Geopolymer-based cementitious materials known for their robust durability and lower environmental impact make them an ideal choice for sustainable construction. The main focus of this study is to understand the influence of chemical admixtures which plays a pivotal role in improving the properties of geopolymer mortar (GM). This research integrates various chemical admixtures, including calcium chloride, sodium sulphate, sodium hexametaphosphate, and MasterGlenium SKY 8233 (SKY) which falls under the category of either accelerators, retarders, or superplasticisers. Assessments were conducted on the fresh and hardened states of flyashbased GM mixes with varying proportion of river sand (RS), laterite soil (LS) and copper slag (CS), encompassing flowability, setting times, compressive strength, durability study in aggressive environmental conditions and microstructural analyses after 56 days of ambient curing. Findings reveal that calcium chloride and sodium sulphate efficiently decrease the initial and final setting times of the geopolymer paste, highlighting their roles as accelerators, with calcium chloride showing greater efficacy than sodium sulphate. On the other hand, sodium hexametaphosphate serves as a retarder, substantially extending the initial setting time of the geopolymer paste. Introducing the modified polycarboxylic ether (PCE) based superplasticiser SKY into the mortar matrix caused the initial setting time to be extended and resulted in a slight drop in compressive strength compared to the other mixes. Durability tests confirmed the superior resistance of GM mixes to harsh environments like acid, sulphate, and marine water exposure. These findings highlight the potential for tailoring geopolymer blends to achieve desired properties under ambient curing conditions using chemical admixtures.

Saline soils are significantly affected by water-salt phase changes, evaporation, and groundwater during seasonal freezing and thawing. For the study of physical and mechanical properties of saline soils, solubility is an important indicator that varies with temperature. However, there have been very limited computational studies on solubility at low temperatures. The model for calculating the solubility of Na2SO4-NaCl-H2O ternary system under low temperature conditions was constructed in this paper, based on the Pitzer and BET models. Improvements were made to the parameters & empty; and gamma in the Pitzer model, while improvements were made to the parameters c, r, and aw in the BET model. The solubility changes within the range of 273.15 K-373.15 K were calculated and validated by combining them with indoor experiments. It was found that both the improved Pitzer model and BET model accurately predicted relative equilibrium solubility data of the Na2SO4-NaCl-H2O ternary system at temperatures ranging from 273.15 K to 373.15 K. Additionally, compared with the Pitzer model, the BET model had advantages such as easy parameter acquisition and wider application range. The findings from this research hold great significance for understanding the process and patterns of salt analysis during soil freeze-thaw cycles as well as providing a scientific foundation for further comprehension of phase change laws and physical properties related to saline soils.

The effect of polyphenylene sulfide binder content on the properties of injection molding polyphenylene sulfide/NdFeB magnets were investigated. The maximum filling amount of NdFeB magnetic powder was 87.6 wt.-%, and the mixing process and subsequent injection molding of the polyphenylene sulfide/NdFeB were in good condition. The melt mass-flow rate of the polyphenylene sulfide/NdFeB granular materials reached 121.7 g/10 min, the compressive strength of the polyphenylene sulfide/NdFeB magnet was 92.18 MPa, and its maximum magnetic energy product reached 5.59 MGOe. The structure and morphology characteristics of polyphenylene sulfide/NdFeB magnets were investigated using scanning electron microscopy and atomic force microscopy. The corrosion behavior of polyphenylene sulfide/NdFeB magnets was also studied using potentiodynamic polarization curves and electrochemical impedance spectroscopy. The results indicated that the injection molding process facilitated the uniform coating of polyphenylene sulfide particles on NdFeB powder, which directly enhanced the corrosion resistance of polyphenylene sulfide/NdFeB magnets. With an increase in polyphenylene sulfide content, the surface of polyphenylene sulfide/NdFeB magnets became more uniform. The corrosion current density of 13 wt.-% polyphenylene sulfide/NdFeB magnet was approximately one order of magnitude lower than that of 9 wt.-% polyphenylene sulfide/NdFeB magnet, indicating an improved corrosion resistance of polyphenylene sulfide/NdFeB magnet.

Among climate-change related effects, drought, heat, and waterlogging are the most important adversely affecting the production of potatoes in Europe. As climate change progresses, agricultural practices must adapt to maintain potato yields. This study is based on a European-wide survey. It presents potato growers' perception of climate change, its impact, and possible adaptation strategies, focusing on the results from Germany, Switzerland, and Austria. Potato growers strongly agreed that climate change had affected their potato production in the last ten years, as indicated by 98% of German and more than 90% of Swiss and Austrian respondents. Drought caused the most severe impact, and to varying extents damage was caused by heat and the occurrence of pests and pathogens. The most preferred adaptation measure was the planting of adapted varieties. In line with the comparably low access to at least partial irrigation that Austrian potato growers reported, Austria appeared to be the country most affected by drought. Other more pronounced challenges were late spring frost, flash floods, and soil erosion. The study highlights and discusses specific differences between the countries, as well as between conventional and organic potato production based on the Austrian responses. The results underline that to successfully develop effective climate change mitigation strategies, country-specific and local challenges and needs should be considered.

Knowledge about changes in ground temperatures under a changing climate is important for many environmental, economic, and infrastructure applications and can be estimated by transient numerical simulations. However, a full annual cycle of precipitation data is needed to achieve this, yet is often unavailable in high alpine regions where a lack of infrastructure precludes installation of heated instruments capable of measuring the solid precipitation component. This paper presents a method to reconstruct a full year precipitation dataset at high alpine weather stations, which is then used to model ground temperature and snow depth for 16 alpine sites in Switzerland for the past and three climate scenarios. Differences in the possible temperature trajectories are highlighted with a focus on elevation and regional climatic differences within Switzerland. Snow height and ground temperatures under a changing climate are modeled with the one-dimensional physical model SNOWPACK by applying a delta change signal to the meteorological data set obtained from the CH2011 climate scenarios of Switzerland. All sites showed a decrease of snow cover, a shortening of the snow season and an increase in ground temperature to the end of the century. Sites in the inner alpine regions of Grisons were found to be less sensitive to climate change than sites in the western Alps. The magnitude of reduction of mean snow height depends mainly on location, whereas for the contraction of the snow season elevation is the key factor. It could be shown that the temperature-precipitation combination as expressed in the snow dynamics explain changes in ground temperatures more than the individual changes in either parameter. Alpine meadow and thin snow cover appear to delay warming of the ground.