Gold (Au) and silver (Ag) are commonly co-extracted from low-sulphidation epithermal (LSE) ores by alkaline cyanidation, yet their dissolution behaviors often diverge despite close mineralogical association. This study investigates Au–Ag cyanidation in ore from the Mount Muro LSE deposit, Central Kalimantan, Indonesia, through integrated mineralogical characterization, diagnostic leaching, time-resolved cyanidation, residue analysis, and kinetic modeling. Diagnostic leaching indicates that ~80% of Au is cyanide-accessible at P₈₀ ≈ 75 μm, whereas only ~54% of Ag occurs in free-milling domains, with the remainder hosted in sulfide and Cu–Ag sulfosalt phases. Continuous cyanidation confirms this contrast: Au dissolves rapidly and reaches a plateau of ~87% recovery, while Ag extraction proceeds more gradually to ~78%. Residue analysis shows that unrecovered Au and Ag are concentrated in fine fractions (<38 μm), demonstrating control by mineralogical locking, partial passivation, and micro-scale diffusional barriers rather than reagent insufficiency. Shrinking Core Model diagnosis identifies mixed kinetic control for Au and diffusion-dominated control for Ag. Despite differing dominant mechanisms, kinetic model discrimination shows that both metals are best described by the Ling model, capturing non-linear, accessibility-controlled dissolution. These results highlight evolving surface accessibility as the primary control on cyanidation performance in mildly refractory LSE ores.
Heavy metal(loid)s (HMs) represent significant environmental and health threats due to their persistence, bioaccumulation, and ability to induce oxidative stress and lipid peroxidation (LPO) in aquatic organisms. Here, we present the first lipidome analysis of the mud crab Scylla paramamosain to examine associations between lipid profiles and 12 HMs across three contaminated estuaries in Guangdong Province. We observed pronounced sex-specific differences in both HMs concentrations and lipid composition (P < 0.05). The lipidome showed marked dysregulation of membrane lipids, with glycerophospholipids (52.33%) and sphingolipids (11.9%) predominating, alongside elevated energy-storage lipids such as triacylglycerols (24.35%). Major glycerophospholipid classes included phosphatidylcholines (7.7%), phosphatidylethanolamine (7.49%), phosphatidylserine (6.98%), and phosphatidylglycerol (5.31%), while within the sphingolipid fraction, carnitines (4.43%) and ceramides (>2.26%) were abundant, and saccharolipids such as MGDG were present at low levels (0.07%). Female crabs exhibited significantly higher HMs concentrations and lipid levels than males, with copper (Cu), iron (Fe), and zinc (Zn) being the most abundant. Notably, Cu, Fe, and lead (Pb) showed strong positive correlations with all lipid groups. The associated lipid alterations are consistent with mitochondrial dysfunction and oxidative stress-related pathways commonly linked to HMs exposure. Although sex- and site-specific differences cannot be attributed exclusively to HMs under field conditions. These findings demonstrate the sensitivity of lipidomic profiles to environmental contamination and highlight lipidomics as a powerful tool for assessing ecological risks in HM-contaminated estuarine systems.
Intertidal vegetation plays an essential role in habitat provision for waterbirds but suffers great losses due to human activities. However, it is challenging in tracking the human-driven loss and degradation of intertidal vegetation due to rapid urbanization in a high temporal resolution. In this study, a methodological framework based on full Landsat time-series (FLTS) is proposed to detect the year of change (YOC) of intertidal vegetation converted to impervious surfaces (ISs) and artificial ponds (APs), and the condition of the remaining intertidal vegetation was also assessed by FLTS, in the Fujian province, a subtropical coastal area lying in southeast China. The accuracies of the YOC detection of intertidal vegetation converted to IS and AP were 91.84% and 72.73%, with mean absolute errors of 0.26 and 1.06, respectively. The total areas of intertidal vegetation encroached by IS and AP were 31.68 km2 and 23.85 km2, respectively. Most ISs were developed later than 2010, and most APs were developed earlier than 2005, which are highly related to the implementation of local policies for economic development. The remaining intertidal vegetation in growing, stable, and degraded conditions were 43.05%, 56.38%, and 0.57%, respectively. The results indicated that areas of intertidal vegetation were reclaimed for anthropogenic uses at a considerable rate, although the intertidal vegetation still increased owing to natural development after the establishment of natural reserves. The study demonstrates that the FLTS has capacities in monitoring the dynamics in coastal zones solely for its dense earth observations.
Coordinating and managing teams searching for missing persons in wilderness areas is challenging. Local terrain characteristics and environmental conditions strongly influence how searchers accomplish their search tasks. When making decisions, searchers consult various maps of the area. In this paper we proposed a methodology for mapping characteristics of the area that influence user behavior when walking the area, and define a walkability model of the terrain. We define walkability as a measure of how fast a person can walk through terrain. The observed walking speed depends on factors such as the fitness and motivation of a person walking through the terrain, as well as on assistive features and the configuration of the terrain. In our method, walkability is predicted only as a feature of terrain configuration. We used singular value decomposition (SVD) to transform datasets to extract latent features of the terrain and users from multiple Global Positioning System (GPS) trails. We define the walkability measure as a latent component of walking speed, which is a function of terrain features. Finally, we use a polynomial regression algorithm to build a model for predicting terrain walkability based on remote sensing imagery from the Sentinel-2 mission. The application of the proposed model is demonstrated in the Kozjak mountain region in the Republic of Croatia.
Dinh Van Duy, Hitoshi Tanaka, Magnus Larson
et al.
Analytical solutions for a one-line model for shoreline changes are employed to investigate the formation of two wave-dominated river delta coastlines, along with a small-scale laboratory experiment. Since the present analytical solution can be applied only to a river delta with infinite shorelines, a new analytical solution was developed to consider the effects of lateral boundaries to the evolution of delta coastlines. It was determined that two demarcations represented by the dimensionless times <i>t*</i> can be used to judge whether the lateral boundaries have affected the coastline evolution or not. After the successful application of a new analytical solution to the experimental data, the new analytical solution was applied to predict the formation and deformation of the shorelines of the Ombrone River and Funatsu River deltas. Results obtained from the analysis showed that the new analytical solution can be used to describe well the formation and deformation of finite river-delta shorelines. Based on the two demarcations as represented by the dimensionless time <i>t*</i>, the shorelines of the Ombrone River and Funatsu River deltas are classified as finite shorelines.
Nurlisa GINTING, Vinky N. RAHMAN, Achmad D. NASUTION
et al.
Bakkara is a village with tourism potential in Geoarea Sibandang, Toba Caldera Geopark, one of UNESCO Global
Geopark. This research was conducted to examine and review the geotourism development in Bakkara tourist destinations.
Furthermore, the output of this research is to preserve the value of geotourism such as conservation, education, economy, and
promotion, especially in public facilities. The method used in this study is a qualitative method through observation and focus
group discussion. The results show that public facilities in the development of geotourism have been implemented but have
not significantly affected tourism, and require some improvements.
The ambient and indoor air concentrations of PM10 and PM10-bound PAHs (16 priority PAHs) were investigated in Rayong Province, Thailand. The locations of the selected study areas were Map Ta Phut Industrial Estate and its vicinity comprising six sampling sites (four industrial areas and two vicinity areas). The indoor and ambient air samples of were collected in March 2017. The sampling sites located close to the road were detected the greatest ambient average concentrations of PM10, with an average value of 56.06 µg m-3 (Map Chalut Area or MC). The levels of indoor PM10 were mostly dependent on the resident activities and the highest mean level of PM10 was 31.29 µg m-3 detected at Huai Pong. The Benzo(b)fluoranthene and acenaphthylene were the major PAHs found to have the highest 24-h average concentrations for both indoor and ambient air. The highest mean ambient and indoor air levels of benzo(b)fluoranthene were 49.18 and 30.88 ng m-3, respectively, found at MC. In terms of 16 total PAHs, MC was found to have the greatest level. Analysis of the diagnostic ratios determined that the traffic density was the major source of influence on particle-bound PAH concentrations for both ambient and indoor air samples, which indicated that the greater the traffic volume, the higher the level of PAHs.
Smirnov Valery, Semenov Vladislav, Zakharova Anna
et al.
The article analyzes the current state of the Russian economy in the context of globalization. The research reveals the dominant role of capitalist countries in the process of globalization. The role of developing countries is related to ensuring a balanced world economy. Globalization causes changes in world economic relations. Russia has taken an active position not only among developing but also developed countries. The article reveals that in the context of the US trade war with China and increased protectionism, developing countries have assumed the risks of losing capital and falling into a deeper and longer recession. Russia’s position in economic globalization is linked to the place of BRICS in modern world order. Modern world order requires Russia to initiate the creation of new geopolitical communities, in addition to BRICS. To maintain Russia’s stable position in the world economy, modern objective reality requires not only its participation in various geopolitical communities,but also their initiation.
Low-frequency loop–loop electromagnetic induction (EMI) offers several key advantages over many other geophysical techniques for proximal soil sensing. Yet, because of problems with the inversion of measured apparent electrical conductivity (EC) data, application of EMI for geophysical imaging and interpretation is limited. In this study, a Bayesian inference was used to obtain electromagnetic conductivity images (EMCIs) from multiconfiguration EC data. This approach allows analysis of highly nonlinear problems and renders an ensemble of models obtained from the posterior distribution that can be used to explore parameter uncertainty. In this respect, generalized formal likelihood function was used to more accurately describe the sensitivity of the posterior distribution to residual assumptions. Discrete cosine transform (DCT) was employed as a model compression technique to reduce the number of unknown parameters in the inversion. The DCT parameterization was performed using training image (TI)-based geostatistical simulations considering the EC data pseudosection as a TI. The potential of the proposed approach was examined through different theoretical scenarios. The estimated subsurface EMCI shows excellent agreement with the original synthetic models subject to the appropriate choice of prior information. Moreover, DCT parameterization reduces the number of unknown parameters, increasing accuracy of the inversion with the Bayesian procedure. The proposed approach ensures accurate and high-resolution characterization of subsurface conductivity layering from measured EC values.
This paper analyzes the joint cost structure of electricity and natural gas distribution investments. Assessing the joint costs is critical for urban development and public policy regarding competition at the local level. The paper accounts for the urban and geographic factors at the local level, while the previous literature primarily used company-level data with a few or no site-specific variables in joint cost analyses. An empirical analysis of the multi-utility capital costs suggests that the local urban and geographic conditions affect such costs, with economies of scope present in electricity and natural gas both in terms of total costs and underground investment costs. Hence, the joint service provision makes economic and environmental sense for urban policy makers.
Geography. Anthropology. Recreation, Social Sciences
El presente trabajo de investigación muestra que para la construcción de una línea de transmisión de 220 kv. Cajamarca – Carhuamayo se emitió a la atmósfera 4025 toneladas de CO2 equivalentes lo que nos lleva a pensar que toda actividad es responsable por la emisión de gases de efecto invernadero a la atmósfera que llevará al Calentamiento Global para posterior a ello llevarnos al Cambio Climático.
El trabajo se realizó en base a 2 alcances; el alcance 1 originado por el consumo de combustible y el alcance 2 originado por el consumo de energía eléctrica, de las cuales el alcance 1 representan al 93% con 3756 toneladas de CO2 frente al 7% de del alcance 2 con 269 toneladas de CO2 equivalente, esto se debe a que para este proyecto por ser de construcción su principal insumo para el desarrollo de sus actividades es el combustible. Ello sirve para que la empresa adopte medidas más orientadas a disminuir sobre lo que más está afectando con las emisiones de GEI y centrar esfuerzos sobre ello.
Este artigo tem como objetivo problematizar a representação da identidade nacional, segundo os integrantes da Liga da Defesa Nacional, entre o final da I Guerra Mundial até a Revolução de 1930, a qual propõe um Projeto de Defesa, mas nele implicando um Projeto de Nação. Esta abordagem tem, como ponto de partida, os discursos proferidos por Olavo Bilac, na fundação da referida entidade, em 1916, identificando, neles, a tentativa da confluência de interesses, norteada pelo poeta, para um Projeto Nacional, baseado, inicialmente, no Serviço Militar Obrigatório, desdobrando-se em uma proposta de Instrução Primária (alfabetização) à população, como estratégias para a construção da identidade nacional. Tal Projeto tinha como objetivo propor a Unidade Nacional, por meio da centralização de Políticas de Estado pelo Governo Federal, objetivando a futura ocupação do espaço geográfico do país, conforme sua concepção própria de nacionalismo e cidadania. Em suma, procuraremos demonstrar, em nossa hipótese, que o objetivo em relação à fundação da Liga de Defesa Nacional, em 1916, era construir um projeto de modernização conservadora do Estado Brasileiro, momento em que os militares, juntamente com os civis, atuaram como Partido Militar, enquanto possibilidade histórica factual.