNN2 and CNN3 models for horizontal SOF estimation. With these advancements, we can deepen our understanding of soil behavior and improve geotechnical assessments for a range of construction projects. This study meets sustainable development goals (UN SDGs) 9 & 11- industry-innovation-infrastructure, sustainable cities.

Abstract: Diabetes is one of the most severe health diseases in the world. More than 150 million people worldwide suffer from diabetes caused by an abnormal glucose concentration in their blood and tissues. The analysis of glucose levels in the body is significant, primarily due to diabetes mellitus. Therefore, accurately detecting blood glucose is crucial for diagnosing, treating, and managing diabetes. Diabetic patients can self-manage their condition by monitoring their glucose levels. The electrochemical glucose biosensor has several advantages, including recognizing glucose specifically, low price, ease of sensor manufacture, correctness, portability, and easy operation. We have developed glassy carbon electrodes (GCE) with conventional carbon-micro-electromechanical (C-MEMS) procedures for glucose sensing. SU-8 photoresist was used as the carbon precursor. The fabricated C-MEMS-derived GCE surface has been functionalized with chitosan and glucose oxidase. Glucose oxidase is a well-known enzyme for oxidizing glucose into gluconic acid and H2O2. This reaction kinetics has been recorded with increasing glucose concentration using electrochemical analysis. In summary, we have presented an electrochemical glucose biosensor in a single-step immobilization protocol of glucose oxidase on the glassy carbon electrode (GCE) surface and obtained satisfactory responses for 1 mM to 10 mM glucose solutions.

Abstract: A generalized spatial modulation (GSM) in a full duplex system equipped with a two-way relay channel (FD-GSM-TWRC) is proposed. By adapting the observation model to the use of a compressive sensing framework, we propose two receiver algorithms: structured complex orthogonal matching pursuit (S-COMP) and structured ordered block OMP (S-OBOMP). We demonstrate that FD-GSM-TWRC offers the best possible trade-off between bit-error rate (BER) performance, throughput, and computational complexity when used with the proposed receiver algorithms.

Abstract: Intelligent Reflection Surface (IRS) is going to play a crucial role in future wireless communication (B5G or 6G). IRS enables the strategic manipulation of radio signal propagation within wireless networks as it is able to dynamically change wireless channels to improve communication performance by carefully adjusting the signal reflection using a large number of inexpensive passive reflecting devices. As a result, it is anticipated that the new IRS-assisted hybrid wireless network, which consists of both active and passive components, would be very promising for achieving a sustained capacity expansion cost-effectively in the future. Despite its enormous promise, IRS must overcome new obstacles before it can be effectively used in wireless networks. These obstacles include reflection optimizations, channel estimation, and deployment from the standpoint of communication design. To solve the aforementioned challenges, we give an instructional overview of IRS-aided wireless communications in this poster presentation. We also go into detail about the hardware design, practical limitations, and several intriguing applications in wireless networks. Additionally, we identify crucial perspectives worthy of additional research in future wireless communications.

Abstract: In recent times, a technique known as algorithm unrolling has enabled the connection of iterative algorithms with neural networks for solving linear inverse problems. We introduce a reduced parameter denoiser to enhance image quality using less learnable parameters in the unrolling architecture. Our parameter-reduced denoiser reduces the number of parameters by 3.84 times compared with ResUNet and improves computational efficiency and storage requirements. We unroll the plug-and-play algorithm by employing a three-operator splitting formulation for Poisson, which enables the complete training of the unrolled network. Our modified model surpasses existing state-of-the-art deblurring methods, effectively handling photon shot noise to significantly enhance image quality in low-light conditions.

Abstract: Finding an algorithm to solve an ill-posed linear inverse problem is a thrust area of research. The fast iterative shrinkage thresholding algorithm (FISTA) is a popular algorithm for inverse problems, leading to many improvements and extensions. We have proposed an enhancement to the basic framework for FISTA through an accelerated gradient descent with a proper proximal operation. We have studied the effect of accelerated gradient descent in the presence of noise, which helps us identify the importance of a proper proximal operation to avoid noise incursion. We have provided the theoretical convergence of enhanced FISTA for a fixed step size. Using the image deblurring application, we have demonstrated the effectiveness of the enhancement in the presence of strong noise. The image deblurring results show that the enhanced FISTA (EFISTA) has a superior execution speed with similar reconstruction performances as its predecessors.

Abstract: This MEMS sensor is designed to be used in industry for high pressure application.This design provides a unique pressure and stress range of sensor .This sensor will be fabricated and applied for patent.

Abstract: Air pollution is the major concern as it is the contamination of atmospheric air by harmful and toxic gases, chemicals, physical or biological agent that modifies the natural characteristics of the atmosphere. It can be both man-made and natural. Most of the air pollution is created by humans, which takes the form of exhaust from planes, cars or aerosol cans and factory emissions. Due to all these sources mentioned, man-made and natural, there are toxic gases like carbon-di-oxide, carbon monoxide, sulphur oxides, nitrogen oxides enter into the atmosphere which is hazardous to human health and causes damage to environment. Hence, it is important to detect these gases and control their emission into the atmosphere. The methods to detect and treat the lower oxides of nitrogen are available in the market, whereas, detection of higher nitrogen oxides like N₂O₄ and N₂O₅ is under research. Therefore, fabrication of an efficient, inexpensive and compact sensor is pressing priority. In this work, an effort to design a cost-effective, fast-response Gas Sensor to detect N₂O₄ and N₂O₅ gases produced in vehicular and Industrial exhaust is made. Various pre combustion and post combustion techniques are available for mitigating these harmful gases from diesel engine exhaust.

Abstract: We present a simple approach for deterministically creating quantum-light emitters in a WS₂ monolayer via transferring onto spin-coated SiO₂ nanoparticles acting as local stressors leading to the emission of single photons due to localization of excitons.

Abstract: Search for new topological quantum materials is the demand to achieve substantial growth topological phase of matter. In this search process, theoretical prediction is crucial, besides the obvious experimental verification. The divination of topological properties in already well-known narrow-gap semiconductors is flourishing in quantum material science. We revisited the semiconductor compound in the chalcopyrite series, some of which were potential topological materials. Using this density functional theory-based first-principles calculations, we report a strong topologically nontrivial phase in chalcopyrite ZnGeSb₂, which can act as a model system of strained HgTe. The estimates reveal the non-zero topological invariant (Z₂) Dirac cone crossing in the surface spectral functions with spin-momentum locked spin texture. We also report the tunable topological properties from nontrivial to trivial phases under moderate hydrostatic pressure within ≈7 GPa. A minor modification of a lattice parameter is enough to achieve this topological phase transition easily accomplished in an experimental lab. We have incorporated the discontinuity in the tetragonal distortion of non-centrosymmetric ZnGeSb₂ to drive the topological quantum phase transition.

Abstract: Most widely investigated transition-metal dichalcogenides (TMDs) in the monolayer (ML) regimes host single photon emitters, and therefore they are emerging as an intriguing quantum photonic platform. Various methods of strain engineering have been utilized for creating/inducing the quantum emitters in TMDs at deterministic locations. Here, we discuss a simple and cost-effective approach to introduce strain in 2D materials. We transfer ML WS₂ on spin-coated nanoparticles (NPs) whose locations are priori known via SEM imaging. These spatially isolated NPs act as local strain-inducers for creating single photon emitters at deterministic locations. We also demonstrate that the low-temperature annealing of this photonic heterostructure in the vacuum is causing the removal of energetically-unstable emitters and leading to the emission of single photons in a narrow wavelength range.

Abstract: Excitonic complexes such as neutral exciton, charged exciton, biexciton, and multiexciton in semiconducting transition metal dichalcogenides (TMDs) possess some exciting optical properties that are not present in conventional semiconductors. It has been observed that the localised excitons in some of these TMDs lead to the emission of single-photons. This offers new opportunities to construct scalable quantum architecture. Here, we investigate the effect of strain on neutral exciton and negatively-charged exciton in a bilayer tungsten diselenide (WSe₂). Using SiO₂ nanoparticles, we create strain in the WSe₂ bilayer to locally modify the bandgap, which leads to the funnelling of excitons, which in turn enhances the photoluminescence (PL) signal. We observe that two PL emission peaks, corresponding to direct and indirect excitons, are energetically separated in an unstrained region. Due to the presence of a dielectric nanoparticle which induces a huge strain up to 1%, we have observed a redshift and convergence of these peaks towards each other. These findings shed light on the optical properties and quantum behaviour of a 2D material, with potential applications in quantum technologies and optoelectronic devices, advancing our understanding of their unique properties for quantum optics.

Abstract: Two-dimensional (2D) materials beyond graphene have been recognized with a broad range of physical and chemical properties and utilized for various optoelectronic applications. Single photon emitters (SPEs) within transition metal dichalcogenides are emerging as intriguing quantum-light sources for future quantum photonics technology. In the past decade, strain engineering has remarkably evolved in deterministic positioning and creating the quantum emitters in TMDs. Here, we demonstrate the deterministic creation of SPEs in monolayer (ML) WS₂. When an ML WS₂ flake is deposited on top of the spin-coated silica nanoparticles (NPs) on a substrate, these NPs act as strain-introducers in the ML, producing the single photon emitters only at the NPs locations. To further tune the optical properties of these SPEs, we extend the height of NPs by depositing 50-100 nm of SiO₂ using an e-beam evaporation system. Spectroscopy and photon-correlation investigations on these single photon emitters will also be presented.

Abstract: Glutamate and glycine serve as important neurotransmitters in the brain. When an action potential travels through the terminal of a presynaptic neuron, it triggers the release of glutamate and glycine into the synapse through vesicles fusing with the cell membrane. These neurotransmitters then activate receptors on the cell membrane of the postsynaptic neuron. The entry of Ca²+ via activated NMDA receptors sets off a series of cellular processes, with long-term potentiation being particularly significant, as it is a key mechanism believed to underlie learning and memory. Analyzing how glutamate concentration is detected by postsynaptic neurons during Ca²+ signaling reveals that the average receptor density in hippocampal neurons has evolved to ensure precise measurement of glutamate concentration in the synaptic cleft.

Abstract: Lead-free metal halide perovskite has gained increasing attention in the past decade for photovoltaic and photoluminescent applications. Their stable and non-toxic nature, semiconductor-like behaviour with a tunable band gap, and improved optical absorption coupled with a relatively more straightforward synthesis technique have made them promising materials in this field. Magnetically they show unique helical ordering. We are to study the role of halides in this family of materials. Using the slow evaporation method, we have synthesized single crystals of two such metal halides, namely CsCuCl₃ and CsCuBr₃. Powder X-ray diffraction measurements and, thereupon, Rietveld analysis reveal the compounds to be non-isostructural with CsCuCl₃ crystallizing in hexagonal perovskite structure belonging to the P6122 space group, whereas CsCuBr₃ exhibits an orthorhombic structure belonging to the space group C2221. The UV-Vis DRS measurements show semi-conductor-like behaviour for both compounds. Further studies to investigate the ground state magnetic structure are ongoing.

Abstract: Two class of architectures is studied by use of Finite Element Analysis (FEA) here. By the use of interlocking architecture and honeycomb architecture it shown that mechanical properties can be tailored by use of different structures. The competing properties such as damping, and stiffness is simultaneously improved by use interlocking architecture. By hierarchal honeycomb architecture it is shown that by increasing hierarchy stiffness of the architecture is increased. Thus, by use these architecture stiffness and damping is tailored.

Abstract: Analysis of friction stir welded two aluminum alloys namely AA 6009 and AA 6101 were carried out. Hardness analysis of friction stir welded AA 6009 was performed. On the other hand, friction stir welded AA 6101 was subjected to preheating and further comparative analysis of tensile strength as well as residual stress of both preheated FSW samples and normal FSW samples were performed. Furthermore, Microscopical analysis of friction stir welded AA 6009 has been performed. Effect of preheating was clearly visible in the results obtained, with preheating resulting in reduction of tensile strength and enhancement of residual stresses of preheated FSW samples as compared to the tensile strength and residual stresses of normal FSW samples at different sets of weld parameters as considered. From the hardness point of view, enhancement of both tool rotational speed as well as weld traverse speed resulted in the improvement of hardness. Microscopical analysis revealed the existence of finer equiaxed grains in the stir zone and coarser grains in the thermo-mechanically affected zone along with the formation of onion rings in the stir zone.

Abstract: Aggregated nanoparticle structures are quite ubiquitous in aerosol and colloidal science, specifically in nanoparticle synthesis systems such as combustion processes where coagulation results in the formation of fractal-like structures. In addition to their size, morphology of the particles also plays a key role in defining various physicochemical properties. Electron microscopy based images are the most commonly used tools in visualizing these aggregates, and prediction of the 3-dimensional structures from the microscopic images is quite complex. Typically, 2-dimensional features from the images are compared to available structures in a database or regression equations are used to predict 3-dimensional morphological parameters including fractal dimension and preexponential factor. In this study, we propose a combination of evolutionary algorithm and forward tuning model to predict the best fit 3-dimensional structures of aggregates from their projection images. 2-dimensional features from a projection image are compared to the candidate projections generated using FracVAL code and optimized using Particle Swarm Optimization to obtain the 3-dimensional structure of the aggregate.

Abstract: The increasing global demand for clean and sustainable energy sources has led to significant advancements in energy storage and conversion technologies. The blending of fuel with nano-additives represents an innovative approach to revolutionize energy conversion processes, offering substantial improvements in efficiency and sustainability. The PSD of the dispersed nanoparticles significantly affects various physicochemical and transport properties of the nanofluids. Thus, the study focuses on the size distribution of the dispersed nanoparticles and the stability of the nanofuel suspensions prepared by the addition of Al2O3 (100 ppm) nano-additives to diesel fuel. The aggregation of dispersed nano-additives is hindered using Span80 surfactant to a certain extent, and the PSD of the dispersed nanoparticles is modified using mechanical methods, including ball milling and ultra-sonication. The emissions, combustion, and performance characteristics of the engine have improved with the use of 50-/100-ppm Al2O3 nano-additives. The ball-milled samples show better improvement in engine characteristics in contrast to the bath-sonicated samples. The physics behind the improvement in the combustion of nanofuel samples have been studied using the droplet combustion method, and the experimental results show the event of micro-explosion in the case of nanofuel samples, unlike diesel fuel.

Abstract: Composite materials have gained widespread use in engineering applications owing to their exceptional strength-to-weight ratio and tailored mechanical properties. However, the susceptibility of composites to damage from impact loading, especially at low velocities, poses a significant challenge to their reliable implementation. This study presents a comprehensive numerical investigation into the behavior of composite plates subjected to repeated low-velocity impacts using the finite element analysis software Abaqus. This research aims to elucidate the intricate damage mechanisms that emerge from repeated impacts on composite structures through a combination of material characterization, impact simulation, and damage assessment. The analysis involves the development of VUMAT subroutine for modelling nonlinearity and damage during transverse impact. The numerical simulations track the evolution of damage during multiple impact events, allowing for a detailed understanding of the cumulative effects of repeated impacts on the composite plate. Damage metrics such as delamination area, fiber breakage, matrix cracking, and changes in stiffness are monitored to assess the structural integrity and residual strength of the composite plate. Additionally, the simulation results are compared with experimental data to validate the accuracy and reliability of the numerical model. Insights gained from this study provide crucial information for designing composite structures capable of withstanding repeated impact loading. The numerical approach offers a cost-effective and efficient means of exploring a wide range of impact scenarios, enabling parametric studies investigating design parameters influence on the structural response. Ultimately, this research contributes to the advancement of composite material design, offering valuable guidance for engineering applications where repeated low-velocity impacts are a critical consideration.

Abstract: Air pollution stands as a prominent factor contributing to premature mortality. To gain valuable insights into ambient fine particulate matter (PM) concentrations in Asian countries, a combination of regulatory monitoring networks, satellite retrievals of air-quality-related substances, and air quality models is employed. These comprehensive studies consistently demonstrate that PM concentrations often exceed the guidelines set by the World Health Organization and the respective national ambient standards. However, it is crucial to recognize that numerous regions in Asia still need proper monitoring systems, hindering our understanding of their air quality conditions. The significant obstacle hindering progress in this area is the considerable cost associated with monitoring at various locations and on a regular basis. This research investigates the distribution and proportion of PM1, PM2.5, and PM10 inside the Indian Institute of Technology Goa campus. To enable continuous monitoring at a lower cost, we utilized cost-effective sensors such as PMS5003, PMS A003, PMS 7003, Winsen ZH 06, SPS 30, Novafitness SDS 011, and Honeywell. A comparative analysis was conducted to evaluate the performance of these sensors against the TSI DRX DustTrak 8533 and calibrated with a beta attenuation monitor (BAM) at Vikram Sarabhai Space Centre (VSSC) in Trivandrum, Kerala. Additionally, to enhance the accuracy and reliability of LCS measurements, the calibration through various regression and machine-learning techniques was explored under diverse environmental conditions. The factors such as reference bias, temporal drift, particle composition effect, sensor repeatability, and the influence of climate on sensor data within the characterization chamber were analyzed. In the absence of calibration techniques, the correlation coefficient (R 2 ) for PM 2.5 between the LCS and the DustTrak falls within a range of 0.62 to 0.73, indicating a moderate to strong relationship. However, when comparing the LCS with the BAM, the correlation decreases and ranges from 0.20 to 0.26, suggesting a weaker association. Further calibrating the sensors using regression and machine learning techniques with meteorological variables such as temperature, humidity, wind speed, and direction, the R 2 significantly improved. The R 2 using the DustTrak ranges from 0.82 to 0.96, and with the BAM, it varies from 0.40 to 0.56, and reducing the mean absolute errors and root mean square errors. The time-series results demonstrated typical seasonal patterns of winter highs and summer/monsoon lows. In this paper, we present air quality analysis for different locations in Goa using multiple measurement techniques.

Abstract: Biological cells are exposed to a variety of mechanical stimuli from their environment. Cells convert these mechanical stimuli to specific biochemical signals through a process known as mechanotransduction, which is necessary for proper functioning of cells. Biaxial stretching is one such stimuli observed in tissues such as lung alveoli, pericardium, blood vessels and urinary bladder. To study the effect of biaxial stretching on cell function, or any other mechanotransduction process, it is essential to develop tools capable of manipulating cells in the respective deformation mode. Here, we report the design, fabrication and actuation of a compliant micromechanism for in-plane, biaxial stretching of single cells. Our device is an amalgam of a gripper mechanism and an auxetic structure, which can be actuated using a mechanical probe. Cells can be stretched equibiaxially or with any non-equibiaxial stretch ratio, by altering the mechanism geometry. The device is made of SU-8 using a two-layer lithography process. Since SU-8 is transparent and biocompatible, we can attach cells to the device and image the cells during stretching. We show that our device is biocompatible by growing NIH 3T3 fibroblasts on it.

Abstract: Physical properties of cells such as the cell and nucleus shape have been shown to be important determinants of cell function and cell fate. Here, we develop a mechanical model for cell and nucleus shape. Our model consists of an inflated membrane compressed between a rigid flat plate and a stretched membrane. The inflated membrane is the nuclear envelope and the stretched membrane is the cell envelope and the rigid plate is the cell substrate. We show that the resulting cell and nucleus shapes are a function of four non-dimensional parameters. These parameters depend on the inflating pressure, elastic modulus of the nucleus envelope, tension in the cell envelope and the initial geometry of the nucleus before deformation. By changing these non-dimensional parameters we get different cell and nucleus shapes, which are characterized by their projected area (Ap), surface area (As) and volume (V). Since there are six geometric parameters, which are a function of four non-dimensional parameters, the model predicts a relationship among them. We verified this relationship on cell and nucleus shapes obtained using confocal imaging. Our work shows that cell and nucleus shapes can be represented by these four nondimensional parameters.

Abstract: The extensive utilization of gaseous and liquid fuels in energy production and transportation has led to severe environmental pollution and a substantial contribution to global warming and climate change. To mitigate these issues, a comprehensive understanding of combustion processes is imperative to minimize emissions from combustors. In this study, a numerical investigation of a bluff-body stabilized nonpremixed flame, serving as a representative flame for practical combustors, has been conducted. A tabulated chemistry model called Flamelet Progress Variable (FPV) approach, has been employed for modelling the combustion chemistry, integrated with Reynolds-Averaged Navier-Stokes (RANS) and Large Eddy Simulation (LES) modeling techniques, for modelling the turbulent flow. Computations are performed using the open-source flow solver OpenFOAM. The subgrid-scale stresses in the LES framework has been modelled by Smagorinsky and dynamic Smagorinsky models. The results from LES and RANS computations are compared with the measured values. The LES-FPV approach demonstrates favorable agreement with experimental data, particularly when utilizing the dynamic Smagorinsky model.

Abstract: This study addresses PM emissions from processes inherent in Indian cooking, which wield substantial influence over indoor air quality. Prioritizing both health and environmental impacts, we employed low-cost sensors to conduct a thorough assessment of PM concentrations and distribution in two distinct zones characterized by varying environmental conditions. To understand pollutant behaviour resulting from diverse cooking practices, and the influence of different ventilation systems on PM emissions, the study involved two distinct zones: Zone 1, furnished with specific ventilation sources, Chimney and two open interfaces, acting as shared entry points with Zone 2. Zone 2, a dining area, accommodates up to 300 people. The optimal seating area, which constitutes 53.33% of the total capacity, was chosen for analysis. Cooking times were logged, and surveyed for their oil usage during each activity. The factors influencing PM behaviour were identified, and their correlation analysis was performed. Moreover, we undertake a comprehensive assessment involving process and time based decay rates while evaluating location based bias in low cost sensors and reference monitors. Vertical profiling and air exchange rate parameters were also evaluated. By understanding the impact of cooking methods, ventilation, and other factors, this research cover major research gaps for indoor air pollution.

Abstract: Due to the ever-increasing application of composite materials in various engineering fields, it has become very essential to acquire detailed knowledge of their behavior under various loading scenarios and modeling using computational homogenization. To implement the FE2 approach, where the finite element method is used at both the micro and macro scale for evaluating the behavior of multi-phase materials, the computational procedure for the macroscopic tangent modulus has been presented in this paper. For this purpose, the condensation technique has been adopted due to its simplicity and easy implementation in comparison with other techniques. Subsequently, 2D representative volume elements (RVEs) are modeled with periodic boundary conditions (PBCs) for non-linear scenarios that are implemented in ABAQUS by a user-defined FORTRAN subroutine (UMAT) and a Python script. A comparative study demonstrates that the condensation process performs better in terms of saving computational time and storage requirements than the other approaches.

Abstract: Prediction of overall mechanical response of a composite laminate is essential in the design of composite structures. This can be achieved by using homogenized properties of the composite to perform a macro scale analysis of the composite structure. This poster provides a description of the Transformation Field Analysis (TFA) used to predict the overall response of elastic plastic composites and its implementation. The overall responses obtained from TFA are compared with those obtained from finite element analysis using a solver developed using Matlab. Parametric studies are then carried out to investigate the effect of different representative volume element (RVE) geometry, varying volume fraction, different loading, and varying plastic modulus on the overall response of the composites and the results are presented.

Abstract: The soot formation in a flame involves sequential processes of pyrolysis, nucleation, surface growth, and agglomeration. Based on the current understanding, soot can be reduced by inhibiting the nucleation process of soot precursors or by enhancing soot oxidation or fragmentation. The organometallic compound Ferrocene with the chemical formula (C5H5)2Fe has been reported to impact the soot generation mechanism. An experimental investigation was carried out to understand the sooty behavior of liquid fuels with the addition of organo-metallic compounds. The Ferrocene additive, with further structural changes made by adding OH and CHO functional groups, were added to n- heptane to understand, the temperature, Soot Volume fraction, emission data for the different samples considered. The experimental investigation with Two colour pyrometer, Laser Induced Incandescence (LII), Scanning Mobility Particle Sizer (SMPS) and portable aerosol monitor device was done. The Ferrocene samples had shown higher emission of PM 2.5 for lower mobility diameter of the particles emitted when compared with pure heptane sample, which points that there can be an enhancement of soot formation by the addition of Ferrocene to liquid fuels. Further study has to be performed to identify the constituents of the emission to get the detailed understanding.

Abstract: Magnesium/Teflon/Viton (MTV) pyrotechnic compositions are widely used in various applications. As magnesium has a high affinity towards atmospheric oxygen and moisture, this results in its oxidation, thus degrading its performance during storage. This study investigates the hygrothermal aging of an MTV pyrotechnic mixture. Thermogravimetry (TG) experiments are performed to obtain the kinetic parameters and to study the combustion reaction mechanism. Differential thermogravimetry (DTG) curves were analyzed to identify the mass loss steps occurring during the decomposition for both the pristine and aged samples. Scanning electron microscope-electron dispersive spectroscopy (SEM-EDS) revealed changes in morphology and chemical composition. The kinetic parameters were obtained through the Friedman isoconversional method. The aging mechanism is directly related to the safety, storage, and performance of MTV. It was observed that the influence of humidity causes significant changes in the TG curves and kinetic parameters. Also, unwanted compounds are formed as a result of aging, which causes a detrimental effect on performance.

Abstract: Fluid flow over porous media is a topic with great relevance in the scientific community because of the vast applications in biomedical engineering, flow over river beds, drag reduction, and increased heat transfer. In all these problems, knowledge of the transport phenomenon at the interface between the free fluid region and the porous media is crucial in capturing the physics. Presence of disparities in the length scale associated with channel (H) and pore (l) makes the problem multiscale and computationally expensive. The use of effective models based on multiscale homogenization has risen to overcome this hurdle due to its non-empirical nature. Most of these models are restricted to Stokes flow which is only sometimes the case in reality. A key modeling issue is to determine an accurate description of boundary conditions at the interface. In this work, we arrive at accurate interface conditions to capture weak inertia as well. We validate our model with a channel flow problem and compare it with a geometry-resolved simulation.

Abstract: Clathrate hydrate is a naturally occurring icelike solid that forms in the water phase under suitable temperature and pressure conditions in the presence of one or more hydrophobic molecules. It also forms inside the oil and gas pipes, leading to higher pumping cost, flow blockage, and even catastrophic accidents. Engineered surfaces with low hydrate adhesion can provide an effective solution to this problem. Liquid impregnated surfaces (LIS) are examples of engineered surfaces that have already shown tremendous potential for reducing the nucleation and adhesion of solids. Here, we report the design and synthesis of LIS with extremely low hydrate adhesion under an oil and water mixed environment. The most challenging aspect of designing these surfaces was to stabilize a lubricant layer simultaneously under water and oil. A detailed methodology to make such lubricant-stable surfaces from a theoretical perspective was described and experimentally validated for lubricant stability. Experimental measurements on such surfaces showed extremely low hydrate accumulation and one order of magnitude or more reduction in hydrate adhesion force.

Abstract: The primary objective of our research is to study the radiative effects of inhomo- geneity on the onset of convection using finite-volume approach. It is difficult to find the Critical Rayleigh number (the Rayleigh number at which the convection begins) for all ranges of optical thicknesses and concentration profiles (optical thickness, τ is the measure of photon mean free path and is the inverse of absorption coefficient). Hence we are developing an in-house numerical code that will solve the problem for a whole range of optical thicknesses. In order to validate the code we considered the standard test case of the Rayleigh-Benard convection, where convection and conduction determine the temperature profile. In this numerical setup, there is a radiatively non-participating medium placed between two parallel plates. The lower plate has a higher temperature, while the upper plate has a lower temperature, which we call the two-plate geometry. We present the validation results for standard benchmark cases such as the lid-driven cavity, RB convection in a square cavity, and the infinite plate configuration to establish the accuracy and reliability of our code implementation.

Abstract: The financial sector amplifies the risks of the real economy by being pro-cyclical in nature. When the economy heats up, there is a build-up of risks in the economy. These risks pose a huge threat because when there is an external shock which results in a downward fall in economic activity, the built-up risks exacerbate the process. This study analyses the build-up of financial risks in the Indian financial system - in terms of systemic risk, connectedness as well as risk spillover during different phases of financial and business cycles. Analysis of spillover is done using a time-varying parameter vector autoregression (TVP-VAR) model and the results are compared with financial and business cycles using correlation analysis. This is one of the first attempts to study how financial risk behaves during different phases of economic cycles in India. The results suggest that systemic risk is positively correlated with credit cycles and systemic risk is a lagging indicator for both credit cycle and IIP cycles.

Abstract: Antifragility is the property of an entity or system that not only withstand shocks, randomness, and volatility but actually benefits and improves from them. In essence, antifragile systems thrive in the face of uncertainty and chaos, becoming stronger and more resilient as they encounter challenges. Antifragility can be observed in the economy through events such as business cycles i.e. the periodic expansion and contractions experienced by an economy in its long run growth. A business cycle allows us to observe antifragility in the economy at both individual and collective levels. Various components of the economy - at the sector level and even granular level of firms adapt during a business cycle making the economy stronger for the consecutive boom. We explore the possibility of antifragility at work in business cycles through agent based modelling and complexity economics.

Abstract: Sarwaria Bhojpuri is a sub-dialect of the Bihari language family. It is spoken in the Basti and Sant Kabir Nagar districts of Uttar Pradesh. It has been referred to as a dialect of Northern Standard Bhojpuri in the Linguistic Survey of India, which George Grierson conducted. This paper aims to preserve and document the agricultural lexicons of Sarwaria Bhojpuri on a digital platform. Lexicographers have done archiving and documenting lexicons. Traditional lexicographers were not able to register the actual sound of the speaker in a dictionary. Using the FLEx software, researchers can add the natural speech sound of the speech community for the lexicons. Lexicon is referred to as the mental representation of words. As native speakers of a language, we acquire the language subconsciously. If we know a word, we not only know the meaning of the word, but we acquire the phonology, morphology, semantics, syntactic, and pragmatic aspects of lexicons. A word does not occur as a socially divorced unit. It carries social meaning. A word reflects identity, culture and history. Words are a reflection of a speech society, how a speech community categorises and classifies things and phenomena which occur around them. For example, the Sarwaria Bhojpuri speech community is predominantly an agricultural-based society, and there are so many lexicons which are related to the agricultural sphere of the speech community../ɖʰekur/ and/hɑːt̪ʰɑː/ were used for irrigation tools.

Abstract: Ferrocene is a well-known organometallic compound that exhibits intramolecular charge transfer. Ferrocene shows two prominent bands cantered at 326 nm and 330 nm, respectively, assigned to 𝜋−𝜋∗ and MLCT transitions. The substituted Ferrocene derivatives have been reported to exhibit second-order nonlinear optical properties. The non-linear optical properties are known to be affected by charge transfer processes. The functionalization of Ferrocene can manipulate ET in Ferrocene to create charge-separated states. We have investigated various 𝛼, 𝛽 unsaturated keto-substituted Ferrocene using steady-state and time-resolved absorption spectroscopy. We observe noticeable differences in excited state dynamics among ferrocene derivatives. Compared to their phenyl counterparts, an enhanced stabilization of the charge-separated state in the pyridyl derivative is observed. Additional stabilization was achieved with the addition of the halogen on the substituents. These compounds exhibit second-order nonlinear properties.

Abstract: Developing P^N and P^C classes of ligands and studying their catalytic properties is an emerging and attractive research field.1 Appropriate tuning of ligand electronic and steric properties can control the selectivity for the desired product and enhance the catalytic activity.2 ^N⁄_C donor sites of a ^PN ⁄ _P^C ligand allow different bite angles and electronic environments around the metal center in contrast to the traditional P^P ligands. It was evident from the literature that the Ad2P-(Ad = adamantyl) provides better stability of the catalytic system due to the steric bulk of the adamantyl groups.3 Keeping the Ad2P- framework intact, we varied the other donor site (N or C) on the aryl group attached to Ad2PAr. Synthesis, characterization, and X-ray crystal structure of P^N & P^C ligands and the corresponding Pd complexes showed a promising new class of ligand systems. P^N ligand forms a neutral monomeric Pd complex, whereas the P^C ligand forms a negatively charged compound monomeric complex. The catalytic activity of the synthesized complexes was studied in the C-N bond-forming reactions.

Abstract: The sensing activity of bis(indolyl)methane (BIM) could be exploited by the selective functionalization of the molecules. It is interesting to notice that these molecules have shown to be active sensors for anions as well as cations under similar conditions and exhibit similar spectral features in both cases. The distinct color change could be attributed to the formation of oxidized products with extended conjugation. An investigation with BIM derivatives (BIMs) has been done through Femtosecond transient absorption and quantum chemical calculations to study the dynamics of BIM derivatives as precursors in developing novel molecules. It has been observed that the acidic medium plays a vital role in governing the spectral characteristics of BIMs, imputing to the ambivalent nature of BIMs in acidic conditions. This work has intended to resolve the conflicting reports that have been attributed to BIM molecules acting as sensors for cations as well as anions. We infer that the propensity to lose the meso-hydrogen is enhanced under acidic conditions. Although the functionalization with electron-withdrawing or electron-donating groups seems to affect photophysical properties such as spectral shift, quantum yield, etc. tuning the acidity medium plays a significant role

Abstract: On compression, supercooled water transforms into glass at very high pressure, characterized by a rapid convergence to zero diffusion limit in absence of crystalline order. Although the whole system remains in the liquid phase until the pressure is very high, the local structure of supercooled water gradually changes upon increasing pressure. Here, we have studied the local structural changes of the supercooled TIP4P/ICE water model by varying the pressure from 1kbar to 150kbar. We find that, at low pressure, it resembles IceIh (the most stable ice polymorph at this state point) like structure with four hydrogen bonded water molecules within the 1st neighbor shell forming tetrahedral geometry. Upon increasing pressure, it changes in accordance with the local structure of the most stable polymorph at a given pressure. Thus, we find a gradual change in the order of iceIh -->IceIII --> IceV upon increasing pressure. This indicates that the local structure of supercooled water is guided by the basin of attraction of the most stable ice polymorph at a given state point. We also observed the disappearance of shell-like structure of a central water molecule upon increasing pressure to intermediate level and then its reappearance at high pressure.

Abstract: Previously in our lab, we synthesized a compound collection based on a bridged pyrrolidine scaffold (vide infra), represented below. Interestingly, they showed excellent antibiotic activity against the S. aureus strain of bacteria. With this background, we hypothesized if there is a possibility to simplify the scaffold of our hit compound and if that will retain the activity of the parent compound. Towards that, we decided to break the C-C bond at the C-2 position of the indole, which provides the tetrahydro pyrrolidine as the simplified scaffold to explore the potential antibiotic activity against S. aureus (Scheme 1). Scheme 1: Retrosynthetic scheme for simplifying bridged pyrrolidine scaffold to obtain L-Tryptophan tetrahydro pyrrolidine derivatives. As shown in the scheme above, synthesizing the original hit takes much work. We decided to break the C-C bond at the 2-position of the indole to obtain a tetrahydro pyrrolidine scaffold. The tetrahydro pyrrolidine derivatives can be readily synthesized by a 1, 3- dipolar cycloaddition reaction between nitrostyrene derivatives and α-imino esters of L-Tryptophan in good yields. A highly efficient Ag(I)-catalyzed [3+2] cycloaddition reaction between 1,3-fused cyclic azomethine ylide and nitroalkene has been developed to synthesize functionalized tropane scaffolds with quaternary and tertiary stereocenters.

Abstract: Since the beginning of chemistry, heterocycles have been among the most important types of compounds in day to day life. Among heterocycles, highly arylated furans are privileged motifs with numerous applications in the material sciences and pharmaceuticals. Because the physical properties of polyarylated furans are determined by the nature of the peripheral aryl groups, approaches to tetra-aryl substituted furans with diverse peripheral groups are in high demand. Herein, we report the efficient synthesis of diversely functionalized furans with up to four different (hetero)aryl groups via base metal mediated successive cross-dehydrogenative coupling. This represents the first example of the synthesis of bisindolyl furans containing two non-identical indoles. The resulting furans were functionalized into interesting derivatives. The use of earth-abundant metals, such as copper and iron, and a step-economic approach make this one-pot synthesis highly desirable for accessing high-valued and complex tetra-arylated furan scaffolds.

Abstract: A heterocyclic compound containing an indole atom exhibit biological activity and it has a high affinity to bind with most biological target. The indole ring is believed to be one of the most desirable scaffolds in medicinal chemistry. The indole-heteroaryl methane class of compounds has significant potential as a pharmacological substance. They have reportedly demonstrated a wide variety of bioactivity, including anticancer, anti-inflammatory, and antibacterial activities. Here, we have developed a method to synthesize indolylfuryl methane molecules (Bis heterocyclic scaffolds) which employs a DMSO solvent to insert a methylene group between two distinct heterocycles indoles and furans. In this methodology, DMSO has a dual role, it serves as a source of methylene group as well as a solvent and acetyl chloride as an activator. Expected bis-heterocyclic compounds were isolated in good to high yields. Our approach offers metal free condition, low cost effective, easily accessible starting material, using less toxic solvent and a milder reaction condition.

Abstract: Pyrroles, are the most well-known five-membered nitrogen-containing heterocyclic compounds. It is a crucial structural element that serves as the foundation for several biologically significant natural products, including heme, chlorophyll, and vitamin B12. Atorvastatin (Anti-hyperlipidemic) is one of the best-selling drug in the market till today containing a pyrrole motif. The construction of pyrrole rings has received considerable attention in the last few decades because of its unique biological activity, its pharmaceutical uses, and as an intermediate in the synthesis of many natural products, as well as its applications in materials science. Our strategy involves the use of 1-Azapenta-1,3-diene-5-ols (b), easily accessible from 1-Azapenta-1,3-diene-5-ones (a) and Phenyl-lithium compounds (in-situ generated) for the synthesis of Pyrrole. Treatment of 1-Azapenta-1,3-diene-5-ols (b) with a mild acid (Lewis acid), BiCl3 leads to the formation of 1-Azapentadienyl cation intermediate (c). The intermediate cation (c) then undergoes facile 4π-electrocyclization followed by 1,2-Wagner Meerwein shift under the ambient condition to give diversely substituted pyrroles in moderate to good yield. Differential reactivity was also observed, like the formation of trisubstituted pyrrole, tetrasubstituted pyrroles, and indenes when b was slightly modified and BiCl3 loading. Characterization of all the newly synthesized molecules was done with NMR spectroscopy.