Expanded Polystyrene (EPS) granular lightweight soil (ELS) is an eco-friendly material made of EPS particles, cement, soil, and water. This study investigates the modification of ELS using a silane coupling agent (SCA) solution to improve its performance. Various tests were performed, including flowability, dry shrinkage, unconfined compressive strength (UCS), triaxial, hollow torsional shear, and scanning electron microscopy (SEM) analysis, to evaluate the physical and mechanical properties at different SCA concentrations. The results show that the optimal SCA concentration was 6%, improving flowability by 13% and increasing dry shrinkage weight by 4%. The UCS increased with SCA concentration, reaching 266 and 361 kPa after 7 and 28 days, respectively, at 6% SCA. Triaxial and shear tests indicated improved shear strength, with the maximum shear strength reaching 500 kPa, internal friction angle rising by 4%, and cohesion reaching 114 kPa at 6% SCA. Hollow torsion shear tests showed that 6% SCA enhanced stiffness and resistance to deformation, while reducing the non-coaxial effect. SEM analysis revealed that SCA strengthened the bond between EPS particles and the cement matrix, improving the interfacial bond. This study highlights the potential of modified ELS for sustainable construction.
青藏高原冰川正处于加速消融状态,如何从冰川变化的物理过程理解其变化机理并预测未来变化,是应对冰川变化及其影响的重要途径,但现有模型都是利用经验模型简化了冰川表面的水热过程,忽略了地形、反照率和辐射等要素导致冰川变化的空间差异性,造成对模拟结果的不确定性.本文充分考虑了地形对太阳辐射的影响,并由深度学习法获得冰川表面的反照率,以解决前期无法精确计算冰川表面获得的太阳辐射以及冰雪反照率这一难点,建立了适用于无观测地区的冰川分布式能量物质平衡模型,并同冰川动力过程相耦合,建立了基于冰川物理变化过程的三维模型.以祁连山老虎沟12号冰川为例,证明该模型对山地冰川变化的模拟有较强的适用性.进一步预估在SSP2-4.5情景下,老虎沟冰川到21世纪末将损失60%的冰量,而在SSP5-8.5情景下将几乎完全消失.本项研究为强化冰川模拟和预测提供了新途径.
青藏高原冰川正处于加速消融状态,如何从冰川变化的物理过程理解其变化机理并预测未来变化,是应对冰川变化及其影响的重要途径,但现有模型都是利用经验模型简化了冰川表面的水热过程,忽略了地形、反照率和辐射等要素导致冰川变化的空间差异性,造成对模拟结果的不确定性.本文充分考虑了地形对太阳辐射的影响,并由深度学习法获得冰川表面的反照率,以解决前期无法精确计算冰川表面获得的太阳辐射以及冰雪反照率这一难点,建立了适用于无观测地区的冰川分布式能量物质平衡模型,并同冰川动力过程相耦合,建立了基于冰川物理变化过程的三维模型.以祁连山老虎沟12号冰川为例,证明该模型对山地冰川变化的模拟有较强的适用性.进一步预估在SSP2-4.5情景下,老虎沟冰川到21世纪末将损失60%的冰量,而在SSP5-8.5情景下将几乎完全消失.本项研究为强化冰川模拟和预测提供了新途径.
青藏高原冰川正处于加速消融状态,如何从冰川变化的物理过程理解其变化机理并预测未来变化,是应对冰川变化及其影响的重要途径,但现有模型都是利用经验模型简化了冰川表面的水热过程,忽略了地形、反照率和辐射等要素导致冰川变化的空间差异性,造成对模拟结果的不确定性.本文充分考虑了地形对太阳辐射的影响,并由深度学习法获得冰川表面的反照率,以解决前期无法精确计算冰川表面获得的太阳辐射以及冰雪反照率这一难点,建立了适用于无观测地区的冰川分布式能量物质平衡模型,并同冰川动力过程相耦合,建立了基于冰川物理变化过程的三维模型.以祁连山老虎沟12号冰川为例,证明该模型对山地冰川变化的模拟有较强的适用性.进一步预估在SSP2-4.5情景下,老虎沟冰川到21世纪末将损失60%的冰量,而在SSP5-8.5情景下将几乎完全消失.本项研究为强化冰川模拟和预测提供了新途径.
青藏高原冰川正处于加速消融状态,如何从冰川变化的物理过程理解其变化机理并预测未来变化,是应对冰川变化及其影响的重要途径,但现有模型都是利用经验模型简化了冰川表面的水热过程,忽略了地形、反照率和辐射等要素导致冰川变化的空间差异性,造成对模拟结果的不确定性.本文充分考虑了地形对太阳辐射的影响,并由深度学习法获得冰川表面的反照率,以解决前期无法精确计算冰川表面获得的太阳辐射以及冰雪反照率这一难点,建立了适用于无观测地区的冰川分布式能量物质平衡模型,并同冰川动力过程相耦合,建立了基于冰川物理变化过程的三维模型.以祁连山老虎沟12号冰川为例,证明该模型对山地冰川变化的模拟有较强的适用性.进一步预估在SSP2-4.5情景下,老虎沟冰川到21世纪末将损失60%的冰量,而在SSP5-8.5情景下将几乎完全消失.本项研究为强化冰川模拟和预测提供了新途径.
Shredded rubber from waste tyres has progressively been adopted in civil engineering due to its mechanical properties, transforming it from a troublesome waste into a valuable and low-cost resource within an eco-sustainable and circular economy. Granular soils mixed with shredded rubber can be used for lightweight backfills, liquefaction mitigation, and geotechnical dynamic isolation. Most studies have focused on sand-rubber mixtures. In contrast, few studies have been conducted on gravel-rubber mixtures (GRMs), primarily involving poorly-graded gravel. Poorly-graded gravel necessitates selecting grains of specific sizes; therefore, from a practical standpoint, it is of significant interest to examine the behaviour of well-graded gravel and shredded rubber mixtures (wgGRMs). This paper deals with wgGRMs. The results of drained triaxial compression tests on wgGRMs are analysed and compared with those on GRMs. Stress-strain paths toward the critical state and energy absorption properties are evaluated. The tested wgGRMs exhibit good shear strength and remarkable energy absorption properties; thus, they can be effectively utilised in several geotechnical applications.
The excessive use of cobalt in various chemical industries and arbitrary discharge of industrial wastewater have led to increased cobalt pollution in soil and water resources, increasing the risk of human exposure to high concentrations of cobalt and necessitating an urgent need for on-site monitoring platform for cobalt pollution. In this study, the terminal deoxynucleotidyl transferase (TdT)-CRISPR platform has been developed. In this platform, cobalt as a cofactor of TdT, can significantly improve the tailing efficiency of TdT-mediated extension. Therefore, when cobalt is present, the detection probe can be extended with poly(T) tails through the TdTmediated extension, which can be subsequently served as the DNA activator for Cas12a, leading to the cleavage of fluorescence reporter molecules and triggering turn-on fluorescence signals. Consequently, this dual amplification sensing strategy of TdT-CRISPR platform demonstrated exceptional sensitivity (0.83 nM) and high specificity for cobalt over other ions. Furthermore, the method was successfully employed for the detection of cobalt in tap water and river samples. CRISPR-lateral flow assays (CRISPR-LFAs) were evaluated in this study for the simple and point-of-care detection of cobalt pollution. The assays are capable of detecting cobalt concentrations as low as 50 nM, which is significantly lower than the environmental standards of 16.9 mu M, through strip analysis with the naked eye. These results commonly suggest that the TdT-CRISPR platform holds significant promise for monitoring cobalt pollution, providing a robust and sensitive solution for on-site detection and contributing to the mitigation of cobalt contamination risks in environmental matrices.
The present work attempts to investigate the applicability of using recycled aggregate for the development of pervious concrete and for mitigating liquefaction and reliquefaction effects. The dynamic behaviour of developed recycled aggregate-based pervious concrete pile is compared with natural aggregate-based pervious concrete pile. The study attempts to explore the inherent material properties of pervious concrete keeping permeability equivalent to conventional stone columns but with improved mechanical characteristics with enhanced pore water pressure ratio reduction and soil displacement reduction efficiency under repeated incremental acceleration loading conditions. For testing, 1g shaking table tests were performed with 01 g, 02 g, 03 g and 04 g acceleration loading with 5 Hz frequency. The outcomes obtained from this experimental study infer that recycled aggregate-based pervious concrete pile exhibits a superior performance compared with natural aggregate-based pervious concrete pile. Overall, the use of recycled aggregate found sustainable approach for developing pervious concrete pile and found effective ground improvement application against liquefaction and reliquefaction hazards.
Mercury (Hg) is a notorious toxic heavy metal, causing neurotoxicity and liver damage, posing grave threats to human health and environmental safety. There is an urgent imperative for developing novel Hg2+ detection methods. In this work, we developed a CRISPR-based method for Hg2+ detection named CRISPR-Hg. A CRISPR/ Cas12a system was employed and could be activated by the PCR product, generating fluorescence signals based on the trans-cleavage activity. CRISPR-Hg exhibited remarkable selectivity and specificity, achieving a detection limit of 10 pM and minimal interference with background signals. This approach has been successfully applied to detect Hg2+ in real samples, including water, soil, and mushroom. Ulteriorly, a portable device was devised to streamline the readout of fluorescence signals by a smartphone within 30 min. We offer an affordable, highly selective and visually interpretable method for Hg2+ detection, with the potential for broad application in Hg2+ monitoring for food safety and public health.
The SLS additive manufacturing industry enables the development of products for diverse applications with distinct properties due to its excellent surface finish and ability to create varied part geometries, but it consumes high-performance materials with high acquisition costs. An extensive quarrying of stone leads to the accumulation of mineral residues, posing environmental hazards by contaminating soil and water when disposed of in landfills. The primary objective of the study was to incorporate mineral waste into the SLS technique and investigate the influence of its addition, along with a silane-based chemical treatment, on the mechanical performance of polymer-mineral composites (PA12-slate). Additionally, the feasibility of producing a highly loaded printed prototype, employing 50 wt% of mineral waste, was examined. Samples of PA12, PA12 blended with 50 wt% slate waste, and slate waste treated with silane underwent fabrication via selective laser sintering (SLS) and subsequent mechanical characterization, including tensile, flexural, and compressive tests. Additionally, the samples underwent accelerated aging using a QUV weathering tester, followed by mechanical characterization. The geometric accuracy, stability, and processing feasibility of these formulations were evaluated through SLS-printed composite prototypes utilizing PA12_50Sla_Si. It was found that the addition of 50% of slate to the PA12 presented mechanical properties decreasing compared to the printed PA12 only. However, an increase was verified when using silane-induced mineral bonding. The incorporation of mineral agents and silane enhanced the resistance of PA12 to aging. However, after aging, both tensile and flexural strength decreased across all printed samples. Nonetheless, this study showcased the feasibility of producing complex PA12-slate waste specimens containing up to 50 wt% of mineral waste using the SLS printing technique. Therefore, SLS presents itself as a viable means of adding value to this mineral waste.