S. R. Ranganathan Learning Hub

Open Educational Resources (OER) has emerged in the last two decades with the swift growth of technology and its interventions in education. The Open Educational Resources (OER) have become popular among the educators. The primary objective of this study is to analyse global research trends on open educational resources. This analysis aims to understand the research landscape better, identify significant trends, and support informed decision-making. For this study, the data was derived from the Scopus scientometric database covering the period of 2013 to 2022. A total of 669 publications with 8332 citations were found during the search. Most publications published on the subjects are in social science (54%), followed by computer science (18%) and engineering (6%). Burgos, Hilton, and Wiley were the most prolific and impactful authors. It was found that for effective and impactful collaboration in two and three authors, 3.23 is the highest collaborative index, 0.90 is the collaborative degree, and 0.60 is the collaborative coefficient in 2022. The highly cited paper, “Ocean Basin Evolution and Global-Scale Plate Reorganization Events since Pangea Breakup by RD Muller, “ was published in 2016 and received 689 citations. The journal “International Review of Research in Open and Distance Learning” was the most preferred source. Also, highly productive institutes with Open Educational Resources, funding agencies and countries were observed.

The concept of "Open Educational Resources (OER)" is gaining eminence in the field of education on a global scale. The exponential growth of technology in the contemporary era has resulted in an unprecedented need for instant accessibility of information and services. Consequently, to investigate the effects of open educational resources on students in higher education institutions, a survey was conducted by the authors. The findings from the survey indicate that there exists a relatively low to moderate level of awareness regarding Open Educational Resources (OER) among students enrolled in higher education institutions in India. Besides, it was observed that the utilisation of OERs in higher education has a positive influence, suggesting the necessity to enhance awareness among students. By doing so, students can effectively utilise these resources to improve their academic performance.

This study unveils an innovative approach to fabricating H2S gas sensor prototypes for continuous monitoring, leveraging Pd-decorated CuCrO2-based metal oxide semiconductor (MOS) chemiresistors and artificial neural network-assisted impedance-based multivariate analysis. Sensors were exposed to H2S in cross-interfering environments containing humidity, NO2, NH3, CH4, H2, and CO2. Impedance-based parameters (Z, phase difference, Z′ and Z") obtained at various frequencies demonstrated that sensors were reproducible and selective for H2S detection. A neural network-based multilayer perceptron (MLP) regression model was trained with different impedance-based parameters to estimate the H2S concentrations. Continuous operation resulted in larger baseline variation for Z, Z′, and Z" readings; however, the measured phase difference values exhibited less depletion than other parameters. Furthermore, concerns about baseline changes were effectively addressed with a fine-tuned MLP model, which predicted both pure air and H2S atmospheres more correctly under cross-interfering and baseline-depleted conditions by employing phase differences at different frequencies as input. Possible reasons for the accurate prediction can be attributed to the confined behaviour of phase difference and discussed with the help of sensor statistical parameters such as mean variation, standard deviation and principal components. © 2024 Elsevier B.V.

In the present work, the relationship between microstructure and mechanical properties has been investigated for the dissimilar welded joint of P92 steel and Inconel 625, fabricated using the pulsed current gas tungsten arc welding (GTAW) process. Microstructural investigation revealed that the pulsed current resulted in finer equiaxed dendrites in the bulk weld metal, while columnar dendrites were observed in the weld metal near the interface. A more uniform distribution of the fine secondary phases was observed in FESEM study. The EDS study of the inter-dendritic areas showed alloying element segregation throughout the weld metal, with higher density near the interface. This segregation led to the formation of secondary phases, specifically MC-type carbides (NbC, TiC), which was confirmed by the EDS analysis. The characterization of the interface between P92 steel and ERNiCrMo-3 filler weld revealed the presence of a filler-deficient zone, marked by features such as islands, peninsulas, and unmixed zones. Elemental diffusion and segregation of Nb, Mo, and Ti at the interface were also confirmed through EDS analysis. Tensile testing demonstrated acceptable tensile properties of the welded joint at room temperature, with a tensile strength of 764 ± 8 MPa and elongation of 33 ± 1%, with the sample failing from the P92 base metal. Significant hardness variations were observed along the welded joint, with the most notable changes occurring in the P92 heat-affected zone (HAZ). A maximum hardness of 420 HV was recorded in the coarse-grained HAZ of P92, while the inter-critical HAZ of P92 showed a minimum hardness of 215 HV. In addition, considerable hardness variation was noted within the weld metal, corresponding to each welding pass as well as across the transverse direction of the welded joint. The maximum and minimum hardness values in the weld metal were 261 ± 9 and 239 ± 13 HV, corresponding to the center and capping passes, respectively, with an average hardness of 250 HV. The Charpy toughness test also indicated acceptable results, with an impact energy value of 176 ± 8.5 J. The study also provides a detailed discussion on the relationship between microstructure and mechanical properties, highlighting how microstructural features influence the mechanical performance of the welded joint. © Wroclaw University of Science and Technology 2025.

High-power lasers have been shown to be more effective for welding plates with thicknesses of 10 mm or greater. In the present research, a heat-resistant P92 steel plate was welded using the laser beam welding process. The laser-welded joint underwent mechanical testing and metallographic characterization in both the as-welded condition and after post-weld heat treatment (760 °C for 2 h). The macrostructure analysis revealed that the welded joint had full penetration with negligible internal defects. The widths of the heat-affected zone (HAZ), the weld metal at the top, and the weld metal in the root region were 1.77 mm, 3.83 mm, and 3.12 mm, respectively. Inhomogeneity in both the microstructure and microhardness was observed along the welded joint. The coarse-grained structure with negligible precipitates in the coarse-grained HAZ resulted in a maximum hardness of 432 HV, while a minimum hardness of 225 HV was measured in the inter-critical HAZ, likely due to the formation of a complex microstructure. Another important observation in the fine-grained HAZ and inter-critical HAZ was the presence of two types of grain boundaries: one decorated with a high density of precipitates and the other free from precipitates. This contributed significantly to the heterogeneity in the microstructure. The weld metal exhibited a lath-elongated martensitic microstructure, which showed significant hardness variation due to the presence of soft ferrite patches. The hardness of the untempered martensite in the weld metal ranged from 385 to 403 HV, with an average of 398 ± 7 HV. In contrast, the hardness of the soft ferrite patches was measured in the same range of 234–349 HV. The ultimate tensile strength and percentage elongation were 1014 ± 11 MPa and 27 ± 3%, respectively, which are significantly close to those of the P92 base metal, as fracture occurred in the P92 base metal. The Charpy toughness measured higher than the recommended value of 47 Joules, confirming the suitability of the welded joint for USC boiler applications. The PWHT significantly reduced the inhomogeneity in microstructure and mechanical properties, though some variation remained. There was a notable decrease in hardness for the weld metal, coarse-grained HAZ, and fine-grained HAZ after PWHT, while the hardness of the delta ferrite patches and inter-critical HAZ remained relatively unaffected, leading to continued microstructural heterogeneity. The tempering of martensite due to PWHT resulted in a drop in ultimate tensile strength and an increase in percentage elongation, with failure still occurring in the P92 base metal in the PWHT condition. Additionally, Charpy toughness increased significantly after PWHT, confirming the applicability of the PWHT for welded joints of P92 steel before final application. A good correlation between microstructure and mechanical properties was established based on these findings. © Wroclaw University of Science and Technology 2025.

Non-steroidal anti-inflammatory drugs (NSAIDs) are recommended to treat moderate-to-severe pain. Previous studies suggest that NSAIDs can suppress cellular proliferation and elevate apoptosis in different cancer cells. Ketorolac is an NSAID and can reduce the cancer cells' viability. However, molecular mechanisms by which Ketorolac can induce apoptosis and be helpful as an anti-tumor agent against carcinogenesis are unclear. Here, we observed treatment with Ketorolac disturbs proteasome functions, which induces aggregation of aberrant ubiquitinated proteins. Ketorolac exposure also induced the aggregation of expanded polyglutamine proteins, results cellular proteostasis disturbance. We found that the treatment of Ketorolac aggravates the accumulation of various cell cycle-linked proteins, which results in pro-apoptotic induction in cells. Ketorolac-mediated proteasome disturbance leads to mitochondrial abnormalities. Finally, we have observed that Ketorolac treatment depolarized mitochondrial membrane potential, released cytochrome c into cytoplasm, and induced apoptosis in cells, which could be due to proteasome functional depletion. Perhaps more in-depth research is required to understand the details of NSAID-based anti-proliferative molecular mechanisms that can elevate apoptosis in cancer cells and generate anti-tumor potential with the combination of putative cancer drugs. © 2024 International Union of Biochemistry and Molecular Biology.

The advanced ultra-supercritical (A-USC) power plant system is anticipated to become India's next-generation base-load power station. To adopt AUSC technology, dissimilar welded joints (DWJs) between heat-resistant steels and the nickel-based alloys, using the nickel-based fillers, will need to be implemented. However, failure of dissimilar welded joints from P92 steel base metal or the heat affected zone (HAZ) has been commonly observed under high-temperature creep conditions. In the present study, the creep rupture behaviours and rupture mechanisms of DWJ between the Ni-based alloy Inconel 617 and heat-resistant P92 steel with Inconel 617 (ERNiCrCoMo-1) filler metal were investigated. Creep tests were conducted at 650 °C in the stress range of 100–150 MPa. To examine the creep rupture behaviour of the DWJ samples, optical microscopy (OM), scanning electron microscopy (SEM) and microhardness tests were performed. Cross-sectional images of the fractured creep specimens tested under various operating conditions revealed failures originating from distinct locations, including the P92 base metal and the inter-critical heat affected zone (HAZ). The specimen tested at 650 °C/150 MPa exhibited failure originating from the P92 base metal, whereas the specimen tested at 650 °C under the stress range of 100–130 MPa showed failure from the inter-critical heat affected zone (ICHAZ). The failure from P92 BM was primarily governed by plastic deformation, with the growth and coalescence of dimples ultimately resulting in trans-granular fracture. The specimens tested at 650 °C/100–130 MPa, which failed from the ICHAZ, exhibited a typical Type IV inter-granular failure. This failure mode is primarily attributed to matrix softening in HAZ, weakening of the boundaries, coarsening of the precipitates, and the evolution of intermetallic Laves phases. The specimen that failed in the stress range of 100–130 MPa exhibited a high density of microvoids in the ICHAZ, along with a few microvoids in the FGHAZ. The weld metal showed negligible degradation in microstructure, while the hardness study revealed a significant increase in hardness with an increase in rupture time, i.e., a decrease in applied stress and it was attributed to evolution of the new carbide phases in weld metal. Coarsening of the carbide precipitates was observed in each zone of the HAZ of P92 steel as well as in the base metal. The EDS study of the fracture tip and the FGHAZ/ICHAZ of the specimen that failed under stresses of 100 MPa and 120 MPa confirmed the evolution of intermetallic Laves phases. High magnification SEM images confirmed that triple boundaries are preferential locations for microvoid nucleation. The failed specimen showed the presence of microvoids near the carbide precipitates, with a large density of both coarse and fine precipitates confirmed all around and inside the microvoids. The ICHAZ and FGHAZ confirmed the formation of fine prior austenite grain boundaries (PAGBs) during the welding thermal cycle, which exhibited a lower density of carbide precipitates and this played a major role in Type IV failure. © 2024 Elsevier Ltd