Showing papers by "Indian Institute of Technology Bhubaneswar published in 2022"

Principal component analysis technique for early fault detection

Abstract: Online condition monitoring and predictive maintenance are crucial for the safe operation of equipments. This paper highlights an unsupervised statistical algorithm based on principal component analysis (PCA) for the predictive maintenance of industrial induced draft (ID) fan. The high vibration issues in ID fans cause the failure of the impellers and, sometimes, the complete breakdown of the fan-motor system. The condition monitoring system of the equipment should be reliable and avoid such a sudden breakdown or faults in the equipment. The proposed technique predicts the fault of the ID fan-motor system, being applicable for other rotating industrial equipment, and also for which the failure data, or historical data, is not available. The major problem in the industry is the monitoring of each and every machinery individually. To avoid this problem, three identical ID fans are monitored together using the proposed technique. This helps in the prediction of the faulty part and also the time left for the complete breakdown of the fan-motor system. This helps in forecasting the maintenance schedule for the equipment before breakdown. From the results, it is observed that the PCA-based technique is a good fit for early fault detection and getting alarmed under fault condition as compared with the conventional methods, including signal trend and fast Fourier transform (FFT) analysis.

Dynamics of Clogging in Subsurface Flow Constructed Wetlands

Abstract: Subsurface flow constructed wetlands (SSF CWs) are increasingly used globally for the removal of pollutants from wastewater. However, clogging of the filter bed is the main operational and...

A Fast and Adaptive Dynamic Phasor Estimation Algorithm Implemented on Field Programmable Gate Array (FPGA)

Abstract: A fast and precise dynamic phasor estimation algorithm using an adaptive improved second order Levenberg–Marquadt algorithm under stressed and off-nominal frequency circumstances is proposed in this paper The proposed algorithm ventures a faster quasi-second-order method and in addition, the learning rate is also made adaptive to speed up the convergence Moreover, the projected estimator essentially filters harmonics, estimates transients in a signal during faults and effectually performs in complex modulated setting which is found commonly in a power system with distributed energy resources Outcomes reveal that the estimation errors and the convergence time of the proposed approach is way below the minimum requirement of the IEEE C371181 standard Besides, due to its reduced complexity, the estimator has been successfully implemented on the field programmable gate array (FPGA) platform and has been verified on a practical microgrid scenario including photo voltaic systems The performance during testing indicates that the proposed technique has potential ability to perform under stressed conditions conforming the accuracy and speed of response

Operator valued analogues of multidimensional Bohr’s inequality

Abstract: Abstract Let $\mathcal {B}(\mathcal {H})$ be the algebra of all bounded linear operators on a complex Hilbert space $\mathcal {H}$ . In this paper, we first establish several sharp improved and refined versions of the Bohr’s inequality for the functions in the class $H^{\infty }(\mathbb {D},\mathcal {B}(\mathcal {H}))$ of bounded analytic functions from the unit disk $\mathbb {D}:=\{z \in \mathbb {C}:|z|<1\}$ into $\mathcal {B}(\mathcal {H})$ . For the complete circular domain $Q \subset \mathbb {C}^{n}$ , we prove the multidimensional analogues of the operator valued Bohr-type inequality which can be viewed as a special case of the result by G. Popescu [Adv. Math. 347 (2019), 1002–1053] for free holomorphic functions on polyballs. Finally, we establish the multidimensional analogues of several improved Bohr’s inequalities for operator valued functions in Q .

An open-source implementation of a phase-field model for brittle fracture using Gridap in Julia

Abstract: This article proposes an open-source implementation of a phase-field model for brittle fracture using a recently developed finite-element toolbox, Gridap in Julia. This work exploits the advantages of both the phase-field model and Gridap toolbox for simulating fracture in brittle materials. On one hand, the use of the phase-field model, which is a continuum approach and uses a diffuse representation of sharp cracks, enables the proposed implementation to overcome such well-known drawbacks of the discrete approach for predicting complex crack paths as the need for re-meshing, enrichment of finite-element shape functions, and an explicit tracking of the crack surfaces. On the other hand, the use of Gridap makes the proposed implementation very compact and user-friendly that requires low memory usage, and provides a high degree of flexibility to the users in defining weak forms of partial differential equations. Tests on a single-edge notched plate under tension, an L-shaped panel, a notched plate with a hole, a notched beam under symmetric three-point bending and a notched beam with three holes under asymmetric three-point bending are considered to demonstrate how the proposed Gridap-based phase-field Julia code can be used to simulate fracture in brittle materials.

Multipoint monitoring of amplitude, frequency, and phase of vibrations using concatenated modal interferometers

Abstract: Concatenated modal interferometers-based multipoint monitoring system for detection of amplitude, frequency, and phase of mechanical vibrations is proposed and demonstrated. The sensor probes are fabricated using identical photonic crystal fiber (PCF) sections and integrated along a single fiber channel to act as a compact and efficient sensing system. Each identical probe acts as a modal interferometer to generate a stable interference spectrum over the source spectrum. In the presence of an external dynamic field about each probe, the probes respond independently, producing a resultant signal superposition of each interferometer response signal. By analyzing the resultant signals using computational techniques, the vibration parameters applied to each interferometer are realized. The sensing system has an operation range of 1 Hz-1 kHz with a sensitivity of 51.5 pm/V. Such a sensing system would find wide applications at industrial, infrastructural, and medical fronts for monitoring various dynamic physical phenomena.

Impact Analysis of Thin-Walled Cylindrical Tubes

Abstract: In this study, the energy dissipation as well as crash-worthiness of thin-walled tubes of different cross-sections after the addition of face plates, both, with and without foam cases under dynamic impact conditions are investigated through numerical simulations. The finite element code ABAQUS/Explicit is employed to carry out the simulations. Cylindrical tubes of different geometries, such as circle, ellipse, hexagon, square, and triangle, assigned by aluminum properties are considered for the impact analysis. The analysis is performed on four different configurations of the thin-walled tubes: (i) cylindrical tube alone, (ii) tube with face plate, (iii) tube with foam, (iv) tube with face and foam. The nonlinear distortion properties obtained through axial compression loading are used in the simulations. The addition of face plates to the thin-walled tubes alters the deformation modes as well as the folding pattern compared to the tube configurations without face, both, with and without foam addition. The outcomes after employing the face plates to the hexagonal thin-walled tube are observed to be exhibiting the least deviation in specific energy dissipation, as compared to the respective tube configurations without face plates.

Effects of Pharmaceuticals on the Performance of Earthen Pot Microbial Fuel Cell

Abstract: A study was conducted to introduce an efficient alternative such as bioelectrochemical degradation of pharmaceuticals. Six earthen pot MFCs were operated in batch mode, in which the pharma...

Effect of humidity on the performance of rooftop solar chimney

Abstract: A mathematical model of a solar chimney was developed considering moist air as a participatory media. This model coheres to the steady-state heat transfer equations derived for glass cover, moist-air between the glass cover and the absorber wall, and for the absorber wall separately. An in-house developed MATLAB code solves the equations via matrix method, utilizing the Gauss–Seidel iteration technique. A study was done on dry as well as moist air that flows between the glass and absorber plate of the solar chimney. Air absorbing heat by mode of convection, radiation, and both was considered. Performance of the system is characterized in terms of the mass flow rate of air. Variation of mass flow rate of air with the gap between the glass and the absorber plate is studied as a function of relative humidity. The effect of ambient temperature and radiation on solar chimney’s performance was reported. The result shows an improvement of 10% in the performance of solar chimney driven by moist air as compared to dry air at 45°inclination of chimney. Chimney inclination of 45°was found to be optimum for Bhubaneswar (India), as it has higher mass flow rate compared to other inclination for most duration. It is also concluded that the mass-flow rate through the solar chimney directly depends on the gap between absorber plate and glass cover. Compared to 0.1 m air gap, there is about 62% and 114% increase in mass flow for the gap of 0.2 m and 0.3 m, respectively.

Contact geometry and quantum thermodynamics of nanoscale steady states

Abstract: We develop a geometric formalism suited for describing the quantum thermodynamics of a certain class of nanoscale systems (whose density matrix is expressible in the McLennan–Zubarev form) at any arbitrary non-equilibrium steady state. It is shown that the non-equilibrium steady states are points on control parameter spaces which are in a sense generated by the steady state Massieu–Planck function. By suitably altering the system’s boundary conditions, it is possible to take the system from one steady state to another. We provide a contact Hamiltonian description of such transformations and show that moving along the geodesics of the friction tensor results in a minimum increase of the free entropy along the transformation. The control parameter space is shown to be equipped with a natural Riemannian metric that is compatible with the contact structure of the quantum thermodynamic phase space which when expressed in a local coordinate chart, coincides with the Schlogl metric. Finally, we show that this metric is conformally related to other thermodynamic Hessian metrics which might be written on control parameter spaces. This provides various alternate ways of computing the Schlogl metric which is known to be equivalent to the Fisher information matrix.

Role of meteorology in atmospheric aerosols and air pollution over South Asia

Abstract: The South Asian region and its urban centers rank among the most polluted in the world attributed to the anthropogenic emissions that have grown over the years. It is widely known that meteorological parameters play a substantial role in pollutant dispersion within the atmosphere on various time and spatial scales. In this chapter, the air pollution with a focus on particulate matter and its dependence on prevailing meteorology is discussed. The nature of surface winds largely explains the particulate matter pollution over the Indo-Gangetic Plain (IGP) over South Asia. However, their effect on the overall aerosol loading is found to be seasonally contrasting in nature. For example, wind anomalies that strengthen (weaken) prevailing westerly winds during premonsoon (monsoon) season lower (enhances) aerosol loading due to strengthened dispersion (long-range transport). On the contrary, a weakening of wind leads to stagnation (weakened long-range transport) and hence enhanced (suppressed) aerosol loading during winter (postmonsoon). Such information is important while making policy decisions to mitigate air pollution.

Runoff Prediction Using Hybrid SVM-PSO Approach

Abstract: Prediction of runoff is vital for water planning and management, design of canals, estimating soil erosion and flood control. This study aims at employing support vector machine (SVM) in combination with particle swarm optimisation (PSO) algorithm for runoff prediction at Nayagarh watershed, India. Prediction accuracy of SVM largely depends upon parameter selection. So here PSO is used for finding optimal SVM parameters. Three statistical indices Nash–Sutcliffe coefficient (ENS), Mean absolute error (MAE), Coefficient of determination (R2) are considered for testing performance of proposed hybrid model. The results indicate that use of PSO optimisation algorithm extremely improved overall performance of SVM model. Also it was concluded that SVM-PSO could be a better alternative to predict runoff as it gives a higher degree of accurateness and consistency.

Advances in Bioremediation of Extremely Alkaline Bauxite Residue: A Review

Abstract: Bioremediation of alkaline materials using alkaliphilic and other varieties of microorganisms is one of its own kinds of ecofriendly, sustainable, cost- and energy-efficient, clean and green technology. Until recently, the extremely alkaline bauxite residue (pH > 11) was treated using various physio-chemical techniques to render it suitable for utilization. However, the present study discusses possible bioremediation techniques to reduce the exorbitant pH and sustain it for a practical duration. It is observed here that there are microbial species, which can proliferate in such extreme chemico-minerological conditions. This study reviews various bioremediation technologies which have been successfully employed by previous studies on soils and wastes. Microbial species identification and their working mechanisms that have the potential to treat alkaline wastes and soils are discussed. This review is an attempt at introducing new avenues and prospects for research into the field of amendment and utilization of bauxite residue. To increase the utilization of bauxite residue, microbial enzyme might constitute a novel technique for waste management.

Seasonality in long-term trends of tropical intraseasonal wave activity

Abstract: Long-term trends in the intensity of tropical intraseasonal oscillations, like Madden and Julian oscillations (MJO), tropical depressions and convectively coupled equatorial waves namely Kelvin, Rossby and mixed Rossby–gravity (MRG) waves along with tropical depressions (TD) are presented for the period of 40 years from 1979 to 2018. Daily data of satellite-observed outgoing longwave radiation is used to quantify these waves. From the spatial distribution of waves during different seasons, it is seen that there is large heterogeneity of trends in space and time. Most of the waves are observed to have over all increasing trends in boreal winter (December, January and February, DJF) season, in particular over the Northern Hemisphere. Kelvin wave shows the most homogeneous behavior with significant increasing trends throughout the tropics in this season. In case of MJO, over the period in consideration, spatio-temporal distribution of intensity tends to become more homogeneous with regions of climatological peak having decreasing trends and vice versa. Spatially, MJO and Rossby waves have decreasing intensities, whereas Kelvin and MRG-TD have increasing intensities in almost all the seasons over the Central Pacific. Comparison with long-term trends in sea surface temperature (SST), vertical shear of zonal wind and total column water vapor (TCWV) show that SST and TCWV explain observed trends in waves only in limited cases, since these decrease over a longer period of time over Central Pacific. However vertical shear shows more significant influence on wave tendencies and seems to be a greater contributing factor in long-term variations of waves.

Quantum information scrambling and quantum chaos in little string theory

Abstract: A bstract In the current manuscript we perform a systematic investigation about the effects of nonlocal interaction to the spread of quantum information in many body system. In particular, we have studied how nonlocality influence the existing bound on the growth rate of the commutator involving two local operators, the butterfly velocity. For this purpose, we consider the nonlocal theory on the worldvolume of N ≫ 1, NS5 branes arising in the limit of vanishing string coupling, the ‘little string theory’. A direct evidence of nonlocality can be realized from the ‘volume law’ behavior for the most dominant part of holographic entanglement entropy. We obtain the butterfly velocity by studying the dynamics of the near horizon geometry backreacted by a high energy quanta in the form of a shockwave resulting from an early perturbation on the corresponding thermofield double state. We observe that the butterfly velocity increases with the nonlocal scale of little string theory, the inverse Hagedorn temperature β h , indicating a faster rate of information spread due to the nonlocal interaction. The same conclusion follows as the disruption of two sided mutual information is observed to occur at a faster rate for higher values of β h . Finally, we realize a direct connection between the parameters of quantum chaos and the quasinormal modes for collective excitations through the phenomenon of ‘pole skipping’.

Removal of Lignin from Wastewater Using an Industrial Waste as Adsorbent: A Statistical and Kinetic Modeling Approach

Abstract: Lignin and its derivatives are identified as the prime pollutants in the effluents of many industries such as rice mill, paper, and pulp, which subsequently create dark coloration and toxi...

Identification of Selection Signatures for Milk Performance Traits among Indigenous Dairy Cattle Breeds using High Density Genomic Information

Abstract: Background: Selection process for milk performance traits has left remarkable selection signatures in the genome and their identification can guide to utilize under genomic breeding programs for improving productivity in dairy cattle. Methods: This study utilizes genotype data of Sahiwal (19), Tharparkar (17) and Gir (16) to identify selection signatures in the genomes of Sahiwal-Gir (SW-GR), Sahiwal-Tharparkar (SW-TP) and Tharparkar-Gir (TP-GR) breed pairs by using FST approaches. The highest FST peaks (FST greater than 0.25) were considered as selection signature region. The functional genes underlying signature regions controlling milk performance traits were also annotated. Result: We identified 41, 29 and 60 selection signatures exhibiting footprints of positive selection among SW-GR, SW-TP and TP-GR breed pairs, respectively. The selection signals controlling milk performance traits were detected as ACADL, SLC26A2, PLCB1, SYT9 genes mapped on chromosome 2, 7, 13 and 15, respectively for SW-GR breed pair. Selection signature regions in the genome of SW-TP breed revealed genes ATPAF1, LEF1, PPARGC1B, EIF6 and ACSS3 for milk production. Furthermore, PLA2R1, SCP2, ATPAF1, CACNA2D1, LEF1 and SUMF1 genes were identified in TP-GR breed pair controlling metabolism and morphogenesis of mammary gland. Moreover, HSPB6, LTBP1, SLIT3, FSHR and ASIP genes were also found in association with thermo-tolerance, disease resistance, immunity, reproduction and coat colour in our indigenous dairy cattle breeds.

Conjugate Heat Transfer Analysis in a Composite Building Wall: Effect of Double Plaster-Brick-Glass Wool

Abstract: The goal of this analysis is to explore heat transmission by three modes of heat transfer in a double plaster-brick-glass wool wall with a layer of air between them. The governing equations were solved using SIMPLE scheme of finite volume method (FVM). Effects of solar radiation (up to 1000 W/m2), variation of glass wool thickness (2–5 cm), and variation of thermal emissivity (0.1–0.9) on the heat transfer through the composite wall were examined. It was found that the surface radiation has contributed more than 60%, while the natural convection and conduction were not exceeding 23.08% and 3.39%, respectively, in the heat transfer process. The effect of variation in glass wool thickness was insignificant on the coefficient of overall heat transfer, but the inside wall temperature reduced by 0.25%. The mean temperature of the inner wall surface was reduced to 10.8%. The low emissivity structure surfaces (Ɛ < 0.3) offered strong thermal resistance in heat transfer. The results suggested that a 2 cm layer of glass wool insulation and low emissivity surface can significantly reduce the building energy usage.

Rheological properties of bauxite residue: the role of tailings gradation and solids concentration

Abstract: Debris flow ensued as a result of tailings dam failure depends greatly on the fluidity of slurry created and is better described by measuring the rheological properties. In the present study, rheological properties (i.e. viscosity and yield stress) of bauxite residue are measured using dynamic shear rheometer with parallel plate configuration to understand the role of tailings gradation, solids concentration, and moisture content. Rheology measurements are taken on three variety of tailings gradations (coarse: 0.15 mm), and fine: < 0.075 mm) by varying solids concentration from 67.57 to 72.46% and moisture content from 38 to 48%. Additionally, stress growth tests with resting time are performed to determine the static yield stress, the measurement of which is important to get insight into debris flow initiation. Herschel–Bulkley model is used to infer the information of viscosity and yield stress parameters. The viscosity is measured as 2033 Pa-s and 930 Pa-s with shear rate of 0.1 s−1 at 38 and 48% moisture content, respectively. It is found that static yield stress is 15–20 times higher than the dynamic yield stress for bauxite residue, attributed to thixotropy behaviour. Besides measurements by rheometer, yield stress is also measured by slump tests using cylindrical mould set-up. It is noticed that bauxite tailings prevalently show non-Newtonian fluid characteristics and shear-thinning behaviour at different solids concentrations. The results are vital to assess the impacted area, run-out length, front velocity, distribution, and pumping energy of tailings if released instantaneously in colossal amount.