The paper investigates the effect of curing conditions on the properties of laterite soil-based geopolymer cement. In the experimental testing, calcined laterite soil was used as a solid precursor in the preparation of geopolymer cement. Standard size prismatic geopolymer specimens were prepared and subjected to four curing methods, including open air curing and courses of combined open-air curing and oven curing. The prisms were tested at 3, 7, and 28 days to determine the effect of curing methods on the flexural and compressive strengths. The crushed prisms were further pulverised and analysed to investigate the microstructure, elemental composition, mineralogical phases, chemical bonding, and thermal behaviour. The findings showed that the highest strength at 28 days was obtained with the air curing method. However, the curing methods involving an oven curing course resulted in the highest early strength at 3(early strength) and 7 days.
This study evaluated the usability and effectiveness of robotic platforms working together with foresters in the wild on forest inventory tasks using LiDAR scanning. Emphasis was on the Universal Access principle, ensuring that robotic solutions are not only effective but also environmentally responsible and accessible for diverse users. Three robotic platforms were tested: Boston Dynamics Spot, AgileX Scout, and Bunker Mini. Spot's quadrupedal locomotion struggled in dense undergrowth, leading to frequent mobility failures and a System Usability Scale (SUS) score of 78 +/- 10. Its short, battery life and complex recovery processes further limited its suitability for forest operations without substantial modifications. In contrast, the wheeled AgileX Scout and tracked Bunker Mini demonstrated superior usability, each achieving a high SUS score of 88 +/- 5. However, environmental impact varied: Scout's wheeled design caused minimal disturbance, whereas Bunker Mini's tracks occasionally damaged young vegetation, highlighting the importance of gentle interaction with natural ecosystems in robotic forestry. All platforms enhanced worker safety, reduced physical effort, and improved LiDAR workflows by eliminating the need for human presence during scans. Additionally, the study engaged forest engineering students, equipping them with hands-on experience in emerging robotic technologies and fostering discussions on their responsible integration into forestry practices. This study lays a crucial foundation for the integration of Artificial Intelligence (AI) into forest robotics, enabling future advancements in autonomous perception, decision-making, and adaptive navigation. By systematically evaluating robotic platforms in real-world forest environments, this research provides valuable empirical data that will inform AI-driven enhancements, such as machine learning-based terrain adaptation, intelligent path planning, and autonomous fault recovery. Furthermore, the study holds high value for the international research community, serving as a benchmark for future developments in forestry robotics and AI applications. Moving forward, future research will build on these findings to explore adaptive remote operation, AI-powered terrain-aware navigation, and sustainable deployment strategies, ensuring that robotic solutions enhance both operational efficiency and ecological responsibility in forest management worldwide.
The production of industrial hemp (Cannabis sativa L.) has expanded recently in the US. Limited agronomic knowledge and supply chain issues, however, stemming from a long-standing cultivation ban, pose a barrier to continued market expansion of hemp, which leads to the import of most hemp products. This review examines the most recent cultivation methods, fertilizer and nutrient requirements, soil management practices, environmental parameters, and post-harvest processing methods, particularly in the context of environmental benefits such as soil phytoremediation and CO2 sequestration. Details of the valorization of hemp biomass into sustainable products, such as fibers, papers, packaging, textiles, biocomposites, biofuels, biochar, and bioplastics, along with current limitations and scope for improvements, are explored. Finally, an overall summary of the life cycle and techno-economic analysis aimed at optimizing their environmental performance and economic feasibility are discussed with a focus on inter with the growing circular economy paradigm.
The objective of the current study is to explore the effect of biostimulation treatment methods on the mechanical properties and microstructure characteristics of biocemented soil. Biostimulated microbially induced carbonate precipitation (MICP) is an eco-friendly and economical soil reinforcement measure. It relies on the stimulation of the urease-producing bacteria (UPB) in situ for the MICP process. Different biostimulation treatment methods involve different oxygen availability, stimulation solution content and distribution, and number of biostimulation treatments. There may be differences in the effect of UPB stimulation and biocementation when different biostimulation treatment methods are used. In this study, four biostimulation treatment methods, i.e., unsaturated single biostimulation treatment (USBT), unsaturated multiple biostimulation treatments (UMBT), saturated single biostimulation treatment (SSBT) and saturated-unsaturated-combined single biostimulation treatment (CSBT), were used to stimulate native UPB in soil columns, and then, the same cementation treatment was applied to the soil columns. Subsequently, the mechanical behavior and microstructural properties of the biocemented soil were investigated. The results indicated that the saturated single biostimulation treatment was more conducive to stimulating native UPB to induce CaCO3 precipitation. Samples subjected to the saturated single biostimulation treatment exhibited higher CaCO3 precipitation content (CCP), dry density, unconfined compressive strength (UCS) and lower permeability within the same cementation treatment cycle (NC). However, UCS was not only determined by CCP, but was also regulated by CaCO3 spatial distribution and precipitation pattern. This study could help guide the selection of biostimulation treatment methods.
Chemical discharge into water has contaminated various locations globally, endangering humans and aquatic life. Industries, farms, wastewater treatment plants, and stormwater overflows release chemicals. The European Union has set pollutant concentration criteria in drinking, surface, and groundwater to reduce water pollution. To comply with these limits, analytical detection methods must be rapid, reliable, and able to identify even minute levels of chemicals. Agriculture uses pesticides to keep crops safe from illnesses, insects, and weeds. Few chemicals work, while the remainder sink into the soil and damage ground and surface water. Due to the growing emphasis on scene analytes over chromatographic approaches, new pesticide evaluation methods have been prioritized. This report summarises various electrochemical pesticide detection studies in a simple and targeted manner. This study examines the electrochemical detection of carbamates, organophosphorus, organochlorine, pyrethroids, and pyrethrins. Electrochemical diagnostic methods, electrode materials, electrolyte and pH of interesting samples, and sample matrices are examined. This paper will also discuss current advances in the respected study, analytical obstacles, and future opportunities. Many electrochemical investigations and analytical data are summarised in this article, which also describes the linear dynamic range of concentration and limit of detection for electrochemical pesticide sensing. This review discusses electrochemical pesticide sensing advances in the utilization of various nanomaterials.
For offshore platforms installed in seismically active regions, maintaining the safety of operations is an important concern. Therefore, the reliability of these structures, under earthquake ground motions, should be evaluated accurately. In this study, reliability methods are applied to determine the probability of failure of jacket platforms against extreme level earthquake (ELE), considering uncertainties in ground motions and the properties of the structure and soil. They are verified by two variance reduction Monte Carlo sampling methods to find the most efficient method in terms of both accuracy and calculation time. During the ELE event, also called strength level earthquake, structural members and foundation components are permitted to sustain localised and limited nonlinear behaviour, so a force-based criterion is utilized for the limit-state function. The results indicate that all reliability methods, except for FOSM, provide a good approximation of the probability of failure. Also, Point-fitting SORM is the most efficient method.
Observations by the Lunar Prospector and the Lunar Atmosphere and Dust Environment Explorer spacecraft suggest the existence of a near-global deposit of weakly bound water ice on the Moon, extending from a depth of a decimetre to at least three metres. The existence of such a layer is puzzling, because water ice would normally desorb at the prevailing temperatures. We here determine the conditions for long-term thermal stability of such a reservoir against solar and meteoroid-impact heating. This is done by using the highly versatile thermophysics code nimbus to model the subsurface desorption, diffusion, recondensation, and outgassing of water vapour in the porous and thermally conductive lunar interior. We find that long-term stability against solar heating requires an activation energy of similar to 1.2 eV in the top metres of lunar regolith, and a global monthly night time exospheric freeze out amounting to similar to 1 tonne. Furthermore, we find that a lower similar to 0.7 eV activation energy at depth would allow for water diffusion from large (0.1-1 km) depths to the surface, driven by the radiogenically imposed selenotherm. In combination with solar wind-produced water, such long-range diffusion could fully compensate for meteoroid-driven water losses. These results are significant because they offer quantitative solutions to several currently discussed problems in understanding the lunar water cycle, that could be further tested observationally.
To investigate the asymmetric deformation and stress characteristics of tunnels and support structures in high geostress layered fractured rock, this paper establishes two refined modeling methods: a numerical model for anchor bolt failure and a model for fractured layered surrounding rock, while considering the spatial variability of soil. The study analyzes tunnel deformation and bolt tensile-shear fracture mechanics under varying bedding angles. The results indicate that: (1) the most unfavorable stress position for tunnel structures in layered fractured rock typically occurs normal to the bedding planes; (2) the tunnel's asymmetric deformation is due to normal compressive and tangential sliding effects of geostress on the bedding planes. When the bedding angle is gently inclined, significant extrusion deformation occurs at the tunnel crown and invert; when steep, substantial tangential sliding forces cause maximum deformation at points where the bedding direction is tangent to the tunnel profile. (3) Fracture development in the surrounding rock primarily occurs normal to the foliation planes, similar to maximum displacement deformation patterns, while other areas propagate outward due to joint shear slip. (4) In layered fractured rock, failed bolts predominantly show tensile-shear fractures, influenced by bedding angle, particularly near the left shoulder to the crown and right invert. Finally, based on the deformation characteristics of layered fractured surrounding rock and the mechanical properties of anchor rod fracture, reasonable differential support optimization measures were proposed, and the simulation results were applied to the Yangjiaping Tunnel of the Chenglan Railway in China.
Soil improvement is one of the most important issues in geotechnical engineering practice. The wide application of traditional improvement techniques (cement/chemical materials) are limited due to damage ecological environment and intensify carbon emissions. However, the use of microbially induced calcium carbonate precipitation (MICP) to obtain bio-cement is a novel technique with the potential to induce soil stability, providing a low-carbon, environment-friendly, and sustainable integrated solution for some geotechnical engineering problems in the environment. This paper presents a comprehensive review of the latest progress in soil improvement based on the MICP strategy. It systematically summarizes and overviews the mineralization mechanism, influencing factors, improved methods, engineering characteristics, and current field application status of the MICP. Additionally, it also explores the limitations and correspondingly proposes prospective applications via the MICP approach for soil improvement. This review indicates that the utilization of different environmental calcium-based wastes in MICP and combination of materials and MICP are conducive to meeting engineering and market demand. Furthermore, we recommend and encourage global collaborative study and practice with a view to commercializing MICP technique in the future. The current review purports to provide insights for engineers and interdisciplinary researchers, and guidance for future engineering applications.
Gully erosion on agricultural land severely damages land resources and affects agricultural production. Topographic features, tillage methods, and roads are major elements constituting the farmland landscape, but the effect of their distribution in the farmland on the gully erosion is still unclear. This study examined the long-term impacts of changes in the farmland environment and climate change on gully erosion over a long temporal scale of nearly 60 years, the results showed that farmland reclamation over the past 60 years had led to a 2324.2 % increase in gully length density and a 3563.3 % increase in gully area density. The increase in annual rainfall amount and the frequency of extreme rainstorms had led to a rapid increase of gully erosion intensity in the last decade, with an average development rate in length density and area density of 61.5 m km- 2 and 778.7 m2 km- 2, respectively. Farmlands with slope aspects between 135 and 270 degrees were more prone to gully erosion, which was related to the redistribution of snow on hillslopes caused by prevailing wind directions. Tillage methods and roads simultaneously affect gully erosion, with newly formed gullies located in farmlands and roadsides accounting for 63.0 % and 29.8 %. Gullies in regions where the angle between furrows and unpaved roads exceeded 70 degrees accounted for 61.1 % of the total roadside gullies. Over the last decade, the annual average increase of gully length and area was 9.8 m yr-1 and 246.1 m2 yr-1. The development rate of gully area was significantly correlated with the drainage area.