Search Results (567)

The lower Messinian Calcare di Rosignano Formation (Tuscany, Italy, 43° N) preserves one of the youngest and northernmost examples of coral reefs in the Mediterranean. The outcropping succession of the Acquabona quarry consists of four main facies, namely, in ascending stratigraphic order: (1) coral boundstone, (2) coralline algal rudstone, (3) serpulid floatstone to packstone, and (4) peloidal packstone to grainstone. The succession displays a trend toward increasingly more shallow conditions and progressively more restricted water circulation. The coral reef displays a limited coral biodiversity and a remarkable abundance of heterotrophs, similar to modern coral reefs developed at the edges of the ecological niche of symbiont-bearing colonial corals. The widespread presence of coral colonies pervasively encrusted by coralline algae and benthic foraminifera suggests that short-term environmental perturbations caused temporary shutdowns of the coral-dominated carbonate factory. Moving upwards, there are fewer corals and more highly adaptable carbonate producers like coralline algae and serpulids. This suggests that the decline of corals had been caused by the conditions in the basin becoming more stressful, up to the collapse of the coral community. The overall succession indicates that coral-dominated ecosystems located at the edges of the coral zone are very sensitive; they can be affected even by minor perturbations and easily collapse if negative conditions persist. Full article

Bracara Augusta (Braga, Portugal), one of the most important cities of the NW Iberian Peninsula, was founded by the emperor Augustus approximately between the years 16/15 BC. Throughout the Roman period, it has undergone various monumentalisation programmes according to its status, the first one as a convent capital and a later one as a provincial capital. The investigation of the economic cost of construction in the ancient world allows us to understand Roman architecture and the society of builders, both from economic and social perspectives. In recent years, based on the works of Janet DeLaine and Paolo Barresi, despite the large number of variables and the difficulty of quantifying them, a calculation methodology has been developed to approximate the cost of architecture, based on the information contained in two main documents: the Diocletian’s Edict of Prices (301 AD) and the nineteenth-century architecture and engineering manuals summarised by Pegoretti. Our goal is to understand part of the construction process of Roman architecture in the NW Iberian Peninsula, considering the cost of raw materials, namely stone, and the labour required in its preparation and utilisation. In this study, we present a cost proposal associated with the monumentalisation of two of the city’s important buildings: the forum’s large buildings and the theatre. The construction of the city was made fundamentally using local stone, from different quarries, endowing it with notable buildings and requiring a strong contribution from the local elites. Full article

Very large quantities of stone waste sludge are disposed in exhausted quarries and have a very low reuse rate to date. The paper considers the possibility of using these types of industrial waste in partial substitution of natural aggregates for the production of lime-based plasters. Traditional materials based on lime, the only material with a carbon neutrality life cycle, have considerable potential for use as components of green materials for plastering and finishing building surfaces in both new construction and historic heritage conservation. The paper presents the preliminary results of a research activity aimed at developing pre-packaged products based on Traditional Lime Putty (TLP) by partially replacing natural aggregates with Stone Waste Sludge (SWS), with a low rate of recovery from the Apricena limestone production district in Apulia. The mineralogical and chemical analysis carried out using XRD (X-Ray Diffraction), TG-DTA (Thermo Gravimetry-Differential Thermal Analysis), and hydrochloric acid attack test showed that the SWS consisted of 98.4 % CaCO₃ by mass. The particle sizes measured by laser diffraction technique are below 22.5 μm for the 92% mass of the sample. The high fineness of the stone waste was confirmed by the Blaine-specific surface method, which equals to 9273.79 cm²/gr. The behavior of three fresh mixtures for prepacked coarse plaster, fine plaster, and finishing plaster with 12.90%, 17.94%, and 18.90 by mass of SWS, respectively, was evaluated by spreading test and applicability tests on a perforated ceramic slab. The finishing plaster has the highest consistency value of 235 mm, while the fine plaster and the coarse plaster have values of 205 mm and 155 mm, respectively. The coarse plaster is suitable for use as base plaster (arriccio) or second layer rendering (tonachino) up to a thickness of approximately 1 cm. Both the fine plaster and finishing plasters can be used for the surfaces finishing with the application of layers of a few millimeters thick. Full article

Background: Pneumococcal disease (PD) is a major cause of morbidity and mortality in young children in Asia and globally. Pneumococcal conjugate vaccines (PCVs) have significantly reduced the burden of PD when included in pediatric national immunization programs (NIPs). This study estimates the clinical and economic burden of PD due to serotypes contained in different PCVs in children aged < 5 years in eight Asian countries/territories. Methods: Based on published data, a cohort-based decision analytic model was used to estimate annual PD cases, deaths, and direct medical costs associated with serotypes contained in PCV10, PCV13, PCV15, and PCV20. Results: PD incidence rates were lower in regions with PCV13 in their NIP than those without. Serotypes contained in higher but not lower valency PCVs resulted in a significant incremental clinical and economic burden, although the difference between PCV13 and PCV15 serotypes was generally small. Moving from PCV13 to PCV20 was estimated to result in greater clinical and economic burden reductions. Conclusions: This study demonstrates the remaining and incremental burden of PD from PCV10 to PCV20 serotypes in young children in selected Asian regions. Extending NIP access to higher-valency PCVs with broader serotype coverage and improving vaccine uptake will help prevent morbidity and deaths and save healthcare costs. Full article

In addition to the surrounding climatic environment, the intrinsic characteristics of the stones used in construction are a critical factor to understand a building’s conservation state and define the necessary planning and conservation management activities. The use of environmentally susceptible stones, such as carbonate stones, in heritage buildings can be especially problematic. The present investigation presents an overview of past research and contributes to identifying the types of carbonate stones used over time in Coimbra’s Old Cathedral in Portugal, which was classified as a National Monument and integrated into the Coimbra World Heritage site by UNESCO. Our mineralogical and chemical analyses revealed the use of carbonate stones from different quarries (Coimbra region), including Ançã limestone and dolostone (Porta Especiosa portal), Portunhos limestone and Outil limestone (in the perimeter of windows), and marlstones and Outil limestone (side facades). These stones, which were installed at various times during the construction and alteration of the monument, represent a great challenge for conservation planning due to their intrinsic vulnerability to adverse environmental conditions and pollution. Full article

In this study, by using the texts describing the hazards and precautions taken during text mining, the necessary processes were carried out to first estimate the probability value and severity value of the risk and then calculate the risk values by Natural Language Processing analysis. In order to be used within the scope of the study, two data sets were generated from the data in the risk assessment report prepared by applying the L-type matrix risk assessment in marble quarries between 2015 and 2021. Stochastic Gradient Descent (SGD) was used for classification and prediction by analyzing text data. One data set was used to analyze the probability value of the risk and the other was used to analyze the severity value of the risk. In light of the results, when a text containing hazard and precaution information was entered, a system was developed that analyzed this text, estimated the probability and severity values, and calculated the risk assessment score. The application of the SGD algorithm to learning models developed on text data yielded an accuracy rate of 91.2% in the risk probability data set and 97.5% in the risk severity data set. The results indicated that the models were capable of conducting automatic risk assessment on text data and of effectively predicting the requisite probability and severity values. Due to the high accuracy rates obtained during the study, this risk assessment software was recommended for use in marble quarries. Full article

The valorisation of sludges from aggregate production into construction materials is required for full circularity in mining waste management. This study explores valorisation pathways, relevant regulatory frameworks, and End-of-Waste (EoW) criteria for specific settings in Spain and Norway. The explored valorisation routes involved the production of filler, supplementary cementitious materials (SCMs), and lightweight aggregates (LWAs) for the production of cement-based products, and precursors for 3D printed construction material. The sludge from Norway revealed a non-polluted stream and a stream contaminated with organic phases and clays. Sludge-based filler proved suitable in concrete production with contents of up to 40% of total binder, providing adequate consistency and cohesion. However, clays in the sludge increased the demand for water and superplasticizer. Clay contents were still insufficient for the applications as SCMs, as the calcined sludge demonstrated limited reactivity. The application to produce LWAs was promising, but further microstructure optimization is still required. The clay content was also relevant for the sludge from the site in Spain, as it provided 3D printing mixes with good plasticity. The dosage optimization still required the addition of enzymes, limestone, and natural fibres to improve cohesion, workability, and resistance to the cracking of the 3D printing mix. Full article

Harsh winters, aging infrastructure, and the demand for modern amenities are major factors contributing to the deteriorating air quality in Bishkek. The city meets its winter heating energy needs through coal combustion at the central heating plant, heat-only boilers, and in situ heating equipment, while diesel and petrol fuel its transportation. Additional pollution sources include 30 km² of industrial area, 16 large open combustion brick kilns, a vehicle fleet with an average age of more than 10 years, 7.5 km² of quarries, and a landfill. The annual PM_2.5 emission load for the airshed is approximately 5500 tons, resulting in an annual average concentration of 48 μg/m³. Wintertime daily averages range from 200 to 300 μg/m³. The meteorological and pollution modeling was conducted using a WRF–CAMx system to evaluate PM_2.5 source contributions and to support scenario analysis. Proposed emissions management policies include shifting to clean fuels like gas and electricity for heating, restricting secondhand vehicle imports while promoting newer standard vehicles, enhancing public transport with newer buses, doubling waste collection efficiency, improving landfill management, encouraging greening, and maintaining road infrastructure to control dust emissions. Implementing these measures is expected to reduce PM_2.5 levels by 50–70% in the mid- to long-term. A comprehensive plan for Bishkek should expand the ambient monitoring network with reference-grade and low-cost sensors to track air quality management progress and enhance public awareness. Full article

In coal seam groups where the spacing between the upper and lower seams is small, the lower seam working face is significantly influenced by residual coal pillars from the upper seam and the void spaces created during mining. This presents considerable challenges for underground mining safety. Through field investigations, the layout of the coal seam quarry above the working face of the 3⁻¹ coal seam in Yanghuopan Mine was examined, along with the distribution of the residual coal pillars. This allowed for the identification of the interlayer rock strata characteristics. Subsequently, we analyzed the mechanism of directional hydraulic fracturing and decompression to determine the key parameters of the 3⁻¹ coal seam. Using the Rock Fracture Process Analysis 3D (RFPA 3D) numerical simulation, we evaluated the effects of various factors on the initiation and propagation of hydraulic fracturing-induced cracks, formulated the evolution law of these fractures, and incorporated the damage variables into the analysis. Additionally, we assessed the influence of different parameters on crack initiation and extension during hydraulic fracturing, using RFPA 3D simulations to derive the evolution law governing directional hydraulic fractures. This allowed us to define the hydraulic fracturing parameters for the 3⁻¹ interbedded rock layers by integrating the process parameter calculations with the damage variables. Based on these findings, an on-site implementation plan was developed and executed, followed by a comprehensive evaluation of the construction results. The study concludes that directional hydraulic fracturing and decompression effectively contribute to the prevention and control of roof-related disasters in the mining of lower coal seams where seam spacing is minimal. This research offers valuable theoretical insights and practical reference for disaster prevention and control in similar geological conditions. Full article

This paper presents the results of precise measurements of temperature and pore pressure in the “reservoir–well” system during the development of iron ore deposits of the Kursk Magnetic Anomaly (KMA) via blasting. For the observation period from October 2021 to June 2024, variations in compressibility, permeability and temperature in the upper Albian-Cenomanian confined aquifer, which is used for district water supply, were determined. The general trend in a decrease in water temperature was traced (from 12 °C to 11.4 °C). It was accompanied by an increase in the hydrostatic head (from 3.7 m to 7.4 m). Water temperature in the upper aquifer was measured for 9 industrial explosions in the mine and for 30 explosions in the quarry. For one explosion in the mine and five explosions in the quarry the coseismic changes in water temperature with amplitudes of 0.06–0.09 °C were established, while changes in pore pressure in the “reservoir–well” system were 0.4–2.2 kPa. Local changes in the permeability of the reservoir in the vicinity of the well (the skin effect) are considered to be the main factor that controls the coseismic response of temperature during industrial explosions. As the reservoir permeability increases, the water temperature in the “reservoir–well” system can decrease and vice versa. The same pattern was observed according to regime measurements performed in 2022–2023. The recorded coseismic responses of water temperature in the upper aquifer in the high-frequency range are similar to the effects observed during propagation of seismic waves originated from earthquakes in the low-frequency range at different sites all over the world for the seismic energy density of 0.05–0.45 J/m³. The observed variations in aquifer temperature in the “reservoir–well” system under episodic dynamic impacts are of particular interest from the point of view of activating hydrogeochemical processes that accompany the development of iron ore deposits. Full article

In this study, the feasibility of using ceramic wastes in the production of blended cement was evaluated by substituting limestone with ceramic waste at the percentages of 5, 10, 15, 20, and 28% before the milling stage. The chemical, physical, and mechanical properties of the cements were determined according to relevant standards, and the results were compared. The chemical analysis showed that the SiO₂ content of the cements increased with higher ceramic waste substitution percentages, while the CaCO₃ content decreased. The grindability of cements decreased with increased ceramic waste ratios, slightly reducing the Blaine specific surface area values. The water consistency for the cements was set at 28%, and all the cements met the standard limitations. The spread diameters for all types of cements were similar and practically usable in terms of workability. The cements containing ceramic waste either maintained or extended the setting time. All cements with ceramic waste exhibited higher flexural and compressive strength compared to the reference cement. The highest flexural strengths were achieved with a 28% ceramic waste substitution ratio across all curing ages. Regarding compressive strengths, all cements exhibited higher compressive strength than 10 MPa at 2 days and 32.5 MPa at 28 days, classifying them as 32.5 R-type blended cements. When the medium- (56–90 days) and long-term (365 days) compressive strengths were compared, the highest strength values were obtained from the cement with a 28% ceramic waste substitution. Although limestone-blended cement is emerging as a promising alternative to traditional Portland cement, these types of cement still contribute to environmental degradation due to the extraction of natural limestone resources through quarrying. This study showed that blended cements can be produced using ceramic waste, providing a more sustainable and environmentally friendly solution for the construction industry. Full article

The paper is about community-based participatory research on environmental conflicts about sand quarries in northern Bogotá. Community-based participatory research is applied to understand the environmental conflicts of mining activities. The approach was suitable for improving the relevance and acceptance of research in the local community. It invited community members to participate and uphold their views about the social conflicts and environmental impacts arising from mining activities. The findings highlight the need for participatory environmental governance, integrating local communities and power relations analysis in environmental decision-making. Full article

Cone crushers have a central role in the processing of quarry rocks, besides coarser ore preparation in several mineral processing plants. This is particularly true in the case of Itabirite iron ore preparation plants in Brazil, so optimizing their performance is of central importance for reaching maximum productivity of the circuit. The work presents results of modeling the HP500 cone crusher in operation in an industrial plant in Brazil (Minas Rio), from surveys carried out over a few years with different feeds and crushing conditions. A version of the Andersen–Whiten cone crusher model was implemented in the Integrated Extraction Simulator featuring a non-normalizable breakage response and a fit-for-purpose throughput model. The results demonstrate the good ability of the model to predict crusher performance when dealing with different closed-side settings and feed size distributions. Full article

The sourcing of raw materials is becoming an increasingly concerning issue for the European Union, which is adopting a series of strategies aimed at mitigating the dependence on third countries for procurement. The supply of feldspars, for instance, which is significant within the ceramic industry, raises concerns due to heavy reliance on third countries. Therefore, it is imperative to identify potential alternative sources for procurement, including the recycling of waste from the extraction of ornamental granite rocks enriched in such minerals. The Sardinia region in Italy, once a global leader in granite extraction, has now witnessed a significant reduction in production due to intense competition worldwide, resulting in severe economic repercussions. Additionally, traces of this period remain in the territory in the form of enormous quantities of extraction waste, defacing the landscape and posing potential environmental issues. This study is part of a broader research initiative aimed at identifying a physical process to concentrate rare earth element (REE) minerals from granite waste in a quarry located in Buddusò, Sardinia. The specific objective of this study is to analyze the whole rock composition, crushing powder, and the diamagnetic by-products generated by gravity and magnetic separations to identify potential applications for their use. Full article

This research addresses a critical gap in understanding the environmental impact of natural rock aggregate production in Sri Lanka. The study employs life cycle assessment (LCA) and SimaPro Software to simulate natural coarse aggregates’ extraction and manufacture process. Key findings reveal significant environmental impacts, with human carcinogenic toxicity (2.45938 × 10⁻⁶ Pt), eutrophication of freshwater (1.59326 × 10⁻⁶ Pt), and fossil resource scarcity (1.4823 × 10⁻⁶ Pt) being significant concerns. The crushing process in particular shows the highest levels, contributing 2.21 × 10⁶ to human carcinogenic toxicity and 8.92 × 10⁷ to freshwater eutrophication. High electricity consumption, particularly from hard coal in electricity generation, is identified as a primary contributor. Although the sole source of coarse aggregate production in Sri Lanka is natural rock crushing, there is a lack of country-specific environmental impact assessment data for this process. This study provides a valuable dataset for the Sri Lankan construction industry, covering various environmental impact categories and encompassing the sub-processes inherent to natural rock aggregate production. The research highlights the necessity of implementing sustainable practices in quarry operations, proposing a transition towards more environmentally friendly energy sources. By quantifying environmental effects, this study provides valuable insights for stakeholders in the construction sector, enabling informed decision-making and targeted interventions to enhance overall sustainability while offering aggregate manufacturers opportunities to adopt more sustainable practices. Full article