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The South American tomato moth, Phthorimaea absoluta (Meyrick), is one of the key pests of tomato in India. Since its report in 2014, chemical control has been the main means of tackling this pest, both in the open field and protected cultivation. Despite regular insecticidal sprays, many outbreaks were reported from major tomato-growing regions of South India during 2019–2020. A study was conducted to investigate the effect of insecticide resistance on biology, biochemical enzymes, and gene expression in various P. absoluta field populations viz., Bangalore, Kolar, Madurai, Salem, and Anantapur to commonly used insecticides such as flubendiamide, cyantraniliprole, and indoxacarb. Increased levels of insecticide resistance ratios (RR) were recorded in P. absoluta populations of different locations. A significant increase in cytochrome P450 monooxygenase (CYP/MFO) and esterase levels was noticed in the resistant population compared to susceptible one. Through molecular studies, we identified four new CYP genes viz., CYP248f (flubendiamide), CYP272c, CYP724c (cyantraniliprole), and CYP648i (indoxacarb). The expression levels of these genes significantly increased as the folds of resistance increased from G1 to G20 (generation), indicating involvement of the identified genes in insecticide resistance development in P. absoluta. In addition, the resistant populations showed decreased fecundity, increased larval development period, and adult longevity, resulting in more crop damage. The information generated in the present study thus helps in understanding the development of insecticide resistance by P. absoluta and suggests the farmers and researchers to use insecticides wisely by adopting insecticide resistance management as a strategy under integrated pest management.

Heart disease is among the leading causes of mortality globally. Predicting cardiovascular disease is a major difficulty in clinical data analysis. AI has been demonstrated to be powerful in deciding and anticipating an enormous measure of information created by the health domain. We provide a unique method for finding essential traits employing machine learning approaches in this paper, which enhances the effectiveness of identifying heart diseases. Decision tree (DT), support vector machine (SVM), artificial neural network (ANN), and K-nearest neighbor (KNN) are the classification techniques used to create the proposed system. Ensemble stacking integrates the four classification models to create a single best-fit predictive model using logistic regression. Many explorations have been directed at the identification of cardiac infection; however, the exactness of the outcomes is poor. Accordingly, to further enhance the efficiency, Moth-Flame Optimization (MFO) algorithm is proposed. The feature selection strategies are used to improve the classification accuracy while shortening the execution time of the classification system. Medical data are used to assess the probability of heart disease based on BP, age, gender, chest ache, cholesterol, blood sugar, and other variables. Results revealed that the proposed system excelled other existing models, obtaining 99% accuracy in the Cleveland dataset.

In recent times, nutrition recommendation system has gained increasing attention due to their need for healthy living. Current studies on the food domain deal with a recommendation system that focuses on independent users and their health problems but lack nutritional advice to individual users. The proposed system is developed to suggest nutritional food to people based on age and gender predicted from their face image. The designed methodology preprocesses the input image before performing feature extraction using the deep convolution neural network (DCNN) strategy. This network extracts D -dimensional characteristics from the source face image, followed by the feature selection strategy. The face’s distinctive and identifiable traits are chosen utilizing a hybrid particle swarm optimization (HPSO) technique. Support vector machine (SVM) is used to classify a person’s age and gender. The nutrition recommendation system relies on the age and gender classes. The proposed system is evaluated using classification rate, precision, and recall using Adience dataset and UTKface dataset, and real-world images exhibit excellent performance by achieving good prediction results and computation time.

This paper proposes a blend of three techniques to select COVID-19 testing centers. The objective of the paper is to identify a suitable location to establish new COVID-19 testing centers. Establishment of the testing center in the needy locations will be beneficial to both public and government officials. Selection of the wrong location may lead to lose both health and wealth. In this paper, location selection is modelled as a decision-making problem. The paper uses fuzzy analytic hierarchy process (AHP) technique to generate the criteria weights, monkey search algorithm to optimize the weights, and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method to rank the different locations. To illustrate the applicability of the proposed technique, a state named Tamil Nadu, located in India, is taken for a case study. The proposed structured algorithmic steps were applied for the input data obtained from the government of India website, and the results were analyzed and validated using the government of India website. The ranks assigned by the proposed technique to different locations are in aligning with the number of patients and death rate.

Diabetics are the significant progressive and chronic disease is characterized by the evaluated blood glucose level. It is mainly due to the production of insufficient insulin by the pancreas or when the body cannot effectively utilize the produced insulin. The raised glucose in future leads to serious damage to heart, blood vessels, eyes and kidneys. This is of various types and this control of insulin leads to death also. Proper yoga practices Meditation, diet and physical exercise are the vital components to control blood glucose. Effectively facilitates relaxation and calms the mind. When you breathe slowly and deeply, more oxygen circulates through the blood. Yoga is not a ‘cure all’ treatment and care should be taken to find the right medical condition, Regulate practices of yoga are very much useful for diabetics to keep the blood sugar level under control, as well as maintain the general health of the diabetics.

The purpose of the Random group experimental study was to find out the influence of Simplified Kundalini Yoga on selected Body Mass Index and Resting Pulse Rate among Obese School Girls. It was hypothesized that there would be significant differences in Body Mass Index (BMI) and Resting Pulse Rate among Obese School Girls due to the influences of Simplified Kundalini Yoga. To achieve the purpose of the study, 30 Obese (BMI of 30 to 35) school girls from Alagappa Group of Educational Institutions, Karaikudi, Sivagangai District aged between 14 to 18 years were selected randomly into experimental and control groups of 15 subjects each. The selected subjects were divided into one experimental group and a control group with 15 subjects each in a group. Experimental group underwent Simplified Kundalini Yoga for the period of 12 weeks, six days per week of 1 hour basically, then slightly increased to 1.15 hours and 1.30 hours in the morning. The control group was not exposed to any specific training but they participated in their regular activities. The pre-test and post- tests were conducted before and after the training for both the groups. The Body Mass Index (BMI) was measured by Weighing machine, Meter Scale and Resting Pulse Rate was measured by BP Monitor machine. The data pertaining to the variables collected from the two groups before and after their training period were statistically analyzed by using Analysis of Covariance (ANCOVA) to determine the significant difference. The hypotheses were tested at 0.05 level of confidence. The results of the study showed that Body Mass Index (BMI) and Resting Pulse Rate were decreased significantly as a result of Simplified Kundalini Yoga. Hence, the hypothesis was accepted at 0.05 level of confidence. The conclusion was that the Simplified Kundalini Yoga was effective in decrease Body Mass Index (BMI) and Resting Pulse Rate among Obese School girls.

South American tomato moth, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), is an oligophagous insect pest that infests solanaceous crops like tomato, brinjal and potato. The incidence of T. absoluta could cause significant yield losses of up to 100% on tomato crop and therefore farmers are following chemical management practices to tackle the pest. However, continuous and indiscriminate usage of certain insecticides may lead to development of resistance in T. absoluta. The aim of the study therefore was to know the level of resistance to different commonly used insecticides viz., indoxacarb14.5SC, flubendiamide 39.35SC, emamectin benzoate 5SG, spinosad 45SC, spinetoram 11.1SC and cyantraniliprole 10.25SC from different field population of T. absoluta viz., Bangalore and Kolar districts of Karnataka, Madurai and Salem districts of Tamil Nadu and Ananthpur district in Andhra Pradesh, India. A variable level of susceptibility of different field population of T. absoluta was noticed against frequently used insecticides viz. flubendiamide 39.35SC, cyantraniliprole 10.25SC and indoxacarb14.5SC. Biochemical assays indicated a significant increase in cytochrome P450 monooxygenase and esterase level in all relatively resistant population of T. absoluta. The cytochrome P450 monooxygenase and esterase enzymes therefore play a major role in the development of resistance in field population of T. absoluta. The reduced susceptibility of T. absoluta to various field collected population thus indicates a development of resistance to various insecticides necessitating the judicious use of chemicals for its management.

This paper focuses on studying the influence of texture on the deformation mechanism of oxide dispersion strengthened (ODS) 18Cr ferritic steel subjected to high-temperature tensile testing after consolidation by hot extrusion. The initial microstructure of the hot extruded steel showed preferential (1 1 0) planes alignment in perpendicular and parallel direction to extruded (ED) and transverse (TD), respectively. Two types of anisotropy have been highlighted: (1) A strong anisotropy of elongation properties with a transverse ductility is lower as compared to the axial ductility; (2) yield stress anisotropy (mechanical strength anisotropy) which is found to be temperature dependent. The material flow in 〈1 1 1〉 direction is observed during the application of load along extruded direction during the tensile test; however, (1 1 0) slip plane normal is parallel to the direction of loading for transverse direction and brings the Schmid factor to a lower level which makes slip activation unlikely. Deformation band is found to be aligned with the loading direction in the ED specimen and covering across a number of neighboring ferrite grains could be noticed irrespective of material flow. However, the areas near the grain boundaries in the microstructure are found to be the strain gradient regions. Further, it shows a preferential accommodation of strain in proximity to the boundary network for TD specimen. High temperature (973 K) tensile test in ED is found to promote grain-subdivision of elongated bands by dynamic recrystallization, and inverse pole figure distribution reveals a preferential increase in the intensity of clustering toward (1 1 1) plane parallel to the loading direction.

The evaluation and selection of state of transformers based on their mineral oil data are quite difficult. In this study, analytical hierarchy process (AHP) and technique for order preference by similarity to ideal solutions (TOPSISs) are used as the multi-criteria decision support methodologies to provide a simple approach to rank transformers based on their mineral oil data and to help decision makers to identify the transformer, which is in the most critical state. AHP is exercised for both priority weight calculation and ranking of transformers. The AHP method is used for weight calculation, and then transformers are ranked using TOPSIS. Here, data of 69 in-service and 12 failed transformers in Tamil Nadu state in India is collected for assessment. From the results, transformers with good insulation condition are ranked at top, while the transformers are given lower ranks if they are found to have bad health. It is proved that decisions yielded by both methods are in agreement with reality.

The insecticidal properties of leaf extracts of Carica papaya, Leucas aspera and seed extracts of Daturastramonium and Mucuna pruriens were evaluated against Aphis gossypii Glover (Hemiptera: Aphididae) under laboratory conditions. The mortality of aphids (80.0%) was more from D. stramonium seed extract (10ml/l) with LD50 of 0.39% followed by C. papaya leaf extract which caused mortality of 72.5% (10ml/l) with LD50 0.96%. The mortality of A. gossypii in M. pruriens seed extract was 70.0% with LD50 0.65% however the mortality was found to be non significant in L. aspera extract.

In the present work, ultra-fine powder of oxide dispersion strengthened Alloy 617 was synthesized by high energy ball milling. Milling parameters such as rpm and milling time were varied in the range of 500–2000 and 5–360 min, respectively. Energy applied to the powder in the milling process (Energy per unit mass per hit, Ec) was estimated using the collision model. Effect of milling parameters on the microstructure of powder and refinement of oxides was investigated using X-ray Diffraction (XRD), Scanning electron Microscopy (SEM), conventional Transmission Electron Microscopy (TEM) and High resolution Transmission Electron Microscopy (HRTEM). Desired convoluted lamellar structure with average particle size ∼33 μm was observed during milling at 1000 rpm (Ec ∼ 0.4 kJ/g.hit) for 6 h. TEM analysis of the powder showed the presence of fine oxide dispersoids in the size range 4–16 nm. HRTEM analysis substantiated the presence of fine dispersoids of size ∼4 nm and showed the presence of deformation twins in the matrix. The fine dispersoids in a nanocrystalline matrix is expected to provide superior creep strength to the material at high temperatures.

This paper aims at understanding the texture evolution in extruded oxide dispersion strengthened 18Cr ferritic steel during high-temperature uniaxial compression testing at 1,423 K at a strain rate of 0.01/s based on extensive electron back scatter diffraction characterization. The α-fiber texture is observed along the extrusion direction (ED) in the initial microstructure. The flow curves generated during uniaxial compression test are used to determine the associated hardening parameters. In addition, the degree of texture evolution after deformation along the ED and the transverse direction (TD) with respect to the initial condition has been predicted using VPSC-5 constitutive model. The prediction shows that the deformation along the ED produces a dominant γ-fiber texture in contrast to the TD. This is in agreement with the experimental results where γ-fiber texture is observed, due to enhanced dynamic recrystallization at high-temperature deformation.

Scheduling is a process of mapping resources to tasks and it’s objective is either one or more. This paper focuses on scheduling in heterogeneous multiprocessor systems. Here the resources are processing elements and tasks are the jobs submitted to the processor. The main objectives of multiprocessor scheduling are reducing schedule length, reducing the overall energy consumption, reducing the temperature, reducing failure rates and so on. A Hybrid dual-objective parallel genetic algorithm is applied in the proposed work. Makespan and energy consumption are the two objectives considered. The proposed algorithm determines the global optimal solutions by generating the initial population using some heuristics and then performing parallel genetic operations on it. The main aim of employing parallelism is to find a global optimum solution by avoiding premature convergence in a local optimum and to reduce the running time of the algorithm. Hill climbing is also used in addition, to avoid local optimum solutions. The proposed algorithm balances the tradeoff between energy consumption and makespan according to the inclinations of the users by following weighted sum methodology. Our experimental results demonstrate that the proposed algorithm outperforms the other existing algorithms in terms of both makespan and energy consumption by incurring less running time.

A motorized bellow-sealed valve in the steam generator leak detection circuit of fast breeder test reactor developed sodium leak while carrying out functional testing after providing temporary power supply to the valve. A systematic analysis of failed bellows along with the stem was carried out to understand the possible cause of the failure. Visual examination indicated that the bellows had suffered extensive twisting before failure. The cause for extensive deformation of the bellows is attributed to the failure of anti-rotation mechanism and high friction between the nut and the screw. This resulted in torsional loading on the bellows. Detailed finite element analysis showed that the bellows were safe during normal operating condition and, however, experienced extensive deformation due to the torsional loading. Systematic microstructural studies using scanning electron microscopy and defect and residual stress analysis using X-ray diffraction (XRD) were carried out. The microstructure of stem and bellows exhibits the presence of extensive slip bands and twins, which indicated that the failure occurred due to extensive plastic deformation. Large variation in hardness and defect density as revealed by XRD analysis from different locations of the failed bellows supports the above observation. The presence of large number of twins in different locations shows that the component has experienced severe stress due to torsional loading.

This paper presents the results of an experimental and computational study carried out to elucidate the effect of Al on the microstructure and phase stability of P91 F/M steel in as-cast, homogenized and normalized conditions. Al-added steels followed ‘Ferritic-Austenitic’ mode of solidification and the as-cast microstructures consisted of δ-ferrite + α′-martensite, the volume fraction of ferrite and hardness of martensite increased with Al concentration. Heat treatments and DSC experiments confirmed increased stability for δ-ferrite with Al addition. Systematic change in the phase transformations temperatures and volume fraction of equilibrium phases due to Al addition was estimated with the help of Thermo-Calc®. Al addition promoted the formation of AlN which was confirmed through electron microscopy-based investigations. AlN dissolution temperature was always above γ-loop which made it impossible to dissolve during austenization. With the help of Scheil and equilibrium simulations using Thermo-Calc®, elemental partitioning between δ-ferrite and α′ phases was found to be the reason for higher hardness of martensite. Based on experimental evidences, it is concluded that except in the case of 0.48 wt pct Al-added steel it is impossible to obtain single phase γ-field (without ferrite) at high temperature thereby a fully martensite structure on cooling.

This paper presents the results of an experimental study aimed to identify hot working domains in oxide dispersion strengthened (ODS) 18Cr ferritic steel over a wide range of temperatures (1323-1473 K) and strain rates (0.01-10 s−1). The experimental data were obtained by uniaxial compression test using the Gleeble-1500D simulator in this range of temperature and strain rate. An inverse relationship with temperature and positive strain rate sensitivity associated with dynamic recovery and recrystallization, which is influenced by temperature and strain rate, was derived from the flow stress. Based on the processing map generated at 0.5 true strain, using rate dynamic material model (DMM) approach and the calculated instability parameter $$\left( {\xi \left( \acute{\epsilon} \right)} \right) > 0$$ , the optimum processing domain has been determined for this steel. The most favorable processing parameters are found in the temperature ranges of 1350-1450 K with a strain rate of 0.01 s−1 and 1473 K with a strain rate 0.1 s−1 with peak efficiency of 30 and 35%, respectively. The material flow behavior was studied using scanning electron microscopy (SEM)-based EBSD microstructural characterization. The steel subjected to 1323 K at high strain rate 10 s−1 in the low-efficiency workability region showed low aspect ratio as compared to the elongated bamboo-like initial microstructure; however, minimum strain rate (0.01 s−1) showing that localized slip/shearing is the key mechanism and fiber texture studied from the intensity distribution of inverse pole figure showed the presence of significant amount of θ-fibers. In contrast, dynamic recrystallization dominated at higher efficiency region in the safe domain of processing map and γ-fiber texture was evident in the specimen deformed at 1373 and 1473 K with strain rate of 0.01 and 0.1 s−1, respectively, which is responsible for the change in the initial 〈1 1 0〉//ED α-fiber texture.

This paper presents the results of an experimental study to investigate the structural and microchemical characteristics of an equiatomic CrFeNbNiV alloy. XRD analysis of CrFeNbNiV alloy, revealed a predominant NbCrNi type HCP Laves phase conjoined with two minor tetragonal and BCC phases. Detailed microstructural investigations using electron microscopy techniques also substantiated the presence of the above mentioned phases. The structure of Laves phase in this alloy is determined ab initio for the first time using Precession Electron Diffraction technique which was in agreement with the Rietveld analysis of XRD pattern. The formation of intermetallic Laves phase was understood based on theoretical phase stability and average d- orbital energy level $$\overline{\text{Md}}$$ value calculations. The alloy in the ‘as cast’ condition exhibited a very high value of hardness (~ 1500 Hv). No change in the microstructure and hardness was observed on annealing at high temperatures even up to 1373 K (1100 °C).

This paper presents the results of an experimental study on evolution of the nanocrystalline microstructure in a mechanically alloyed Oxide dispersion strengthened (ODS) 18Cr ferritic steel powder during densification by spark plasma sintering (SPS) in the temperature range of 1273 K (1000 °C) to 1423 K (1150 °C). Systematic Electron Back-Scatter Diffraction analysis has been carried out to study the grain size distribution and texture as a function of consolidation temperatures. Based on the kinetics of the densification process and resultant microstructure/microtexture, a sintering temperature slightly above 1323 K (1050 °C) within a range of 50 K was found to be optimum. The 18Cr-ferritic steel powder consolidated at 1323 K (1050 °C) was also studied to understand the role of dispersoids on microstructure. The dispersoids exerted a profound influence on the strength as well as toughness of the steel by restricting the grain growth at high temperatures. Further, a signature of (1 1 0) grain cluster is observed during consolidation and its preferential growth with increase in sintering temperature is noticed which lead to the alignment of the (1 1 0) plane in the direction of applied pressure. The minimum creep rate of the consolidated steel under a load of 300 MPa was found to be 5E-7 h−1 and 1E-4 h−1 at 873 and 973 K (600 and 700 °C) respectively. The apparent activation energy for creep deformation was estimated as ~ 402 kJ/mol, which is typical of lattice diffusion assisted general climb mechanism of dislocations over the barriers such as present dispersoids.

This paper proposes a new tri-objective scheduling algorithm called Heterogeneous Reliability-Driven Energy-Efficient Duplication-based (HRDEED) algorithm for heterogeneous multiprocessors. The goal of the algorithm is to minimize the makespan (schedule length) and energy consumption, while maximizing the reliability of the generated schedule. Duplication has been employed in order to minimize the makespan. There is a strong interest among researchers to obtain high-performance schedules that consume less energy. To address this issue, the proposed algorithm incorporates energy consumption as an objective. Moreover, in order to deal with processor and link failures, a system reliability model is proposed. The three objectives, i.e., minimizing the makespan and energy, while maximizing the reliability, have been met by employing a method called Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS). TOPSIS is a popular Multi-Criteria Decision-Making (MCDM) technique that has been employed to rank the generated Pareto optimal schedules. Simulation results demonstrate the capability of the proposed algorithm in generating short, energy-efficient and reliable schedules. Based on simulation results, we observe that HRDEED algorithm demonstrates an improvement in both the energy consumption and reliability, with a reduced makespan. Specifically, it has been shown that the energy consumption can be reduced by 5–47%, and reliability can be improved by 1–5% with a 1–3% increase in makespan.

The current study examines the evolution of nanocrystallites of ZrO2 with time and temperature in a Fe-ZrO2 composite. The crystallite sizes were determined through X-ray peak broadening analysis by the Williamson–Hall method together with dark field transmission electron microscopy. The ZrO2 crystallites were found to be stable and retained their sizes at 973 K and 1073 K for hold durations up to 600 minutes. On the other hand, the crystallites were seen to grow at 1173 K and reached up to ~ 200 nm for a hold time of 600 minutes. The Ostwald ripening model was adopted to understand crystallite growth while a dislocation-driven pipe diffusion was adopted for understanding the kinetics of grain growth. The activation energy of grain growth was calculated as ~ 379 kJ mol−1. The modeled and experimentally calculated size evolutions with time and temperature were shown to be in good agreement with each other. A detailed discussion on the kinetics and activation energy of grain growth of ZrO2 crystallites in a Fe matrix is presented in this manuscript.

Diffusion of a single Fe atom in a defect free hcp Ti lattice was studied using molecular dynamics (MD) simulation. Modified Embedded Atom Method potentials derived by Sa et al. (Scripta Mater 59:595, 2008) were used for carrying out the MD simulations. These potentials were verified by estimating the physical properties of the Fe–Ti system such as cohesive energy, bulk modulus and the shear constants. Fe atom trajectory in Ti lattice was traced in the temperature range of 500–900 °C. Diffusivity of Fe ( $$ D_{Fe} $$ ) atom in Ti lattice was obtained from the estimation of mean square displacement for total time of simulation at each temperature. $$ D_{Fe} $$ at 900 °C was obtained as 7.784 × 10−15 m2/s. From the Arrhenius analysis of $$ \ln D_{Fe} $$ versus temperature, the activation energy required for the diffusion of Fe atom in hcp Ti lattice was obtained as 117 kJ/mol.

This paper presents the results of a study on grain boundary characteristics in cold deformed and annealed 304HCu grade austenitic stainless steel (SS 304HCu) using electron backscatter diffraction. The microstructure exhibited an increasing fraction of Σ1 to 29 coincidence site lattice boundaries with annealing temperature, resulting up to ~60 pct at 1573 K with 92 pct contribution from Σ3-type twin boundary. However, the twin boundary interaction at the triple points with a network of Σ3–Σ3–Σ9 was found to decrease from 4 to 0.5 pct with annealing temperature. To understand the resultant boundary advancement of the Σ3 n (n = 1, 2, 3) boundaries, their migration was traced in the annealed specimen. However, in the specimen with extended annealing Σ3 boundary fraction was found to be higher with a concomitant decrease in the boundary fraction generated by the Σ3 interactions. In this study, a procedure to analyze the coherency of Σ3 boundaries and its interfaces that form due to Σ3 interactions has been evolved based on single-section analysis using the pole concentration across the grains. Further, a crystallographic description of the two planes meeting at the interface of Σ3-type boundary has been provided by adopting serial sectioning methods, which help to understand the morphological changes. The quantitative deviation from exact coherent Σ3 has been estimated to be within ~6 deg in this study.

A novel ODS ferritic steel with ZrO2 dispersoids is developed as a candidate structural material for future fast reactor applications. Encouraged by our earlier results demonstrating the retention of crystallinity by ZrO2 dispersoids during milling, the 9Cr ODS steel powder has been synthesized under optimized ball milling conditions and subsequently characterized. The analysis of milled powder showed fine dispersions of ZrO2 with a size range of 2–10 nm. Upon annealing at 1223 K, precipitation of non-stoichiometric FeO was observed along with fine ZrO2 dispersoids. All the constituent phases are identified using Synchrotron XRD, Conventional and HRTEM. An excellent thermal stability has been manifested by the dispersoids as it retained its fine structure during the annealing treatment with ~ 95% of dispersoids measuring

This study presents an extensive experimental characterization of high temperature phase stability and phase transformation kinetics of intermetallic sigma and alpha phases of Fe 55 Cr 45 alloy carried out by dynamic calorimetry. Sigma phase was synthesized from its parent alpha phase of Fe 55 Cr 45 alloy by annealing at 973 K for 360 h in vacuum. A comparative thermal study of sigma and alpha phase alloy was performed from 373 to 1400 K by Differential Scanning Calorimeter. Single inflection of ferro to para magnetic transition (T c ) was observed in DSC upto melting at 831 K for alpha phase. For sigma phase, the sigma to alpha decomposition temperature was measured as 1122 K. It was observed that sigma phase decomposition temperature is nearly 30 K higher than the presently reported 1093 K. Kinetics study of sigma to alpha phase transformation has been carried out by employing various heating rates from 1 to 50 K min −1 in DSC. The non isothermal KJMA model has been adopted to model the fraction transformed to determine the order and kinetics parameters. The activation energy for sigma to alpha phase transformation was obtained 240–260 kJ mol −1 by employing KJMA model.

In the present study, the feasibility of employing the indigenously developed ferroboron alloy (Fe-15 wt.%B) as an alternate neutron shield material in combination with 9Cr-based ferritic steel (P91) clad in future Indian fast breeder reactors (FBR), has been investigated from a metallurgical perspective. Towards this goal, a series of diffusion couple experiments have been conducted at three different temperatures namely, 600, 700 and 800 °C for time durations up to 5000 h. The thickness of interaction layer has been monitored using standard metallographic procedures. The experiments revealed that ferroboron/P91 combination exhibited a tendency to form complex intermetallic borides at the interface. The structural and microstructural characterization of the interface confirmed that the reaction layer consists predominantly of borides of Fe and Cr of type FeB, Fe 2 B, (Fe,Cr) 2 B and (Fe,Cr)B. The measured variation of interaction layer thickness as a function of time and temperature have been modelled in terms of diffusion mediated interaction. The growth kinetics of borided layer has followed the parabolic law at each temperature, and the apparent activation energy for boride layer formation is found to be of the order of 115 kJ mol −1 . This indicates that the kinetics of boriding could be governed by diffusion of B into the P91 matrix. Based on the findings of present study, an extrapolative estimate of the clad attack thickness at 550 °C for 60 years of operating time has been made and it turns out to be 210 ± 15 μm, which is less than the clad thickness of FBR shielding subassembly (4 mm) [1]. Thus, this study confirms that at testing temperatures from 550 to 600 °C, the ferroboron/P91 steel combination can be safely employed for shielding subassembly applications in fast reactors.

This article presents the results of an experimental study on the evolution of phases during annealing of ball milled Fe – ZrO2 nanocomposite powder using Differential Scanning Calorimetry, X-ray Diffraction and Electron Microscopy techniques. The formation of FeO phase from Fe and Fe3O4 is identified through Differential Scanning Calorimetry and confirmed using Synchrotron Diffraction and Transmission Electron Microscopy. Qualitative X-ray phase analysis showed the stoichiometry of the FeO phase as Fe0.87O. This phase is expected to be beneficial as it offers strengthening in the Fe matrix and is thermally stable. The activation energy of formation of the Fe0.87O phase was estimated to be ~ 195 kJ mol− 1. This phase is also found to be partially stabilizing the cubic phase of ZrO2, at high temperatures. A cubic ⇆ tetragonal transformation of ZrO2 was identified at 1140 K. A rather broad peak was observed for Fe α → γ transformation in the Calorimetry thermograms as the Fe grains were nanocrystalline which became sharper as the crystallites grew in size.