Study region: The Yellow River Basin (YRB), China. Study focus: This study investigates the spatiotemporal trends of water use efficiency (WUE) in the YRB from 2001 to 2020 using ordinary least squares (OLS) regression and Sen's slope estimator. It integrates multi-source spatial data, random forest, and partial least square-structural equation modeling to identify key drivers and quantify the direct and indirect effects of the main driving forces on WUE, including an analysis of the antagonistic or synergistic relationships between these effects. New hydrological insights for the region: Results showed an overall increase in WUE in the YRB, with OLS and Sen's slopes of 0.02 and 0.128 gC·m−2·mm−1·yr−1, respectively. Key drivers included leaf area index, night lights, soil water, elevation, landform relief, temperature, precipitation, and solar radiation. The five-year average effect intensities ranked as: water conditions (0.646) > leaf area index (0.506) > human actvities (0.235) > radiation–temperature (0.115) > geographic environment (0.070). The direct effect of radiation–temperature on WUE was positive; however, negative indirect effects antagonized this contribution, resulting in a net negative total effect. Water conditions and human activities showed synergistic effects that reinforced their positive impacts, whereas the geographic environment exhibited mainly negative direct effects partially offset by positive indirect consequences. These findings demonstrate that strategically leveraging mediating effects can effectively enhance the sustainability of ecosystem WUE in the basin.
A brief review of diamond mining covers the succession of dominating resources, from India to South Africa, to elsewhere in Africa and then to Russia and Canada. Kimberlite pipes have come to be recognized as the explosive transporters of diamonds upwards from their high‐pressure sources in the deep crust and upper mantle of Archaean cratons.
Tchedele Langollo Yannick, Bilkissou Alim, Mohamadou Alpha Ali
et al.
Abstract This study investigates the potential of micro glass powder as a supplementary cementitious material in Belite cement matrices, addressing both environmental concerns and performance optimization. With the cement industry contributing significantly to global CO2 emissions and glass waste posing recycling challenges, this work explores the synergistic recycling of soda-lime glass in cementitious systems. The primary objectives were to evaluate the influence of glass powder on hydration kinetics, mechanical properties, and microstructure, while developing predictive models for strength behavior. Results demonstrate that glass powder addition (5–35% by weight) enhances workability and extends setting times, with optimal mechanical performance observed at 5–20% substitution. The pozzolanic reactivity of glass powder improved compressive strength by up to 23.6% (56 days) and flexural strength by 18.4% (300 days) compared to plain cement mortars. Microstructural analyses confirmed the formation of secondary calcium silicate hydrates (C-S-H) and reduced porosity in modified pastes. Statistical modeling yielded high-accuracy predictive equations (R2 ≥ 0.92) for strength properties as functions of composition, curing time, and microstructure. These findings highlight the dual benefit of glass powder in mitigating waste and enhancing cement performance, supporting its viability as a sustainable construction material.
Marina Filipović, Tihomir Frangen, Josip Terzić
et al.
ABSTRACTOur study focuses on a sizeable transboundary karst catchment in Croatia and Bosnia and Herzegovina, extending over 2000 km2. A complex underground conduit system and extreme karst forms heterogeneity are the main characteristics of the area in question. Since determining the boundary of such a large and complex catchment is difficult, we used different kinds of data sets, of which the most relevant are the available geological data, hydrochemical data, hydrological data, and tracing tests data, to divide the regional catchment into six subcatchments. We also examined past archived reports and carried out new hydrological investigations of several major and minor springs. Our research results in a hydrogeological map that can be used as a base for establishing site-specific groundwater protection zones, for water balance calculations and the planning of new research in this area, especially the ones regulating combined cross-border efforts to prevent groundwater contamination and ensure sufficient drinking water.
As a new kind of carbonaceous adsorbent, biochar has a good function of controlling VOCs. A series of biochar (BCx) and potassium carbonate activated biochar (KBC-x-y) were pre-pared from corncob for benzene adsorption. Thermogravimetric analysis, nitrogen adsorption-desorption, scanning electron microscopy (SEM) and elemental analysis (EA) were used to char-acterize the pyrolytic properties, specific surface area, pore volume and pore size, surface mor-phology and atomic percentage of the biochar (mass) samples. The effects of carboniza-tion/activation temperature on benzene adsorption were investigated by adsorption experiments. The results show that the specific surface area of biochar modified by potassium carbonate is up to 576.76 m2/g, the pore volume is 0.325 m3/g, and the maximum adsorption capacity of benzene is up to 82.51 mg/g (2.9 times higher than that of unmodified biochar). The carbonization temperature and adsorption capacity show a trend of normal distribution. The adsorption capacity increases with the increase of carbonization temperature, but the high carbonization temperature above 800 ℃ will lead to the clogging of pores, decrease in number, decrease in specific surface area and decrease in adsorption capacity. The adsorption capacity of biochar shows the same trend with the activation temperature under low/high carbonization temperature. After high-temperature carbonization (800 ℃), the optimum activation temperature is 400 ℃ (KBC-800-400). If the activation temperature is too high, it will lead to the fracture of micropore wall and the sintering effect of volatiles, thus reducing the adsorption capacity. Lower activation temperature fails to make K2CO3 fully react on the carbon surface. After low-temperature carbonization (400 ℃), the optimal activation temperature is (800 ℃). The adsorption performance of low-temperature carbonized high-temperature activated biochar (KBC-400-800) is better than that of high-temperature carbonized low-temperature activated biochar (KBC-800-400). It is possibly because the higher activation temperature facilitates the involvement of potassium carbonate in the reaction of the activation process in the case of low temperature car-bonization.