IMPACT OF SOLAR RADIATION AND HEAT TRANSFER ALONG THE RIVER DAMODAR

This study investigates the impact of solar radiation and heat transfer processes along the Damodar River, emphasizing their influence on riverine thermal dynamics and ecological processes. Solar radiation is a critical driver of surface water heating, leading to thermal stratification, which affects the physical, chemical, and biological properties of the aquatic ecosystem. Data on heat fluxes, including net radiation, latent heat, and sensible heat fluxes, were collected and analyzed for both pre-monsoon and post-monsoon seasons. The results reveal significant spatial and temporal variability in heat fluxes along the river, with higher net radiation

Mechanistic insights into the photocatalytic and electrocatalytic activities of MgNiO2 : role of reactive oxygen species and oxygen vacancies

Granular MgNiO2 has emerged as a promising catalyst owing to its remarkable electrocatalytic activity and photodegradation efficiency under visible light. In this work, granular surface-engineered MgNiO2 nanoparticles were synthesized using the precipitation method. The interaction of Mg and Ni, forming Mg–Ni–O structures during high-temperature MgNiO2 synthesis, was investigated through X-ray photoelectron spectroscopy (XPS) analysis. The presence of Ni3+ species in the ionic form indicated charge transfer reactions in the catalyst. The band gaps of the as-prepared MgNiO2 and NiO were determined to be 2.2 eV and 3.7 eV, respectively. The first-order transverse optical (TO) phonon modes observed at 536 cm−1 indicated the presence of NiO, which was identified as the primary contributor to the Raman peaks. Further, the photocatalytic degradation of caffeine under visible light achieved a removal efficiency of 95.5% within 180 minutes. The intermediate reactive oxidative species (ROS) leading to MgNiO2 degradation were identified, and their lifetime and diffusion length in the solution were reported. Superoxide (O2−˙) and hydroxyl (˙OH) radicals were identified as the main ROS contributing to caffeine degradation. The electrocatalytic oxygen evolution reaction (OER) indicated a high density of oxygen vacancies in MgNiO2 compared to NiO, suggesting the promoter role of Mg species in the photocatalyst. These insights provide a holistic understanding of MgNiO2 as a catalyst and its pivotal role in green and efficient caffeine photodegradation and the electrocatalytic OE

Utilization of Indian low volatile medium coking coal for preparation of metallurgical coke

Coke is essential to the iron-making process, as the efficient function- ing of a blast furnace depends on the use of high-quality coke. However, India has limited reserves of prime coking coal, which is critical for producing such coke. The challenges associated with using high-ash Indian coal in coke production have led to increased reliance on imported coal, thereby escalating production costs and weakening the global competitiveness of the Indian steel industry. This dependency further lowers the energy efficiency of coke produc- tion due to the significant energy required for coal transportation. To address this limitation, the blending of Indian-origin low-volatile med- ium coking (LVMC) coal offers a promising approach to reduce depen- dence on high-grade coal while minimizing the impact on coke quality. In this study, three different Indian LVMC coals were blended with prime coking coal, and three distinct coke preparation methods were evaluated to optimize both blend proportions and processing techniques. The results indicate that up to 50% LVMC coal can be used in the blend while still achieving good coke properties, making this a viable strategy for sustainable coke production in the Indian steel industry

Attenuation characteristics of mechanical vibrations and its effect on heritage structures of Chittorgarh Fort Complex, India

The Chittorgarh Fort Complex (CFC), a ‘UNESCO World Heritage site’, is a protected ancient monument in India that has historical and cultural significance. A study to evaluate the critical impact of ground vibrations induced by Heavy Earth Moving Machineries (HEMM) operational in mines near CFC was carried out as per the directive of the Hon’ble Supreme Court of India. A comprehensive investigation has been carried out in different phases to analyze attenuation characteristics of ground vibrations induced by HEMM and its associated cumulative impact on the various structures of CFC. Various combinations of HEMM, such as surface miner and rock breaker (120 Ton), rock ripper, and high-capacity hydraulic excavator, etc., were made operational individually and cumulatively in the adjacent mines to measure the induced vibrations and frequency using advanced seismograms. Vibration monitoring was also carried out at various critical structures of CFC to assess likely damage due to amplification in the induced vibrations under different permutations and combinations of HEMM operations. The attenuation characteristics of observed vibration data in different experimental conditions have been analyzed and compared with the widely accepted vibration standards. The study signifies that vibrations induced by the HEMM do not have damage potential beyond 50 m, and this also holds true for the cumulative operation of the machines. In most cases, vibrations induced by individual machinery decay completely after travelling around 250 m distance, whereas vibrations travel up to a distance of 500 m in case of cumulative operation of different HEMMs. Empirical attenuation predictors are proposed for individual and/or collective HEMM operations, considering the intensity of the vibrations generated in the various experimental setups. The findings of the study on decay characteristics of mechanical vibrations may be used while planning for the deployment of such types of machinery near sensitive structures

A DFT study of the ternary metal chalcogenides (XAlS2) materials for photovoltaic and high-temperature applications

This work employs density functional theory (DFT) to investigate the structural, electronic, and optical properties of XAlS2 (X = Li, Na, K, Rb, and Cs) nanomaterials for potential use in photovoltaic applications. A comprehensive first-principles analysis has been conducted using GGA-PBE, GGA-PBEsol, and LDA functionals to examine LiAlS2, NaAlS2, KAlS2, RbAlS2, and CsAlS2. The findings reveal distinctive band gaps within this set of materials, with LiAlS2 and NaAlS2 exhibiting indirect band gaps and KAlS2, RbAlS2, and CsAlS2 possessing direct band gaps. Analyzing the partial density of states indicates that the valence band predominantly arises from S-3p and Al-3p orbitals, showcasing covalent bonding through hybridization. Furthermore, the examination of the optical properties of XAlS2 materials suggests their notable light absorption in the ultraviolet range, positioning them as promising candidates for photovoltaic applications. Additionally, the lattice thermal conductivity of two dynamically stable systems has been investigated and their thermoelectric properties have been calculated. Notably, a dimensionless figure of merit of 2.78 for LiAlS2 has been identified, marking it as a strong contender for high-temperature thermoelectric applications

Fluid Flow Analysis of a Mine Ventilation Axial Fan Using CFD Techniques

Ventilation is an essential component of underground mining, as it helps maintain the safety and health of miners. Consequently production and work efficiency can be enhanced. The principal purpose of the ventilation system is to regulate the quantity and quality of fresh air while eliminating hazardous gases. With the intention of increasing the energy efficacy of an axial flow fan, this study investigates the design aspects of mine ventilation fans. A three-dimensional model of the fan was developed based on the dimensions of the fan were estimated using a one-dimensional technique. A 3D model of an axial fan and a CFD analysis of its performance are investigated for underground mining ventilation application. Several cases have been studied, leading to the conclusion that the forced axial ventilation fan case, characterized by a Solidity value of 1.6, is deemed suitable for further investigation. The CFD analysis demonstrates that the forced axial flow mining fan has been designed to effectively discharge a volumetric flow rate of 47.13 m3/s of air, while operating at a rotational speed of 600 revolutions per minute. It achieves a significant static pressure rise of 838 Pascals across the rotor while consuming 48 kW of power

Elastic anisotropy and deformation characteristics of Pennsylvania anthracite

he mechanical behavior and elastic anisotropy of coal under stress are critical to understanding its structural integrity and performance in subsurface environments. Despite its significance, limited research has systematically analysed the elastic anisotropic responses of coals under such conditions. This study investigates the elastic anisotropy of three anthracite-rank coals, Primrose, Lattimer, and Mt. Carmel, subjected to conventional triaxial loading. P-wave (VP) and S-wave (VS) velocities, along with Thomsen parameters (ε and γ), were evaluated to elucidate the effects of increasing vertical stress on the structural integrity and anisotropy of each coal type. The results reveal that the Primrose coal exhibits the highest structural integrity, maintaining elevated VP and VS values and stable Thomsen parameters under stress due to its dense microstructure, higher inertinite content, and low porosity, which resist stress-induced microcracking. In contrast, the Lattimer coal demonstrates a significant reduction in VP and ε beyond 45 MPa, indicating greater susceptibility to microstructural damage and a trend towards isotropy as stress increases. The Mt. Carmel coal shows intermediate behavior, with moderate decreases in VP and ε but relatively stable γ values, reflecting a balanced resistance to structural degradation. S-wave anisotropy, as evidenced by shear wave splitting, remains most prominent in the Primrose coal, suggesting its superior ability to retain directional properties and resist stress-induced deformation. Principal component analysis highlights the role of rank, inertinite-to-vitrinite ratio, and aromaticity in influencing the mechanical responses of the coals, with Primrose coal consistently segregating as the most robust and anisotropically stable sample. These findings underscore the critical influence of compositional and microstructural differences on coal's anisotropic behavior under conventional-triaxial loading. They provide valuable insights for applications in subsurface energy extraction and storage, where understanding the mechanical and anisotropic properties of coal is essential for optimizing performance and mitigating risks

Pore structure evolution of Jharia coal for potential underground coal thermal treatment and associated CO2 sequestration

Underground coal thermal treatment (UCTT) is an emerging technique for clean energy extraction from coal, which also creates a unique CO2 sink environment in the form of pyrolytic char. In this study, a pathway for cleaner and efficient extraction of energy from coal is proposed. Early coalbed methane (CBM) extraction, application of UCTT followed by CO2 sequestration in pyrolytic char formed during UCTT presents an opportunity to maximize the utility of coal in new energy scenarios. To characterize Jharia coal in terms of its pore size distribution (PSD), pore surface area, pore volume, thermal evolution, CO2 adsorption attributes at low P/T (low-pressure and low-temperature), and surface morphology at different temperatures (30, 150, 300, 450, and 600 °C), a variety of analytical techniques such as low-pressure gas adsorption (LPGA), small angle X-ray scattering (SAXS), mercury intrusion porosimetry (MIP), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) were employed. The results show that the quantity of adsorbed CO2 (at low P/T) increased by 138 % for coal subjected to the maximum pyrolysis temperature of 600 °C. The PSD showed significant variations at different pyrolytic temperatures. While the pores did not show large variations when coal was heated up to 300 °C, the micropores increased sharply, while the mesopores and small macropores reduced when heated further. The elevated pyrolytic temperatures resulted in the enlargement and merging of mesopores and small macropores, along with the formation of new pores due to thermal decomposition and release of volatiles. Consequently, this contributed to a significant increase in the volume of macropores, and overall porosity. The increase in the accessibility of pores under the UCTT environment could significantly boost the CO2 storage capacity in coal

Modification of Functional Groups and Stacking Structure of Some Indian Non-Coking Coals During Pyrolysis

Changes in stacking structure and the functional groups of three non-coking coals during pyrolysis have been carried out using X-ray diffraction (XRD) and Fourier-Transform Infrared Spectroscopy (FTIR). The interlayer spacing of the stacking structure changed from 3.44 to 3.66 Å, 3.49 to 3.68 Å, and 3.60 to 3.72 Å and aromaticity changed from 0.64 to 0.70, 0.63 to 0.74, and 0.68 to 0.78 due to pyrolysis of the samples AMD, BMD and JMD respectively. The rank parameters also change from 1.80 to 2.29, 1.72 to 2.36, and 1.61 to 3.49 for the same coals in similar order. It is observed that the interlayer spacing, aromaticity and rank of coal increase with the increase in temperature. The FTIR results show that the functional group associated with minerals increases while the functional groups associated with coal macerals like methyl group, C=C aromatic, and oxygen-containing functional groups decrease due to pyrolysis. The FTIR structural parameters such as the ratio of aliphatic to the total atomic hydrogen, and the ratio of carbonyl to aromatic groups decrease with the increase in temperature while aromaticity, degree of condensation of aromatic rings, and the ratio of aliphatic to aromatic carbon increase with the increase in temperature up to 600°C. The sudden changes in FTIR structural parameters of coals are observed at 800°C. The present study shows that with increasing temperature, the aromatization and degree of condensation of aromatic rings of coal increase with the removal of aliphatic side chains and reduction in oxygen-containing functional groups

Integration of fluid-invasive, scattering, and imaging methods in resolving pore structures in coal and shale

In this study, coal and shale samples were collected from the gas-rich Barakar Formations and investigated using various analytical and imaging methods, to quantify their pore attributes. The results indicate that coal contains an abundance of nanopores that occur in clusters, along with evidence of microfractures in its structure, as observed through scanning electron microscopy (SEM). The accessible micropore surface area (SA) of coal samples is around 2.5 times higher than that of shale samples, while the total mesopore SA in coal is around half that of shales. However, the average pore width of coal samples is approximately 0.82 times that of shale samples. These findings suggest that a higher percentage of organic carbon in coal contributes to an abundance of organic pores, which results in greater porosity in coal samples when compared to shale. The total SA determined by gas adsorption for the entire spectrum of pore sizes in coal is around two times that of shale. Interestingly, despite the difference in the pore SA and the pore volume, the pore surface roughness in the studied coals is almost equal to or slightly higher than that of shales. The study observations show that the total organic carbon and mineral composition in coal and shale play little influence on the degree of pore connectivity. The degree of pore connectivity for the coal samples varies from 0.4–0.93, whereas for shale samples it ranges from 0.50–0.82. This study provides analytical insights into the pore structure of coal and shale collected from the same reservoir by considering factors such as depth, mineralogical content, and surface roughness. During CO2 injection, coal and shale reservoirs may experience swelling induced stress changes, potentially impacting their mechanical stability. Thus, this study provides insight into estimating the gas-storage capacities of both coal and shale reservoirs and aims to optimise the gas adsorption and maintain structural integrity. This approach ensures the long-term feasibility of implementing Enhanced Coalbed Methane (ECBM) recovery and shale gas recovery in other gas basins