Freeze-thaw cycles coupled with sulfate attack represent one of the most challenging service environments for concrete. This study aims to enhance the durability of concrete materials in environments characterized by sulfate attack and severe freeze-thaw conditions. Specifically, it investigates the deterioration laws and evolution models of mortar materials containing silica fume under both freeze-thaw and coupled freeze-thaw/sulfate attack conditions. Mortar specimens with varying silica fume contents (0%, 6%, 8%, and 10%) were prepared and subjected to single freeze-thaw and coupled freeze-thaw-sulfate attack tests to examine the impact of different silica fume dosages on the durability of mortar materials under these harsh conditions. Additionally, a quantitative assessment model for damage evolution was established using the entropy weight method and Wiener process model. The research findings indicate that silica fume significantly enhances the sulfate resistance and freeze-thaw durability of mortar materials, with an optimal dosage of 10%. Within the scope of this study, higher silica fume content results in a greater number of sulfate attack-freeze-thaw cycles the mortar can endure before damage and failure, thereby extending its service life. Based on the Wiener stochastic process damage model and field data, it is predicted that the service life of mortar containing 10% silica fume increases most notably to 36.6 years, representing a relative improvement of 45.8 % compared to mortar without silica fume. These results provide valuable references and guidance for the design and construction of concrete structures in regions characterized by high-cold temperatures and salt- corrosive soils.

Linqing bricks, a critical material in Chinese Ming-Qing Dynasty royal architecture, face performance deficiencies in modern production compared to historical counterparts, mainly due to uneven temperature fields in kilns and fluctuations in firing quality caused by empirical raw material ratios. Based on a real brick kiln, this study systematically investigates the effects of material composition and firing conditions on brick performance using locally sourced Linqing clay and laterite. Controlled firing experiments were conducted with varying laterite proportions (0-100 wt%), loess proportions (0-100 wt%), clay additions (0-10 wt%), and temperatures (1020-1058 degrees C), followed by comprehensive analyses of physical properties, phase composition, microstructure, and thermal behavior. According to the experimental results, increasing laterite content enhances compressive strength (from 11.9 to 38.1 MPa) and bulk density (from 1.45 to 1.65 g/cm3), with pure laterite achieving optimal performance. A clay content of 5 wt% maximizes mechanical properties, while elevating firing temperature to 1058 degrees C significantly improves strength (increased 13Mpa over 1020 degrees C). Using the CRITIC weighting method, we propose an optimized formulation (50-60 wt% laterite, 40-50 wt% loess, 5 wt% clay) fired at 1058 degrees C. This research not only promotes the standardization and scientific approach of modern Linqing brick production processes but also better controls the overall consistency of the quality of Linqing bricks in kilns. Additionally, it provides a more authentic and reliable material guarantee for the restoration of ancient architectural heritage.

For well-founded decisions in sustainable timber harvesting, it is important to know the preferences of different stakeholders. The concept of sustainable timber harvesting is to incorporate economic, social, and environmental criteria. In a previous study, 33 criteria were identified by forest experts as relevant for evaluating sustainability. To assess the importance of these criteria, an online survey was conducted among Austrian stakeholders between April and May 2023, in which 610 people were invited to participate and which resulted in a response rate of 47%. The survey participants were primarily male (94%), with an average age of 47 and an average of 20 years of work experience. The key criteria for sustainable harvesting that were unanimously mentioned by the stakeholders on the basis of a Likert scale, included occupational hazards, residual stand damage, loss of wood quality due to poor work performance, biomass regeneration, water erosion, noise exposure, soil rutting, physical workload, working conditions, and vibration exposure. Younger or less experienced workers generally rated the criteria as less important than older and more experienced workers. These identified preferences will inform the development of a decision support model for sustainable timber harvesting using these criteria as input parameters.

PurposeWeighting in LCA is important as it supports decision-making by prioritising and determining which impact categories are more important. However, the lack of weighting factors in developing countries forces LCA practitioners to adopt weighting values developed for other countries, leading to a less transparent decision-making process. One transparent and easily reproducible distance-to-target (DtT) weighting method that can be applied in Nigeria is the Swiss-developed ecological scarcity method. This method is based on the ratio of the current environmental situation of a country, region or product to the desired policy targets. The purpose of this study was to apply the ESM to develop weighting factors and eco-factors for Nigeria.MethodsThe normalization and current flows data for emissions and resource use in 2010 (base year) were collected from official data sources, and the critical flows were extracted from corresponding policy targets of the Government of Nigeria in 2030 (target year). The ESM was then applied to the aggregated data to derive Nigeria-specific weighting factors and eco-factors as the quantitative indicators for the emissions and resources.Results and discussionWeighting and eco-factors for emissions and resources were developed for 25 environmental issues in Nigeria. NOx, total petroleum hydrocarbon and land use weigh heavily. Except for carcinogenic substances in the air, emissions to water resulted in high eco-factors: TPH, phenol, total nitrogen, nitrate, ammonia and heavy metals (human and ecotoxicity). Policymakers in Nigeria need to set quantitative emission reduction targets for substances and such as carcinogenic substances in the air, oil spills and metal mineral resources.ConclusionsThe ESM was used to develop Nigeria's eco-factors as quantitative indicators for emissions or resource use using the normalization and current flows in 2010 obtained from government data sources as base year data. The critical flows were extracted from the policy targets of the government of Nigeria, with 2030 as the target year. The eco-factors can support environmental sustainability decision-making in Nigeria. Future methodological development should apply updated policy targets and more data to calculate eco-factors for missing substances such as waste (radioactive and non-radioactive), heavy metal emissions to air and soil, emissions to groundwater, photochemical ozone creation substances and phosphorous in surface water and soil.

Relevance. The surfaced of a gas pipeline, ballasted with weights, in a swamp qualifies as > and must be decommissioned. Aim. To establish the effect of the weight of weighting agents on a gas pipeline ascent in a swamp. The weight depends on the concentration of moles soluble in water, changes in the values of the physico-mechanical characteristics of the soil due to its watering, and the parameters of the gas pipeline operation. Objects. Sections of a gas pipeline, ballasted with weights, in a swamp in a watered area. Methods. Modeling the stress-strain state of a gas pipeline, ballasted with weighting agents, in a swamp by a one-dimensional rod system consisting of rods and their coupling nodes; integration by the Godunov orthogonal run method of a normal system of nonlinear ordinary differential equations describing the stress-strain state of the rods and compiling a solution of systems of algebraic equilibrium equations in the coupling nodes, taking into account the impact of weighting agents on stress-strain state. Results. The paper introduces the brief information on the surfacing of gas pipelines with weights installed on them. The authors have set and solved the problem of the stress-strain state of the of the gas pipeline consisting of the middle underwater part, ballasted with reinforced concrete weights, and the extreme flooded underground parts. The analysis of the stress-strain state of the gas pipeline established the following main reasons for its ascent: uneven unequal sedimentation of the base soil on the extreme parts, in which the pipe remains in a trench filled with soil; reducing the weight of weighting agents in water due to an increase in the specific gravity of water due to the growth of concentration of moles dissolved in water. The authors found the critical values of the operating parameters, at which the bulging of the pipe with an upward deflection arrow begins, preceding the ascent of the gas pipeline.

Due to the complex and multi-dimensional nature of droughts, it is not possible to assess droughtinduced damage and its consequences for various social, economic, and environmental aspects of societies by relying only on a univariate index such as precipitation-based drought indices. The present study aimed to develop a practical and scientific framework based on hazard, vulnerability (social, economic, and environmental), and coping capacity to generate a drought risk map for the hot and dry climate regions of Iran. Accordingly, the Drought Hazard Index (DHI), Drought Vulnerability Index (DVI), and Drought Coping Capacity Index (DCCI) were derived from the Standardized Precipitation Evapotranspiration Index (SPEI), 16 social, economic and environmental variables and three social, economic variables, respectively. The layers of all variables of the three indices in the GIS were provided, and they were combined in the form of an equation to produce a drought hazard map of central and southeastern Iran. The results indicate that the counties most and least vulnerable to drought were located in the southeast and west of the case study area, respectively. A number of large households, long distances from provincial centers, and soil erosion were the most important social, economic, and environmental factors making the southeast of the case study (including south of Sistan and Baluchestan and south of Kerman provinces) most vulnerable to drought. Due to their high drought coping capacity, counties located in the west of the case study (west of Kerman and south of Yazd provinces) were least vulnerable to drought. Extended support for low-income households by charitable organizations, tertiary education, and most importantly, a variety of jobs and career opportunities were the most important factors in reducing vulnerability in this part of Iran. Furthermore, our methodology by taking social, economic, and environmental dimensions into account as risk, vulnerability, and coping capacity indices can be far more efficient than the methods considering only risk and vulnerability factors.

Identifying soil erosion-prone zones in an ungauged river basin is crucial for devising and implementing timely soil protection measures to mitigate soil degradation and protect soil quality. Soil erosion damages the fragile ecosystem, decreases soil fertility, and reduces reservoir water storage, thereby impacting food production. The prime motive of the current research work is to assess and categorize on the basis of priority the sub-watersheds (SWs) susceptible to substantial soil erosion in the Ponnaniyar River basin (an ungauged river basin) based on the morphometric parameters that impact soil erosion. To achieve this research objective, four multi-criteria decision-making (MCDM) approaches based on the outranking approach and synthesis method are adopted to facilitate the decision-making process by considering an integrated and balanced assessment of multiple complex parameters for devising effective soil conservation measures to minimize soil erosion. Cartosat-1 digital elevation model (DEM) is employed to extract eighteen morphometric parameters under linear, shape, areal, relief and hypsometric aspects. The priority of SWs obtained by different MCDM techniques is evaluated using percentage of variation and intensity of variation. The outcomes show that the MABAC method is effective in prioritizing SWs with the least percentage of variation (59.61%) and intensity of variation (4.397). It is also found to be the best method for integration with the RSS method for determining SW priority with a root sum of squares value of 43. SW1 is identified to be highly vulnerable to soil erosion with a grade average value of 1.00 followed by SW2 (3.00), SW3 (3.25) and SW13 (5.00), requiring immediate implementation of watershed planning and management measures to control the extent of soil erosion and safeguard soil resources.

The identification of areas prone to soil erosion in ungauged river basins is crucial for timely preventive measures, as erosion causes significant damage by lowering soil productivity and filling reservoirs with sedimentation. This study proposes a novel approach to prioritize sub-watersheds (SWs) in Ponnaniyar river basin. It utilizes different combinations of five objective-based weighting methods and seven Multi-criteria Decision Making (MCDM) techniques under outranking and synthesis methods with soil loss, morphometry, land use/land cover (LULC), and topography parameters. The results obtained from different hybrid models are validated using metrics like percentage and intensity of change. The findings reveal that MW-PROMETHEE (53.85%) and CRITIC-WASPAS (8.31) perform best in prioritizing areas based on morphometry, while CRITIC-TOPSIS (48.35% and 7.58) is more effective in prioritizing areas based on land use/land cover (LULC) and topography. The grade average method is used to integrate the rankings from 71 models: 35 based on morphometry, 35 based on LULC, and 1 based on the RUSLE model. The analysis identifies SW2 with a grade value of 4.34 as severely affected by soil erosion, followed by SW11 (5.45), SW5 (5.56), and SW9 (5.68), all falling within the very high priority level. This study recommends implementing appropriate water harvesting structures, which might be helpful in mitigating soil degradation, promoting soil conservation, and ensuring sustainable agricultural productivity.