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Migrant labourers in India face increased heat stress driven by climate warming and ENSO variability
No full textMigrant labourers typically work long hours at physically demanding tasks without air conditioning, and they account for a considerable fraction of India�s population � a share that is increasing with urban growth. However, changes in heat stress and labour capacity in major urban centres that attract rural-to-urban work migrants remain unexplored. Moreover, it remains unclear how the increased heat stress and reduced labour capacity under the warming climate will alter the most preferred workplaces for migrant labourers in India. Here, we use station-based observations, reanalysis, and climate model projections to reconstruct trends and variability in heat stress metrics, including wet-bulb temperature (Tw for indoor exposure) and wet-bulb globe temperature (WBGT for outdoor exposure). We show that during 1980-2021, most rural-to-urban migration hotspots in north, east, and southern India witnessed a significant (p < 0.05) rise in Tw, indicating elevated indoor heat stress. Over that interval, outdoor heat stress has considerably increased and led to a ~10% decline in labour capacity in these hotspots. A substantial rise in the indoor and outdoor heat stress exposure of migrants and a reduction in their physical labour capacity is projected with each additional degree of global warming. El Nino-Southern Oscillation variability can also significantly enhance these effects. Effective mitigation and adaptation options are needed to reduce the risks migrant workers face due to increasing indoor and outdoor heat stress in India
Experimental analysis on the effect of overburden stress on the smear zone characteristics of clayey soil
No full textPreloading with vertical drains is a well-proven ground improvement technique suitable for soft clay deposits. This technique involves installing vertical drains that cause soil remolding in the immediate vicinity of its surface, creating a disturbed zone known as the smear zone. This study aims to investigate the impact of overburden stress on the characteristics of the smear zone. Very often, the vertical drains penetrate to depths up to 20 m. In such situations, the soil experiences varying stresses, leading to different responses to the drain-induced soil disturbances. Very few studies have investigated how overburden stress affects the smear zone. Through a series of experiments encompassing vertical and radial consolidation tests, along with vane shear tests, this paper evaluates the variation in shear strength and consolidation properties within the smear zone, simulating different depths. Employing three overburden pressure intensities (25 kPa, 50 kPa, 100 kPa, equivalent to depths of about 4 m, 8 m and 16 m), the study establishes that the remolding effect intensifies with depth. Furthermore, it demonstrates the influential role of the smear zone on the undrained shear strength properties of the improved ground, highlighting its variability based on overburden stress
Impact of chlorine substitution on supramolecular architecture and non-covalent interactions in Ethyl 2-amino-6-chloro-4-aryl-7-hydroxy-4H-benzo[4,5-e]pyran-3-carboxylate Isomers: a combined experimental, crystallographic, theoretical, and antioxidant study
No full textTwo positional isomers, ethyl 2-amino-6-chloro-4-(2-chlorophenyl)-7-hydroxy-4H-benzo-[4,5-e]pyran-3-carboxylate (1) and ethyl 2-amino-6-chloro-4-(3-chlorophenyl)-7-hydroxy-4H-benzo- [4,5-e] pyran-3-carboxylate (2) were synthesized by a one pot multi-component reaction (MCR) between 4-chlororesorcinol, ethyl cyanoacetate, 2-/3-chlorobenzaldehyde and K2CO3 as a catalyst. Structure establishment was made by UV–Vis., FT-IR, 1H and 13C NMR spectroscopy, and confirmed by single-crystal X-ray diffraction analysis. Both compounds crystallized as monoclinic crystal system with P21/c for compound 1 and C2/c space group for compound 2, respectively. The Hirshfeld surface analysis suggests that the intermolecular H···H, H···Cl, H···O, and H···C contacts significantly contribute their crystal packing. The relative contribution of these contacts is comparable in both compounds and the isomeric effect is very marginal. However, a significant deviation is observed in the H···H and C···Cl contacts. The solid-state arrangements of these two isomers are quite similar, with comparable lattice energies. The Coulomb-London-Pauli-PIXEL (CLP-PIXEL) energy analysis identified the most significant intermolecular dimers in the crystal packing with respect to the total intermolecular interaction energy. These molecular dimers are held together by different non-covalent interactions, such as N − H···O, O − H···O, C − H···O, C − H···Cl, C − H···π, halogen bond and other molecular stacking interactions. The strength of the intra- and intermolecular interactions was evaluated using the quantum theory of atoms in molecules (QTAIM) approach. The UV–Vis absorbance (in chloroform) of compounds 1 and 2 are very similar and this experimental result is in good agreement with the time-dependent density-functional theory (TD-DFT) calculations. The compounds 1 and 2 were examined for antioxidant activity using DPPH assay. The results revealed that the two compounds possess potential antioxidant activity in combating oxidative damage
2D and 3D characterization of desiccation cracking in compacted expansive soils using digital image processing
No full textPore Pressure Response of Natural Soils Under Various Testing Conditions
No full textSoil behavior under undrained conditions is governed by several factors, including soil density, fines content, plasticity index and loading conditions among many others. Constitutive behavior of soil being pressure-dependent, the undrained response of soils is dictated by the development of excess pore water pressure during the applied loading. In this study, the pore pressure response of the natural Kutch soils under monotonic compression triaxial (TX), cyclic triaxial (CTX), and cyclic simple shear (CSS) conditions was investigated at their in-situ density. The explored soils vary greatly in terms of gradation, fines content, and nature of fines. The development of excess pore water pressure was compared under the three loading conditions and was analyzed in the context of fines content and plasticity index of the soils. The excess pore pressure ratio at peak stress for TX was found to be lower than that during the first cycle for both the CTX and CSS. However, at critical state, the excess pore pressure ratio for TX was higher than that during the 5th cycle for CTX and CSS. Under cyclic conditions,�for a given number of cycles, the excess pore water pressure ratio under CSS conditions was always higher than that under the CTX conditions, signifying overestimation of liquefaction resistance as evaluated from the CTX tests. With an increase in�the fines content and plasticity index, excess pore water pressure was observed to decrease under all the three loading conditions. � 2021 Elsevier B.V., All rights reserved
Investigating the 4D3/2|3,±2) - 4D5/2|3,±2) transition in Nb4+ for a THz atomic clock
No full textIn this work, the 4D3/2|3,±2)→4D5/2|3,±2) transition in the Nb4+ ion is identified as a promising candidate for a terahertz (THz) atomic clock, with the transition frequency occurring at 56.022 4 THz. This transition is primarily driven by the magnetic dipole decay channel, which can easily be accessed by a laser. We focus on the stable Nb93 isotope, which has 100% natural abundance and a nuclear spin of I=9/2 for experimental advantage. Our data analysis allows us to estimate potential systematic shifts in the proposed clock system, including those due to blackbody radiation, electric quadrupole, second-order Zeeman, and second-order Doppler shifts. The scheme presented in this study can help suppress the ac Stark and electric quadrupole shifts in the clock-frequency measurement. All these analyses suggest that the proposed THz atomic clock using Nb4+ could be valuable in both quantum thermometry and frequency metrology
Design-Analysis of CNTFET-Based Energy Efficient Ternary Logic Gates
No full textCarbon nanotube field-effect transistors (CNTFETs) show great potential for designing multiple-valued logic (MVL) gates due to their exceptional electrical properties, such as the ability to control threshold voltage by adjusting the chirality of the carbon nanotube. This makes CNTFETs stand out as promising candidates when compared to conventional and other emerging device technologies. MVL represents more data or information than binary logic using the same number of logic bits. Energy-efficient ternary logic gates like standard ternary inverter (STI), ternary NAND (TNAND), and ternary NOR (TNOR) gates have been proposed. The use of transmission gates, pass transistors, and two power supplies has led to a significant reduction in power consumption in the proposed circuits. The power-delay-product (PDP) for the proposed STI, TNAND, and TNOR is reduced by 70.38%, 77.27%, and 39.8%, respectively, compared to the lowest PDP among the designs being evaluated
Design of a digitized Indian aphasia battery (dIAB) and investigating the performance of post-stroke Individuals and healthy Individuals
No full textA note on eigenvalue of tensors and its application
No full textThe tensor eigenvalue problem has been widely studied in recent years. In this paper, several new properties of eigenvalues and determinants of tensors are explored. We also proposed a formula to compute the determinant of a tensor as a mimic of the matrix determinant. The Perron-Frobenius theorem, one of the most important results in non-negative matrix theory, is proposed for the class of non-negative tensors in the Einstein product framework. Further, the power method, a widely used matrix iterative method for finding the largest eigenvalue, is framed for tensors using the Einstein product. The proposed higher-order power method is applied to calculate the largest eigenvalue of the Laplacian tensors associated with hyper-stars and hyper-trees. The numerical results show that the higher-order power method with the Einstein product is stable
A Hysteretic-Controlled Digital LDO Regulator for Enhanced Load Transient Response
No full textThis work presents a digital low dropout (DLDO) regulator design with integrated hysteretic control (HC) for improved load transient response towards power management applications in low-power low-voltage systems. The proposed control mechanism operates parallel to the DLDO's standard shift-register (S/R) control during the load transient events, i.e., when the output voltage crosses the preset voltage regulation window, and improves the transient response by providing auxiliary paths for sourcing and sinking current. The proposed HC-integrated DLDO, designed and simulated in a 65 nm CMOS process, achieves ∼4× improved transient response time and ∼5× reduced undershoot voltage over a standard DLDO for a load current step-change of ∼6.5 mA. The peak current efficiency and figure of merit are 99.8 % and 81.05 ps, respectively