The seismic response of monopile foundations is a growing area of research as the offshore wind industry expands worldwide, including in earthquake prone regions of the world. This paper presents dynamic centrifuge tests aimed at investigating the dynamic response of monopiles in both dry and saturated sandy soils. The latter case includes soil liquefaction under strong input motions, with measured excess pore pressures indicating liquefaction. The natural frequency of the monopile-soil system is experimentally determined by measuring the response to a sine sweep motion. Strong earthquakes are then applied at this frequency and its harmonics. This paper discusses the response of the monopile in terms of the peak accelerations observed in the dry and saturated tests, as well as using response spectra and amplification ratios. The dynamic bending moments along the pile are also measured to infer the bending moment profile with depth. Finally, two identical monopiles are pushed-over in each of the centrifuge tests to establish the pre and post-earthquake monotonic response, including the lateral stiffness and capacity, which are compared for the dry model tests and the saturated case.

Due to climate change and human activity, biotic constrainers are anticipated to expand to regions where they were previously irrelevant. This will present new management challenges for crops, particularly in cropping systems dependent on minor cereals diversification. In Central and Eastern Europe, Secale cereale is a minor cereal that contributes to the diversity of crop species, particularly in marginal areas where wheat cultivation is unfavourable. During 2020-2021, using different chemical and biological pesticide formulations, a plant-pest-pathogen interaction profile was observed on Suceveana rye genotype in a randomized complete block design with three replications in dry area from South of Romania. The best protection against leaf rust (Puccinia recondita f. sp. secalis) was provided by Poliversum (Pythium oligandrum M1, 1x10.000.000 oospors/g product) for the 1st assessment -attack degree = 0.65% and for the 2nd assessment -attack degree = 1.42%, while against pests was provided by Bioinsekt and deltametrin (0.75 ml/ha). Negative and significant correlation of leaf rust attack with grain yield (r =-0.8561***) and pests attack with grain yield (r =-0.8631***) were found during 2020-2021 cropping season.

Sandy bank slopes are widely distributed near rivers and lakes, and desiccation cracking is ubiquitous on the slopes' surface. It negatively impacts the mechanical and hydraulic properties of the topsoil. Sand grains have a profound effect on the structure and physical properties of the sand-soil mixture. This study investigated the effect of incorporating sand on the desiccation cracking and moisture dynamics of mixed soil at temperatures of 35, 50, and 65 degrees Celsius and to reveal the mechanism of sand grains influencing the desiccation cracking. The sand contents selected are 0%, 10%, 20%, 30%, 40%, 50%, 60%, and 70%. The results indicated that the mixed soil at low temperatures maintained a high moisture content, resulting in a slow evaporation rate. At low temperatures, the number of crack segments increased, and the block area decreased. The incorporation of sand could improve the porosity and increase the proportion of macropores, inhibiting crack formation. Adding sand could lengthen the overall drying period by prolonging the upward pathways and reducing the cross-sectional area of water migration. This study can help in analyses of crack formation of sandy slopes' topsoil.

Groundwater variation has a significant effect on the bearing capacity of sandy shallow foundations. Groundwater and capillary water in the shallow foundation would result in the various water distributions in the soil mass. Therefore, there are three types of water conditions in the shallow foundation. They are the total saturated, capillary-water-effect zone and dry soil. In this study, a physical mode experimental was developed to investigate the effect of groundwater variation on the deformation behavior under different loading conditions. The effect of water level and fluctuation times were examined by a novel setup with a water-pressure control system. A total of 10 group model tests were carried out. The results indicated that the relationship between water level height and foundation bearing capacity is negatively correlated. In addition, the numerical analysis was carried out to investigate the effect of water-level change on the bearing capacity of the foundation. The bearing capacity of the foundation decreases as the water-level cycles increase. The increase in the fluctuation range of the water level will decrease the bearing capacity of the foundation. The outcome of this study would be helpful to predict the bearing capacity of shallow foundations due to the change of the water level.

Jerusalem artichoke grows underground tubers that store fructans, primarily inulin, which are considered as prebiotics and functional dietary fibre with positive physiological benefits on human health. The aim of this study was to assess the yield and nutritional quality of Jerusalem artichoke tubers according to different cropping systems on dry sandy soils from Southern Romania. The experiments were carried out during 2018-2020 at the Research and Development Station for Plant Culture on Sands Dabuleni, using a randomized complete block design with three replications. The experimental combined factors applied were fertilization with plants density (5x2). After the tubers were harvested, their quality was evaluated using standard methods. The results suggest that Jerusalem artichoke crop has minimal requirements for fertilization and tolerates very well high plants density without affecting significantly the yield and the nutritional features analysed, respectively the contents in total dry matter, soluble dry matter, inulin, soluble carbo-hydrates and C vitamin. A significant positive correlation was determined between the soluble dry matter and soluble carbohydrates content. The assessed biochemical compounds displayed high values in both fertilized and unfertilized conditions and in both densities, showing that Jerusalem artichoke is a perennial crop with multifunctional high growing potential in marginal terrains usually improper for the conventional crops.

Mass transport in the soil is governed by water movement or flux due to diffusion mechanism and gravitational force. The diffusion is driven by spatial pressure difference where the water flows from low suction region to high suction region. The flow mechanism is applicable under unsaturated soil conditions. In gravitational flow, the water flow from high elevation to low elevation, vertically downward motion, and the rate of flow is depending on the soil water saturation level. In addition, under temperature gradient environment, the mass transport could be attributed by vapor transport by temperature gradient, which is in addition to the vapor transport under pressure suction gradient. Modeling water flow in soil is often limited to water flux mechanisms. This study aims to compare water vapor flux with water flux in the coastal soil in Terengganu, east coast of Peninsular Malaysia. The mechanisms of water vapor and water fluxes were quantified using mass transport equation. The results showed that water vapor flux was significant in value when compared to water flux under drier soil region. As the soil water content increases, the contribution of water vapor to the overall mass flux reduces and it becomes insignificant. Furthermore, soil that develops temperature gradient resulting in mass flux of water vapor in nearing dry soil has comparable mass transport as the liquid water flux by matric suction gradient, thus, it implies the inaccuracy of using Richard's equation utilization, management as well as conservation of coastal soil ecosystem.

The gob-side entry retaining (GER) technique, as the family member of the pillarless coal mining system, is becoming popular, mainly attributed to its high resource recovery rate and significant environmental benefits. Seeking cost-effective backfill material to develop the roadside backfilling body (RBB) is generally a hot topic for coal operators and scholars. Except for its relatively high cost, the other shortcoming of the widely used high-water backfill material is also obvious when used in arid, semi-arid deserts or Gobi mining areas lacking water. The modified high-water backfill material (MBM) mixed with aeolian sand was recently developed as an alternative to conventional backfill materials. Some critical parameters affecting both the physical and mechanical properties of the MBM, including the amount of the aeolian sand and water-to-powder ratio of the high water-content material, have been experimentally investigated in the present research. Test results showed that the MBM featured high early strength and bearing capability after a large post-peak deformation. In particular, the adjustable setting time of the MBM through changing the amount of sand widens its application in practice. Unlike the high-water backfill material, the MBM is a typical elastoplastic material; the stress-strain curves consist of pore compression, elastic deformation, yielding, and total failure. Note that both the peak and residual strength of the MBM increased as the doping amount of aeolian sand increased, which is probably because of the impacted aeolian sand and the uniform reticular structure of the ettringite in the MBM. Compared with the high-water backfill material, only limited cementitious material and water resources are requested to cast the RBB, which provides more economical and environmental benefits for the application of the GER technique in the arid, semi-arid deserts or the Gobi mining areas.

Dry playa surfaces can be extremely vulnerable to disturbance which breaks their surface crusts resulting in increased aeolian sand and dust emissions. Trampling by livestock and motor vehicles is an important source of this disturbance. The Hamoun Lakes in the Sistan region of Iran are a major source area of dust storms which are causing damage to infrastructure and communities. This study performed portable wind tunnel tests of controlled surface disturbance by animals (cow, sheep) and motor vehicles (automobile, motorcycle) on a silty playa surface of Hamoun Saberi lake. The aim of this study was to assess the effect of different levels of trampling and disturbed surfaces by both vehicles and livestock on dust emission at wind speeds of 6 and 12 m s(-1). A significant increase of sediment emission was found with increased number of passes of vehicles and livestock and the degree of surface disturbance, more so at the high wind speed (12 m s(-1)). No significant differences were observed between a 10-20% disturbance level and an undisturbed surface, but statistically significant differences became apparent when disturbances reached 50-60% to 90-100% compared to undisturbed surfaces. Greater emission rates were reached by disturbances provided by automobile and cow compared to motorcycle and sheep, indicating greater trampling effects of automobile and cow likely related to greater weight and larger footprint. The automobile was the most surface-destructive of the four anthropogenic disturbances, providing emission in a lower number of passes compared to the motorcycle, cow and sheep. Better management of vehicle and livestock allocation on playas subject to disturbance, such as the Hamoun Lakes, will be a useful strategy to reduce disturbance and the frequency and intensity of dust storms.

Marginal sandy soils are frequently characterized by low fertility, low organic matter, moderate to high acidity and low cationic exchange capacity, limiting the options of smallholding farmers for various crops. To investigate the impact of the sowing time on grain yield, yield components, protein and oil content of peanuts cultivated in marginal sandy soils in Southern Oltenia, Romania, a bifactorial experiment in a randomized complete block design with three replications was conducted during 2015-2017 at the Research Development Station for Plant Culture on Sands Dabuleni. The first factor was sowing time (the 25th April as early sowing and the 5th May as late sowing) and the second factor was peanut cultivar (Dabuleni, Viorica, Viviana). According to the results of the experiment the sowing time had significant impact on the pods number per plant, the production of pods and the grain oil content. Analyzing the interaction between the sowing time and the cultivar there were significant differences only in the pod number per plant in 2015 and the production of pods in 2016. In all peanut's genotypes studied, early sowing led to higher yields of pods compared to late sowing, probably due to the shortening of the vegetation period of the crop by late sowing on the 5th May, which led also to less dry matter and lower oil content accumulated in peanut grains. Therefore, the results suggested that early sowing time is the most recommended for peanuts growth and quality yield in sandy marginal areas.

The diversity of soils and climate in Brazil imposes the need to evaluate the adaptation of fodder species to soil and climate conditions to guide producers and technicians in choosing the best alternatives for their region. The objective of this study was to evaluate and identify fodder cultivars for pasture and soil cover with tolerance to drought and high production in the sandy soils of southern Bahia, Brazil. The performance of 29 commercial cultivars of perennial and annual tropical forage species was evaluated in six cuts in 2019 and 2020. The green and dry mass yield per cut and the daily dry matter accumulation rate were evaluated considering the periods of water surplus and deficit and the drought tolerance index for each cultivar was estimated. Grass and legume cultivars showed differences in establishment, yield in the water surplus, and in the re-establishment after the water deficit. Based on the values of the drought tolerance index and in the dry mass daily yields before and after the water deficit, the cultivars adapted and indicated for regional continuous grazing were Xaraes, Marandu, Massai, Tanzania, Paiaguas, and Zuri, in that order. The grasses B. ruziziensis and B. decumbens were indicated for use as cover plants after the harvest due to their high capacity of establishment and short-term production. The annual and perennial legume plants were also indicated for cover, and the combination of cultivars and their potential for straw in direct planting or use in integrated systems still need to be validated.