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Modelling of two modes of continental crust formation suggests that before plate tectonics began operating, the Archean early Earth’s tectonic regime was governed by intrusive magmatism. Earth's primordial squishy lid The global geodynamic regime of early Earth, which was in operation before the onset of plate tectonics during the Archaean eon over 2.5 billion years ago, remains contentious. Antoine Rozel et al. use numerical models of global thermochemical convection, including magmatic processes, to show that a tectonics regime dominated by intrusive molten rock results in warm crustal geotherms and can reproduce the observed proportions of primordial continental crust. They therefore conclude that the early Archaean Earth operated globally in a 'Plutonic squishy lid' regime in which intrusions of magma solidified into igneous rock deep below Earth's surface, rather than in an ‘Io-like’ regime dominated by extrusive volcanism. The global geodynamic regime of early Earth, which operated before the onset of plate tectonics, remains contentious. As geological and geochemical data suggest hotter Archean mantle temperature 1 , 2 and more intense juvenile magmatism than in the present-day Earth 3 , 4 , two crust–mantle interaction modes differing in melt eruption efficiency have been proposed: the Io-like heat-pipe tectonics regime dominated by volcanism 5 , 6 and the “Plutonic squishy lid” tectonics regime governed by intrusive magmatism, which is thought to apply to the dynamics of Venus 7 , 8 , 9 . Both tectonics regimes are capable of producing primordial tonalite–trondhjemite–granodiorite (TTG) continental crust 5 , 10 but lithospheric geotherms and crust production rates as well as proportions of various TTG compositions differ greatly 9 , 10 , which implies that the heat-pipe and Plutonic squishy lid hypotheses can be tested using natural data 11 . Here we investigate the creation of primordial TTG-like continental crust using self-consistent numerical models of global thermochemical convection associated with magmatic processes. We show that the volcanism-dominated heat-pipe tectonics model results in cold crustal geotherms and is not able to produce Earth-like primordial continental crust. In contrast, the Plutonic squishy lid tectonics regime dominated by intrusive magmatism results in hotter crustal geotherms and is capable of reproducing the observed proportions of various TTG rocks. Using a systematic parameter study, we show that the typical modern eruption efficiency of less than 40 per cent 12 leads to the production of the expected amounts of the three main primordial crustal compositions previously reported from field data 4 , 11 (low-, medium- and high-pressure TTG). Our study thus suggests that the pre-plate-tectonics Archean Earth operated globally in the Plutonic squishy lid regime rather than in an Io-like heat-pipe regime.

In a class of single field models of inflation, the idea of primordial black holes (PBHs) production is studied. In this case, the dynamics on small cosmological scales differs significantly from that of the large scales probed by the observations of cosmic microwave background (CMB). This difference becomes a virtue in producing correct physical ambiance for the seeds required to produce PBHs. Thus, once the perturbed scales re-enter the horizon of our Universe during the later epochs of radiation domination and subsequent matter domination, these seeds collapses to produce PBHs. We have shown, in this class of model, depending on the model parameters and the class defining set parameters, one can have PBHs formed for a vast mass ranges from 10-18 to 10-6 solar mass (M⊙). We have also shown, for a particular class of model, the total dark matter density today can be attributed to the PBHs density. The vast range of the mass depending on the class parameter, gives ample opportunity to study enriched phenomenological implications associated with this model to probe the nascent Universe dynamics.

Unprotected surfaces where a coating has been removed due to erosive wear can catastrophically fail from corrosion, mechanical impingement, or chemical degradation, leading to major safety hazards, financial losses, and even fatalities. As a preventive measure, industries including aviation, marine and renewable energy are actively seeking solutions for the real-time and autonomous monitoring of coating health. This work presents a real-time, non-destructive inspection system for the erosive wear detection of coatings, by leveraging artificial intelligence enabled microwave differential split ring resonator sensors, integrated to a smart, embedded monitoring circuitry. The differential microwave system detects the erosion of coatings through the variations of resonant characteristics of the split ring resonators, located underneath the coating layer while compensating for the external noises. The system’s response and performance are validated through erosive wear tests on single- and multi-layer polymeric coatings up to a thickness of 2.5 mm. The system is capable of distinguishing which layer is being eroded (for multi-layer coatings) and estimating the wear depth and rate through its integration with a recurrent neural network-based predictive analytics model. The synergistic combination of artificial intelligence enabled microwave resonators and a smart monitoring system further demonstrates its practicality for real-world coating erosion applications. Real-time monitoring of coatings erosive wear is critical to mitigate safety and financial concerns in many applications. Here, authors show a non-destructive inspection system with AI-enabled microwave resonators and a smart monitoring circuitry to identify and estimate wear depth and rate of eroded layers.

Some papers presented at a seminar on \"Indian diaspora in the Gulf countries\" on 19th March, 2009.

The Norton-Bass (NB) model is often credited as the pioneering multigeneration diffusion model in marketing. However, as acknowledged by the authors, when counting the number of adopters who substitute an old product generation with a new generation, the NB model does not differentiate those who have already adopted the old generation from those who have not. In this study, we develop a generalized Norton-Bass (GNB) model that separates the two different types of substitutions. The GNB model provides closed-form expressions for both the number of units in use and the adoption rate, and offers greater flexibility in parameter estimation, forecasting, and revenue projection. An appealing aspect of the GNB model is that it uses exactly the same set of parameters as the NB model and is mathematically consistent with the later. Empirical results show that the GNB model delivers better overall performance than previous models both in terms of model fit and forecasting performance. The analyses also show that differentiating leapfrogging and switching adoptions based on the GNB model can help gain additional insights into the process of multigeneration diffusion. Furthermore, we demonstrate that the GNB model can incorporate the effect of marketing mix variables on the speed of diffusion for all product generations. This paper was accepted by Pradeep Chintagunta, marketing.

Deterioration in the groundwater quality is prevalent in many parts of the eastern and north-eastern India; however, little attention has been paid for its assessment. In order to evaluate the groundwater suitability in the north-eastern region of India, this study was carried out in Barpeta District of Assam. The groundwater samples were collected from various locations to represent the overall water quality of the district. Suitability was assessed in terms of its usability for drinking and irrigation. It was found that the groundwater samples are contaminated with high amount of arsenic, which refers that water is unfit for consumption as well as agricultural activities. Hydrogeological studies revealed that regional geological factors might be responsible for excess arsenic concentration in the region. Overall, groundwater quality was found to be alkaline having moderate hardness with high amount of iron, manganese, and lead as well.