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Extracting gas from unconventional shale reservoirs with low permeability is challenging. To overcome this, hydraulic fracturing (HF) is employed. Despite enhancing shale gas production, HF has drawbacks like groundwater pollution and induced earthquakes. Such issues highlight the need for ongoing exploration of novel shale gas extraction methods such as in situ heating through combustion or pyrolysis to mitigate operational and environmental concerns. In this study, thermally immature shales of contrasting organic richness from Rajmahal Basin of India were heated to different temperatures (pyrolysis at 350, 500 and 650 °C) to assess the temperature protocols necessary for hydrocarbon liberation and investigate the evolution of pore structural facets with implications for CO2 sequestration in underground thermally treated shale horizons. Our results from low-pressure N2 adsorption reveal reduced adsorption capacity in the shale splits treated at 350 and 500 ºC, which can be attributed to structural reworking of the organic matter within the samples leading to formation of complex pore structures that limits the access of nitrogen at low experimental temperatures. Consequently, for both the studied samples BET SSA decreased by ∼58% and 72% at 350 °C, and ∼67% and 68% at 500 °C, whereas average pore diameter increased by ∼45% and 91% at 350 °C, and ∼100% and 94% at 500 °C compared to their untreated counterparts. CO2 adsorption results, unlike N2, revealed a pronounced rise in micropore properties (surface area and volume) at 500 and 650 ºC (∼30%–35% and ∼41%–63%, respectively for both samples), contradicting the N2 adsorption outcomes. Scanning electron microscope (SEM) images complemented the findings, showing pore structures evolving from microcracks to collapsed pores with increasing thermal treatment. Analysis of the SEM images of both samples revealed a notable increase in average pore width (short axis): by ∼4 and 10 times at 350 °C, ∼5 and 12 times at 500 °C, and ∼10 and 28 times at 650 °C compared to the untreated samples. Rock-Eval analysis demonstrated the liberation of almost all pyrolyzable kerogen components in the shales heated to 650 °C. Additionally, the maximum micropore capacity, identified from CO2 gas adsorption analysis, indicated 650 °C as the ideal temperature for in situ conversion and CO2 sequestration. Nevertheless, project viability hinges on assessing other relevant aspects of shale gas development such as geomechanical stability and supercritical CO2 interactions in addition to thermal treatment. Highlights: Insitu thermal treatment of shales for liberation of hydrocarbons and CO2 sequestration. Significant changes in shale geochemistry and pore properties with increasing temperatures of treatment. Visualizing thermally induced pore evolution in shale: microcracks to collapsed pores. Limitations of N2 in accessing complex pore structures. [ABSTRACT FROM AUTHOR]

Microplastic has emerged as a global threat owing to its chronic ubiquity and persistence. Microplastics' small size expedites their ingestion at each trophic level causing biomagnification and bioaccumulation, which has raised public concerns. The present study isolated, quantified and characterized the abundance, shape, size, color, and chemical composition of the microplastics from water and sediments of the Hirakud Reservoir through a scanning electron microscope and FTIR. The ecological risk associated with the microplastics was assessed using the species sensitivity distribution (SSD) method to derive the Predicted No-Effect Concentration (PNEC) value and risk quotient (RQ). The abundance of microplastics in the surface water and sediments of the Hirakud Reservoir was estimated at 82-89 particles/L and 159-163 particles/kg, respectively. Fiber-shaped microplastics dominated both surface water (46.21%) and sediment samples (44.86%). Small-sized microplastics (53-300 μm) prevailed in all samples. Color delineation exhibited an abundance of transparent microplastics. Chemical characterization indicated the dominance of polypropylene (38%), followed by high-density polyethylene, low-density polyethylene, and polystyrene. The calculated PNEC value was 3,954 particles/m³, and the RQ was estimated to be 0.02073-0.04122 indicating negligible ecological risk to freshwater species in all the sampling sites. [ABSTRACT FROM AUTHOR]

Introduction: Anterior composite restorations present many aesthetic challenges for clinicians. Direct veneers provide chairside advantages such as evaluating tooth anatomy, shade selection, and correcting tooth morphology according to the patient's desire. In today's world, the use of digitalisation and 3D-printed models has grown. However, limitations of these are unknown and a research gap exists, with surface roughness being a major issue. Aim: To evaluate the surface roughness of clear silicon templates fabricated over 3D-printed models, blue inlay wax and dental stone. Materials and Methods: This in-vitro study utilised both quantitative and qualitative approaches. The study was conducted at the Department of Conservative Dentistry and Endodontics, Manubhai Patel Dental College and Hospital, Vadodara, Gujarat, India. The study was completed over three months. A total of 36 surfaces of clear silicone template (Exaclear) were obtained from two blocks each of 3D-printed model, blue inlay wax, and dental stone, measuring 30Ã--10Ã--10 mm. These blocks were divided into six units of 10Ã--5 mm (N=36) and were divided into three groups: 1) 3D-printed model; 2) Blue inlay wax; 3) Dental stone. Surface roughness was evaluated using a surface roughness tester and Scanning Electron Microscope (SEM). Quantitative analysis of surface roughness was done using the surface roughness tester, and qualitative analysis was done using SEM. Statistical analysis was done using the posthoc Tukey Honest Significant Difference (HSD) test and statistical software SPSS Version 20.0. Results: The quantitative analysis showed the highest Roughness average (Ra) value mean±Standard Deviation (SD) for Group 1 (11.97±4.43 μm), followed by Group 3 (2.42±1.07 μm) and Group 2 (0.63±0.86 μm). SEM showed the presence of voids only in Group 1. Conclusion: Surface roughness of clear silicon template fabricated on wax surface is less as compared to templates fabricated on 3-D printed models. [ABSTRACT FROM AUTHOR]