National Institute of Technology, Jamshedpur
Recent publications
We investigate through this research the numerical inversion technique for the Laplace transforms cooperated by the integration Boubaker polynomials operational matrix. The efficiency of the presented approach is demonstrated by solving some differential equations. Also, this technique is combined with the standard Laplace Homotopy Perturbation Method. The numerical results highlight that there is a very good agreement between the estimated solutions with exact solutions.
Locally available expansive clays (bentonites) are planned to be used as buffer material in deep geological repositories. The current study highlighted the significance of various geotechnical properties such as specific gravity, liquid limit, plastic limit, specific surface area, cation exchange capacity, percentage of clay content, smectite content and dry density on the swelling pressure of the compacted expansive clays using soft computing techniques such as multiple linear regression (MLR) and artificial neural network (ANN). In total, 185 experimental results of 14 different expansive clays of 27 batches were considered from literature. The investigation was carried out by 2 computational approaches. Initially, MLR technique was used and the swelling pressure was assumed to vary linearly with clay properties. In the second approach, nonlinearity was included using ANN technique. Levenberg–Marquardt (LM) and Scaled Conjugate Gradient (SCG) algorithms were used in ANN approach. The sensitivity analysis of the soil properties was carried out and the parameters were ranked according to their influence on the development of swelling pressure. The nonlinear method was found to be more accurate than the linear method. The LM algorithm was noted to be more accurate in predicting swelling pressure of compacted expansive soil than that of SCG. Among all the influential parameters, the dry density was found to be the most critical parameter to predict the swelling pressure of compacted expansive clays. The outcome of current study models can be useful to predict swelling pressure of compacted bentonite that would be helpful to select buffer material in deep geological repositories.
This study presents a novel improved differential evolutionary (IDE) algorithm for optimizing reactive power management (RPM) problems. The effectiveness of IDE algorithm is tested on different unimodal and multimodal benchmark functions. The objective function of the RPM is considered as the minimization of active power losses. Initially, the power flow analysis approach is employed to detect the optimal position of flexible AC transmission system (FACTS) devices. The proposed method is used to determine the optimal value of control variables such as generator's reactive power generation, transformer tap settings, and reactive power sources. Furthermore, the efficacy of the IDE approach is compared with other promising optimization methods such as variants of differential evolution algorithm, moth flame optimization (MFO), brainstorm‐based optimization algorithm (BSOA), and particle swarm optimization (PSO) on various IEEE standard test bus (i.e., IEEE‐30, ‐57, ‐118, and ‐300) systems with active and reactive loading incorporating FACTS devices. A Static VAR compensator (SVC) for shunt compensation and a thyristor‐controlled series compensator (TCSC) for series compensation were used as FACTS devices. The proposed IDE method significantly reduces the active power loss, that is, 55.65% in IEEE 30, 39.68% in IEEE 57, 16.32% in IEEE 118, and 8.56% in IEEE 300 bus system at nominal loading. Finally, the statistical analysis such as Wilcoxon signed‐rank test (WSRT) and ANOVA test were thoroughly analysed to demonstrate the firmness and accuracy of the proposed technique.
This paper deals specifically with the active MASW method, which was applied for subsurface exploration of a region in Jamshedpur city, India, to study the various lithological and stiffness properties of subsurface materials. The study investigates the impact of data acquisition parameters on obtaining a high-resolution dispersion image, based on the ongoing MASW survey. A linear array of 24 numbers of 4.5 Hz geophones was used to collect raw wavefield traces generated by a 10 kg sledgehammer. Wavefields were regulated using a range of sampling frequencies (500 Hz, 1000 Hz, 2000 Hz, 4000 Hz, and 8000 Hz), as well as offset distances (1, 2 m, 4 m, 6 m, 8 m, 10 m, and 12 m) and inter receiver spacing (1 m and 2 m). Based on the results, the best data collection parameters for a high signal-to-noise ratio were determined to be: 1000 Hz sampling frequency, 8 m offset distance, and 1 m inter receiver spacing, resulting in a sufficient resolution dispersion image. Moreover, 1D and 2D shear-wave velocity profiles for the chosen site were derived. The stiff silty clay soil (up to a depth of 5 m) and dense to very dense weathered mica schist was found (at variable locations and depths from 8 to 30 m or beyond). The average Vs30 is 402 m/s, and the site is classed as Type C as per NEHRP Site Classification. The shear-wave velocity profiles show a high level of agreement with borehole data, demonstrating the effectiveness of the non-invasive technology for sub-surface investigation.
The designing and development of wideband polarization insensitive Metamaterial Microwave Absorber (MMA) is presented in this paper. The proposed unit cell consists of four trapezoidal which is connected to concentric square and cantered square via lumped resistors. The absorber is designed on FR-4 substrate with permittivity 4.3 and thickness 0.256 mm (λ/144). The wideband absorptivity with more than 90 % absorption is obtained from 2.21 GHz to 6.61 GHz having bandwidth of 4.40 GHz. Two distinct absorptivity peaks have been perceived in the range of interest having frequencies at 2.49 GHz and 5.68 GHz with maximum magnitude of 92.50% and 92.14%. The designed absorber is also found to be polarisation insensitive for both TE and TM polarised Electromagnetic (EM) wave up to oblique incidence of about 60°. These two peaks arise because of plasmonic resonance. The fabricated structure is measured inside the Anechoic Chamber, the simulated and measured results are almost similar to each. The proposed absorber structure finds applications for S (2-4 GHz) and C (4-8 GHz) band particularly in defence applications for wideband stealth applications and RCS reductions.
An increasing amount of electronic waste (e-waste) is not a new concern. It has been causing trouble globally. This waste comprises valuable metals and harmful compounds that lead to detrimental environmental conditions. Managing this kind of waste in developing economies is difficult due to different barriers hindering the process. Therefore, the goal of this research work is to determine the barriers while taking expert opinions and through available literature, and subsequently prioritize them to address the challenges in e-waste management. Moreover, this study utilizes an integrated Fuzzy Decision-Making Trail and Evaluation Laboratory (F-DEMATEL) and Fuzzy Interpretive Structural Modeling (F-ISM) approaches to determine the interrelationship between these identified barriers. Performance data obtained from this combined approach is applied to determine an overall rank for 15 identified barriers. The F-DEMATEL technique facilitates in obtaining the influence of barriers on each other and categorizes them into causal or effect groups. In addition, a Fuzzy Matrice d’impacts Croisés Multiplication Appliquée an un Classeement (F-MICMAC) analysis is exercised to sort them into dependent or driving factor. The findings suggest that the underlying cause barriers include “lack of customer awareness about return,” “less policies addressing e-waste problem,” “lack of long-term planning,” and “insensitiveness of public towards environmental issues.” The methodology is integrated with fuzzy logic to take uncertainty in the data gathered into consideration. This approach aids policymakers and decision-makers in determining the barriers’ mutual relationships and interconnections.
Among various materials available for alleviating the corrosion-related degradation, thermal sprayed Fe-based metallic glass coatings (MGCs) have received huge attention from the scientific community due to the exceptional combination of mechanical and corrosion properties, along with commercially attractive low material cost of this particular alloy system. Emerging reports on the thermal sprayed Fe-based MGCs outperforming conventional corrosion-resistant materials and coatings have accelerated further exploration of this domain, resulting in an immense increase of research activities over the last few decades producing fascinating results. This review takes a holistic approach encompassing an in-depth assessment of all the relevant salient work till date, including corrosion properties, corresponding degradation mechanisms, metallurgical and environmental factors with reference to passive film dynamics and/or formation of corrosion products. Moreover, various strategies for improved corrosion properties and recent research progress have been reviewed with an attempt to identify the present knowledge gaps and the future research directions.
SA333 Gr-6 steel is a candidate material for the primary cooling system in nuclear power plants. During service, piping components experience asymmetrical stress or strain cycling, resulting in plastic strain accumulation and a drastic reduction in fatigue life compared to symmetrical loading. This investigated steel is prone to the dynamic strain aging phenomenon. The present investigation deals with DSA and its influence on ratcheting deformation. Ratcheting tests were conducted at fixed load (σm = 50 & σa = 400 MPa) with varying temperatures from room temperature to 350 °C and stress rates (20-700 MPa s−1). Result reveals that the steel shows greater resistance to ratcheting strain and increased fatigue life at DSA dominant temperature regimes. The DSA is active at a temperature between 250 and 350 °C and the DSA regime gets shifted to a higher temperature with the increase in stress rate. Transmission electron microscopy (TEM) studies reveal severe dislocations activities and dislocation forest at DSA dominant specimen, whereas the arrangement of dislocations into well-developed cell structures at the non-DSA regime. TEM result is corroborated by calculating dislocation density from x-ray diffraction analysis, and it was found greater dislocation density at DSA dominant and lower at the non-DSA regime.
This article presents a computational reliability analysis of reinforced soil-retaining structures (RSRS) under seismic conditions. The internal stability of RSRS is evaluated using the horizontal slice method (HSM) with modified pseudo-dynamic seismic forces. Two different failure modes of RSRS are identified and their reliability indices are computed using the first-order reliability method (FORM). The critical probabilistic failure surface is identified using a three-tier optimization scheme. Reliability index of the system is computed by considering the modes of failure to be connected in series. The tension mode is found to be the most critical mode of failure. The present study identifies that the wall height (H), shear wave velocity of the soil (Vs), and predominant frequency of the input motion (ω) govern the response of RSRS. Reliability indices depend on a parameter termed as the normalized frequency (ωH/Vs) and their values decrease with an increase in the value of ωH/Vs. Increase in the damping ratio of soil, increases the value of reliability indices, especially for ωH/Vs values, which are close to π/2. The FORM suffers from few critical shortcomings such as linear assumption of limit state surface at the most probable point of failure and its ability to consider only the statistical uncertainties excluding the effect of epistemic uncertainties. This calls for sampling-based numerical techniques such as Monte-Carlo simulation (MCS) which gives more comprehensive understanding of the problem under consideration in a probabilistic framework. Thus, a computationally efficient surrogate-assisted MCS is carried out to validate the present formulation and provide numerical insights by capturing the system dynamics over the entire design domain. Adoption of the efficient surrogate-assisted approach allowed us to quantify the epistemic uncertainty associated with the system using Gaussian white noise (GWN). Subsequently, its effects on the system reliability index and probabilistic behavior of the critical parameters are presented. The numerical results clearly indicate that it is imperative to take into account the probabilistic deviations of the critical performance parameters for RSRS to ensure adequate safety and serviceability under operational condition while quantifying the reliability of such systems.
Nonlinear photonics is one of the options in the field of modern ultra-speed secured Information processing in optical communication. Switching action through Micro-ring Resonator can be used to implement all-optical sequence detector finite state machine mealy model and optical D flip-flop. The paper explained the switching action of the MRR structure along with the implementation of efficient all-optical 4-bit sequence detector using finite state machine mealy model for overlapping and non-overlapping scheme in a single unit using the proper arrangement of all-optical combinational circuits and D flip flops. The layouts and switching techniques of all-optical desired 4-bit sequence detector have been thoroughly described, and corresponding simulation results using MATLAB have been shown to verify the proposed unit's appropriateness. These techniques reduce the size of the optical circuit and make it more compact to incorporate with very large scale integrated optics (VLSIO). The proposed unit avoids the complex issues related to electro-optic and optoelectronics signal conversion. The analysis shows that implementation of sequence detector finite state machine (FSM) mealy model and clocked D flip-flop assists desired 4-bit sequence detector in the optical domain includes some significant advantages of secured optical communication. To attain an efficient range of device parameters, the manuscript discussed a detailed investigation of performance parameters for proper switching speed, extinction ratio, and contrast ratio of micro-ring resonator. Finally, the manuscript defines a competent technique to implement an all-optical MRR-based desired 4-bit sequence detector.
Exposure to polycyclic aromatic hydrocarbons (PAHs) through contaminated water may adversely affect human health and ecology. Water and sediment samples collected from the Mahanadi River Basin (MRB) were analyzed for the presence of sixteen priority PAHs. Results showed that the concentrations of Σ16 PAHs in water and sediments ranged from 13.1 to 685.4 μg/L and 302.6 to 728.2 ng/g. In river water samples, the highest mean concentrations were recorded for Acenaphthylene (18.73 ± 11.61 μg/L) and Benzo(a)Anthracene (10.11 ± 8 μg/L). On the contrary, the maximum concentration was recorded for Phenanthrene (96.18 ± 50.66 ng/g) and Pyrene (76.69 ± 22.73 ng/g) in sediment samples. Human health risk assessment suggests low risk, with incremental lifetime cancer risk (ILCR) being 37.44 × 10⁻⁵ for children and 21.82 × 10⁻⁵ for adults. In contrast, ecological risk assessment showed a high toxic equivalent quotient of 40.68 ng/g and mutagenic equivalent quotient of 39.74 ng/g suggesting elevated adverse risk to aquatic species.
Solar air heater is one of the important device for heating the air which is mainly used for space heating, timber seasoning, crop/vegetable drying, etc.. To improve the performance of solar air collectors, the fin plays an important role to increases the performances. Due to this reason in the present work, a novel type of solar air heater has been constructed with louvered fins and performed experiments to evaluate its thermal performance. The louvered fins have been attached to the bottom of the absorber plate to steer the flowing air and increase the heat transfer rate. To achieve this aim, the solar collector has been designed with the value of louvered angle, louvered length, louvered pitch & height taken to be 20°, 2.5 cm, 2.5 cm, and 3.5 cm, respectively, and conducted experiments with mass flow rate 0.007 kg/s to 0.0158 kg/s. The variations of insolation and fin spacing on the thermal efficiency and temperature rise have been also studied in the present experimental study. The results indicate that thermal efficiency increase with increasing flow rate, for a mass flow rate of 0.0158 kg/s and 0.007 kg/s, thermal efficiency and outlet temperature obtained a maximum of 70% and 58.66 °C respectively for spacing of 2 cm. further, observed that the thermal efficiency of louvered fin spacing 2 cm and 5 cm is higher as compared to plane solar air heater which is 106.7% and 59.45% respectively. The thermal performance of the louvered fins solar air heater is significantly enhanced as compared to that of the plane solar air heater.
Anthropogenic and natural sources influence trace metals (TMs) bound to different sized particulate matter (PM) in dry and wet atmospheric deposition, which can create ecosystem and human health issues in the long run. Limited reviews are available summarizing worldwide concentrations in TMs in atmospheric PMs, their sources and pathways. Simultaneously, quantitative assessment of the potential human and ecosystem health risks imposed by the atmospheric particulate matter has not been adequately reviewed. Addressing this gap, here we review, the concentration of TMs in dry deposition mainly varies with the responsible sources, whereas, in wet deposition, it depends on the solubility of TMs. Other than deposition on impervious surfaces, the TMs incorporated PM can be deposited on biological agents. Health risk assessments show that ingestion and dermal contact pathways are more likely to cause health issues, however, the probability of occurring ingestion and dermal contact pathways is limited. Attention must be paid to the contribution from non-exhaust and exhaust vehicular emissions for TMs in atmospheric deposition, understanding their impact on stormwater management and urban agriculture. Behaviors of TMs in the atmosphere depends on many complex factors including origin, wind patterns, and weather conditions. Therefore, future research needs to be carried to model and predict the fate and transfer of TMs once they are generated through natural and anthropogenic sources. We believe that such research would allow establishing pollution control policies and measures in urban environments which will be critical to reduce the levels of TMs associated with atmospheric deposition in the environment.
In the joint space, calculating the jerk-optimized trajectory of a redundant space manipulator is a significant issue in motion planning. The third derivative of desired joint trajectory position, known as a jerk, influences the smooth and effective movement of the manipulator. Using the conventional approach for multi-parameters selection, it is challenging to get an optimal solution. This can be taken care of by using an advanced optimization technique, grey wolf optimization which provides such search capabilities having the potential to produce optimum results. Therefore, to implement jerk-optimized motion planning, this work presents an approach based on grey wolf optimization, constrained by the joint inter-knot parameters in the joint space. It is expected that the proposed approach will impart the lowest joint jerk in comparison with other existing approaches like the genetic algorithm and particle swarm optimization. Consequently, minimal deviation of the joint trajectory can be observed at each joint. For various time intervals, minimal jerk values of the mean, maximum, and minimum for all joint angles are experienced compared to the genetic algorithm approach. Hence, smooth joint trajectories are generated for each joint, enabling the end-effector to move the desired pose with minimal jerk enhancing the stability of the manipulator.
Medium-Mn steels are one of the potential advanced high strength steels (AHSS) of third-generation, having an exceptional combination of high strength-elongation and crashworthiness. They have Mn in the range of 3–12 wt.% and consist of so-called “ultrafine-grained (UFG)” equiaxed or lath-like ferrite/martensite and retained austenite microstructure. The retained austenite content and its stability play a dominating role in influencing the properties of medium Mn steel as it delays the fracture or failure of the steel during deformation or event of a crash, via strain hardening mechanisms like “Transformation Induced Plasticity (TRIP)” and “Twinning Induced Plasticity (TWIP)” effects. The retained austenite amount and its stability can be tuned by adopting an appropriate intercritical annealing schedule, as it is influenced by various factors like the elemental composition of austenite, its grain size, morphology, etc. This article illustrates the evolution of medium-Mn steel, its microstructure, properties, and model for optimizing the retained austenite fraction, and factors influencing it.
The main aim of this paper is to address a novel exponentially fitted finite difference method for the treatment of a class of 2nd order singularly perturbed boundary value problems in ordinary differential equations with a simple turning point. Solution of such pervasive problem exhibits twin boundary layers when the perturbation parameter ε is small tending to zero. The method is most suitable for ε≤10-5 and is obtained by partitioning the domain into two subdomains. Taylor’s series with non symmetric difference approximations to the first derivative is used to derive new three term finite difference schemes valid over each of the two subdomains. Non-uniformity in the solution is resolved by the introduction of suitable exponential fitting factors in the derived schemes using the asymptotic theory of singular perturbations. At the turning point, the reduced equation is approximated by the use of central difference analogue of 2nd order derivative. Thomas algorithm is implemented on Code::BlocksIDEforFortran-90 platform for solving the resulting tridiagonal system of equations. Stability and Convergence of the method are analysed. Efficiency of the method is illustrated by solving three standard problems for ε≤10-5 and presenting the results in tabular/graphical form. Anewformula is introduced and used to know how much a method overcomes the other method(s). Comparisons made show the capability of the method in producing highly accurate and uniformly convergent results with linear rate for all the values of the mesh size h>>ε.
This research compares the performance of the models to estimate monthly mean diffuse solar radiation (DSR) on a horizontal surface for composite climatic region of India. The goal is to identify the most accurate model using deterministic and probabilistic analysis through two levels of uncertainty in daily sunshine period to examine the accuracy of the model, that will be used to estimate DSR in the region under consideration. The Meteorological data were collected from Indian Meteorological Department (IMD) for the city of New Delhi (28°34’N, 77°12’E) which comes under composite climatic region prescribed by the Energy Conservation Building Code (ECBC) for India. From the literature, 150 typical models were chosen and categorized into three categories correlating diffuse fraction to sky-clearness index and relative sunshine period. The models are statistically evaluated using well-known statistical indicators in a unique way. In addition, the Global Performance Indicator (GPI) is calculated using scaled values of indicators. The GPI of the chosen models ranged from -2.2912 to 0.2584, with the greatest value indicating the best model. Following that, the models are then ranked in decreasing order of GPI. Finally, the performances of the models are also checked for different locations having similar climatic conditions. Thus, results of this work are useful for impoverished countries as well as remote areas having similar environment conditions.
This article describes a frequency selective surface (FSS) for shielding with an improved angular stability over a wide frequency range. The proposed unit design consists of a circular ring in a square element, two cross dipoles, and a T‐type slotted structure printed of size 0.052 lambda0 × 0.052 lambda0 on a layer of FR4 substrate having a thickness of 0.0075 lambda0. Here lambda0 is the free‐space wavelength of lower cut‐off frequency. It has improved the bandwidth range from 2.84 GHz to more than 20 GHz enough to provide effective shielding against the entire ultra‐wideband (UWB) range, as well as the X– and Ku–bands. Up to 75 degrees of oblique incidence, the proposed design is polarisation independent and angularly stable. The structure is full wave simulated and an equivalent circuit model is realised. The findings are validated through the use of a fabricated prototype. The applications of shielding are in reducing electromagnetic interference in civil and military applications as well as improving the gain of UWB patch antennas.
One of the major challenge that organizations face in the present environment is having an efficient model for software cost estimation (SCE). In this article, the significance of the meta‐heuristic algorithm in addressing various optimization challenges faced in mathematical models and software applications is discussed. The proposed method uses the new evolutionism‐based self‐adaptive mutation operator to solve the multi‐objective optimization problems. This approach addresses the issues that exist in multi‐objective differential evolution algorithms. To improve diversity among candidate solutions, the Pareto optimality principle is integrated with the evolutionism‐based self‐adaptive mutation operator in a multi‐objective DE algorithm. To reduce the time complexity of Pareto dominance, we have adopted the non‐dominated sorting algorithm. We used eight benchmark test functions to evaluate the effectiveness of the proposed method, and it outperformed the most recent multi‐objective evolutionary algorithms (MOEAs). Furthermore, this article explores software engineering problems like SCE by using the proposed approach, where SCEs are accurately predicted by optimizing the tuning parameters of the multi‐objective constructive cost model. The proposed algorithm achieves better cost prediction as compared to the other standard benchmark algorithms for all objective problems in terms of prediction, mean absolute error, and root mean square error.
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1,260 members
Dr. Sunil Kumar
  • Department of Mathematics
Naveen Veldurthi
  • Department of Chemistry
Sanjay Kumar Vajpai
  • Department of Metallurgical and Materials Engineering
Raj Nandkeolyar
  • Department of Mathematics
Basudeba Behera
  • Department of Electronics and Communication Engineering
ADITYAPUR, 831014, Jamshedpur, Jharkhand, India
Head of institution