Site Conditions Research Articles

A comparative study of using geophysical methods for imaging subsurface voids of various sizes and at different depths

Subsurface voids pose significant geohazards, underscoring the need for their timely detection in order to mitigate the associated hazard. We report on a field study aimed at the comparative assessment of electrical resistivity tomography (ERT), seismic refraction tomography (SRT), and the multichannel analysis of surface waves (MASW) for void mapping in karstic regions. The field surveys were conducted at a site in central Texas, of typical karstic geomorphology, and involved the co-located deployment of ERT, SRT and MASW arrays. Post-surveying, boreholes were drilled at select locations for verification purposes. It is shown that MASW demonstrated limited ability to resolve voids due to its inherent theoretical limitations. In contrast, ERT revealed high-resistivity air-filled zones, and low-resistivity soil-filled regions, which aligned well with post-survey borehole logs, although deeper voids remained largely undetected. SRT clearly delineated voids through velocity reductions, but smoothing effects overestimated void velocities. Using ERT and SRT jointly provided improved void characterization compared to single-method-based interpretations, with ERT determining void type and SRT delineating boundaries. Despite the relative success of the joint ERT-SRT application, it is evident that without the corroboration provided by invasive testing, definitive void localization and characterization under arbitrary site conditions remains elusive.

Application of non-stationary shear-wave velocity randomization approach to predict 1D seismic site response and its variability at two downhole array recordings

Accounting for uncertainties in seismic site response is crucial to improving the performance of one-dimensional (1D) ground response analyses (GRAs) at downhole array recording sites. In addition to site effects, uncertainties in 1D-GRAs can also be contributed from the seismic source and/or path. Though often representing not more than one percent of the distance (path) from the source, site conditions are known to have an enormous influence on ground shaking. In this study, we focus on the site shear-wave velocity (VS) structure, which is the main ingredient for estimating the variability of site response. As such, VS can manifest aleatory uncertainties related to the effects of small-scale spatial heterogeneities within the near surface, thus VS can substantially modify ground shaking during earthquakes. We apply a novel VS randomization approach to propagate the small-scale heterogeneities of VS to estimate seismic site response within a non-stationary probabilistic framework. The randomization approach generates samples of VS profiles that are used to perform several 1D-GRAs and obtain an averaged site response and related variability. The proposed method is implemented on data recorded at two downhole array sites with different subsurface soil conditions: a soft soil site on Treasure Island (California, United States of America) and a rock outcrop site in Cadarache (South-East France). We show that synthetic surface-to-borehole transfer functions from 1D-GRAs provide an acceptable fit to the empirical transfer functions from low-motion earthquake records and succeed in reproducing most of the site-specific seismic response variability. The remaining mismatch between transfer functions is likely due to insufficient precision on the seismic bedrock and the impedance contrast. The variability in site response is discussed with emphasis on the role of VS small-scale heterogeneities, attenuation, and input motion incidence angle in ground motion variability for the site and soil conditions at both locations.

Case Study: Advanced Technology Underpins Efficiency and Climate-Related Goal Gains

_ Today’s gas-compression operators are under increasing pressure to reduce greenhouse gas (GHG) emissions. Fortunately, multiple technologies are available that can support that objective while enabling operators to move more gas cost-effectively. Embracing such advancements can positively impact a reduced-carbon future without compromising operational efficiency or profitability. To choose the right technologies for a gas-compression package, it’s critical for operators to have a clear understanding of their business and GHG emissions-related goals. Operators also need clarity concerning the impact of evolving requirements on total cost of ownership (TCO) as well as potential financial ramifications. Producing more gas at a lower cost with lower GHG emissions is possible with new technologies. Operators can support their success by choosing the right engine driver for a gas-compression package based on their unique needs and site conditions. It’s critical to consider an engine’s power density and TCO, as that informs an operator’s selections and can lower a gas-compression package’s operating cost in terms of dollars per thousand cubic feet ($/Mcf) of gas throughput. An engine, such as the Cat G3600 A4 Gen 2, that can deliver a 10% power increase compared to the previous model can allow operators to use fewer engines to perform the same amount of work. This advantage can lower capital requirements, reduce operating expenses, and decrease fuel consumption. Fewer engines operating in the field may also contribute to lower GHG emissions. Modernizing Existing Assets Operators prioritize flexibility, durability, and lower TCO. They can support those objectives by choosing an engine platform that allows performance upgrades across the life of the engine. This enables operators to apply advanced technology in their existing fleet year after year without incurring the substantial cost of purchasing a new engine. Engine upgrade kits offer operators an option to maximize and modernize active assets in a streamlined way, as the upgrades can be applied conveniently and cost-effectively at the time of a scheduled overhaul to minimize disruption. For example, by using an upgrade kit for an A4 Gen 1 engine model referenced above, operators can lower volatile organic compounds up to 32%, formaldehyde up to 24%, carbon monoxide up to 13%, methane emissions up to 33%, and total GHG emissions up to 5% on a grams per brake horsepower-hour (g/bhp-hr) basis* while saving the traditional capital expenditure of a new engine. (*Site conditions: Same power level between the G3600 A4 Gen 1 and Gen 2, 85MN, 905 BTU/scf, 100% load, 25°C ambient, 500-ft altitude.) Such updates are relatively cost neutral when applied as part of a scheduled major overhaul and require minimal or no change to the compression package. This makes upgrade kits a wise choice to ensure equipment keeps pace with industry demands.

The influence of forest types including native and non‐native tree species on soil macrofauna depends on site conditions

AbstractThe ongoing climate change calls for managing forest ecosystems in temperate regions toward more drought‐resistant and climate‐resilient stands. Yet ecological consequences of management options such as planting non‐native tree species and mixing coniferous and deciduous tree species have been little studied, especially on soil animal communities, key in litter decomposition and pest control. Here, we investigated the taxonomic and trophic structure of soil macrofauna communities in five forest types including native European beech (Fagus sylvatica), range‐expanding Norway spruce (Picea abies) and non‐native Douglas fir (Pseudotsuga menziesii) as well as conifer‐beech mixtures across loamy and sandy sites in northern Germany. Abundance of primary decomposers (feeding predominantly on litter) was high in Douglas fir and beech forests, benefiting from less acidic soil and more favorable litter resources compared to spruce forests, while secondary decomposers (feeding predominantly on microorganisms and microbial residues) reached highest densities in spruce forests. Differences in abundance and species richness among forest types generally varied between regions and were most pronounced in Douglas fir of the sandy region. However, trophic guilds differed more between regions than between forest types, indicating that environmental factors outweigh the importance of forest type on soil macrofauna communities. The analysis of stable isotopes (δ15N and δ13C values) supported the general robustness in trophic position of macrofauna trophic guilds against variations in forest types and regions, but indicated reduced detrital shifts and food‐chain lengths in coniferous compared to European beech forests with mixtures mitigating these effects. Overall, for evaluating consequences of future forest management practices on the structure and functioning of soil animal communities, regional factors need to be considered, but in particular at loamy sites the taxonomic and trophic structure of soil macrofauna communities are resistant against changes in forest types.

Divergent Responses of Fir and Pine Trees to Increasing CO2 Levels in the Face of Climate Change

AbstractUnderstanding the response of forests to the increases in atmospheric CO2 (ca) is fundamental to implementing innovative management strategies and for assessing impacts on the global carbon and water cycles. Here, we explored correlations between ecophysiological traits and climate variability that influence changes in stable isotope carbon and oxygen (δ13C and δ18O) of tree‐rings. We present these relationships between species of the contrasting genera Abies and Pinus, along a latitudinal transect encompassing different biogeographical regions in North America. We also tested if the rate of intrinsic water‐use efficiency per unit of ca (dW/dca) during two periods (1890–1965 vs. 1966–2016), for fir and pine were different and indicated acclimation to ca increases. We hypothesize that, spatially and temporally, the divergent responses among species to carbon and oxygen isotopes and dW/dca are influenced by the site conditions and the historical increases in ca. From our results, we show that fir and pine species will behave physiologically different as global warming progresses. Firs are more responsive to atmosphere vapor pressure deficit along different geographical zones. The survival of forests species under climate change will rely on the response to water stress and species' traits that influence the regulation of dW. Finally, we want to highlight the concept of “progressive resource limitation” of soil water and nutrients, previously proposed by other authors, that likely indicate fir species that inhabit moister sites will benefit more from increased ca than pine, but this positive effect is likely transitory as global warming increases.

Evaluation of Noah-MP Snow Simulation across Site Conditions in the Western United States

Abstract Quantifying spatiotemporal variability in snow water resources is a challenge especially relevant for regions that rely on snowmelt for water supply. Model accuracy is often limited by uncertainties in meteorological forcings and/or suboptimal physics representation. In this study, we evaluate the performance and sensitivity of Noah land surface model with multiparameterization options (Noah-MP) snow simulations from ten model configurations across 199 sites in the western United States. Nine experiments are constrained by observed meteorology to test snow-related physics options, and the 10th experiment tests an alternative source of meteorological forcings. We find that the base case, which aligns with the National Water Model configuration and uses observation-based forcings, overestimates observed accumulated snow water equivalent (SWE) at 90% of stations by a median of 9.6%. The model performs better in the accumulation season at colder, drier sites and in the melt season at wetter, warmer sites. Accumulation metrics are sensitive to model configuration in two experiments, and melt metrics, in six experiments. Alterations to model physics cause changes to median accumulation metrics from −13% to 2.3% with the greatest change due to precipitation partitioning and to melt metrics from −10% to 3% with the greatest change due to surface resistance configuration. The experiment with alternative forcings causes even greater and wider-ranging changes (medians ranging from −29% to 6%). Not all stations share the same best-performing model configuration. At most stations, the base case is outperformed by four alternative physics options which also significantly impact snow simulation. This research provides insights into the performance and sensitivity of snow predictions across site conditions and model configurations. Significance Statement The purpose of this work is to evaluate the performance and sensitivity of a land surface model’s simulation of snow across site conditions and in response to different model configurations. This is important because estimating snow distribution is a challenge especially relevant for regions that rely on snowmelt for water supply. While land surface models can provide useful large-scale estimates, they are often limited by uncertainties in forcings and/or suboptimal physics representation. The results, which show varying model behavior across geography, climate, vegetation types, and model configurations, highlight inadequacies in model physics representation, emphasize the need for accurate meteorological forcings, and suggest that customizing model configurations to the unique characteristics of the domain could yield more accurate and useful results.

On the Possibility of Controlling the Strength of Soil Cement Elements by the Strength of Soil Cement Pulp

The issue of the possibility of monitoring the results of work on jet cementation by testing the pouring pulp is being considered. A comparison of the results of the strength of the hardened ground cement pulp and the strength of cores from the corresponding ground cement elements made using various technologies with different cement consumption is presented.The results obtained in the conditions of a single construction site composed of soft-plastic loams make it possible to recommend the proposed assessment methodology of the strength of the soil cement to the physician without expensive work on drilling control wells. It is possible to conduct similar studies in different geological conditions.

Vineyard cover crop management strategies and their effect on soil properties across Europe

AbstractVineyard soils are often of inherently poor quality with low organic carbon content. Management can improve soil properties and thus soil fertility. In European wine‐growing regions, a broad range of inter‐row management strategies evolved based on specific local site conditions and the varying effects of management intensities on soil, water balance, yield and grape quality. Accordingly, there is a need to investigate the effects of locally common cover crop management strategies and tillage intensity on soil organic carbon content and soil physical parameters. In this study, we investigated the impact of the most common inter‐row management practices in Austria, France, Romania and Spain. In all countries, we compared paired sites. Each site with cover crops and inter‐row management of low intensity was compared with one site with (temporarily) bare soil and high management intensity. All studied sites with cover crops and low management intensity, except those in Spain, had higher organic carbon contents than the paired more intensively managed vineyards. However, the highly water‐limited Spanish vineyards with temporary cover crops had lower organic carbon contents than the paired sites with bare soil. Sites with more organic carbon had better results for bulk density, percolation stability (PS), hydraulic conductivity and available soil water, with soil hydraulic parameters being less pronounced than others. Country comparison of inter‐row weed control systems showed that PS was particularly low in sampled vineyards in Romania and Spain, where weed control is based on intensive mechanical tillage. Alternating management systems with tillage every second inter‐row showed a decrease in soil structure compared with permanent green cover. Thus, inter‐row management with cover crops and reduced tillage increases soil organic carbon content and improves soil structure compared with bare soil management. If local constraints, such as water scarcity, do not allow year‐round planting, alternating inter‐row management with several years of alternating periods may be an option to mitigate those adverse effects. However, negative impact on the soil structure occurs with the very first tillage operation, whereas negative effects on the carbon balance only appear after long‐term use of tillage.

Shear-Wave Velocity Data Assists Modeling for Offshore Windfarm Development

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper OTC 35354, “Pseudo-3D Underwater Multichannel Analysis of Surface Waves for Offshore Windfarm Development,” by Stephan Unterseh and Luis McArthur, TotalEnergies, and Edouard Mouton, SismOcean. The paper has not been peer reviewed. Copyright 2024 Offshore Technology Conference. _ In the course of a research and development (R&D) project dedicated to quantitative ground modeling, underwater multichannel analysis surface-wave (UMASW) data were acquired within an offshore windfarm area currently in development in the North Sea. The goal of the project described in the complete paper was to test the added value of the shear wave velocity (Vs) interpreted from the UMASW, particularly as a propagation tool of geotechnical information. While UMASW, together with seismic refraction, is regularly used to characterize the ground for burial or trenching purposes, it appears also to bring valuable design parameters for offshore wind turbine foundations. Introduction To investigate the value of Vs in the performance of quantitative ground modeling studies, an internal R&D initiative was launched aimed at acquiring Vs data and the associated uncertainties of foundation depth of an offshore windfarm currently in development. These data will be tested at a later stage for the propagation of geotechnical parameters used in foundation design. The acquisition consisted of obtaining Vs data through UMASW methodologies around two distinct geotechnical boreholes and along a corridor tying the two areas. The UMASW commonly is used in combination with seismic refraction to perform burial assessment analysis of cable or pipeline or to characterize ground conditions before performance of horizontal deviated drilling. Thus, the data acquisition did not require extensive hardware development. A unique pseudo-3D processing technique nevertheless was implemented to allow for 3D data visualization and ground characterization. Site Conditions The selected site lies in the North Sea in water depths ranging from 20 to 30 m. The area was first investigated with standard geophysical techniques. Preliminary geotechnical investigation included 6-m-deep vibrocores and 60-m-deep drilled boreholes, with alternating cone penetration tests and push sampling and coring. P-S logging also was performed at key geotechnical locations to gather 1D primary wave velocities (Vp) and Vs. The seabed generally consists of a thin cover of Holocene dense sand, occasionally with boulders, overlying quaternary subglacial formation deposits, including moraine, gravelly sand, and clays of variable thicknesses. The bedrock is generally Jurassic and includes dense sand; hard clay; weak claystone; and, locally, strong limestone bands. The test locations were selected within the coverage of the geophysical data set in areas where variable lithologies occur and where the seabed was found free of boulders and outcrops because these are detrimental to UMASW acquisition. The lithology of the two boreholes performed within the test area is indicated in Table 1 of the complete paper.

Ecosystem services in mountain pastures: A complex network of site conditions, climate and management

Mountain pastures offer a multitude of ecosystem services (ES) such as fodder for ruminants, habitat for pollinators, climate change mitigation, aesthetic landscape for recreation, and biodiversity conservation. We aimed at analysing to which extend these ES are influenced by small-scale gradients of climate, site conditions and management – and to disentangle relationships among ES and the factors influencing them. Therefore, we quantified ES on six mountain summer farms in two contrasting regions in Switzerland: the Northern Alpine Foothills (lower elevation, higher precipitation, calcareous bedrock) and the Eastern Central Alps (higher elevation, lower precipitation, silicious bedrock). We measured six ES indicators (forage quantity, forage quality, carbon storage, colour abundance, resources for pollinators, plant diversity) and related them to explanatory factors of climate (temperature and precipitation), site conditions (soil fertility, soil acidity, terrain slope) and management (local grazing intensity, remoteness) in 66 study plots, i.e., 11 per farm. A holistic picture of the complex relationships among these factors was drawn by various statistical approaches: allometric line fitting, variance partitioning, and structural equations modelling. We found a huge heterogeneity of ES indicators and explanatory factors on each farm: the variability within farms was even higher than between regions. Variance partitioning and structural equations modelling demonstrated strongest influence of climate and site conditions and revealed trade-offs among ES indicators: High forage quantity and quality were associated with low plant diversity and grassland aesthetics, whereas diversity, aesthetics and pollinator resources were positively correlated with each other. ES indicators were explained by a range of climatic and topographic factors: High precipitation reduced plant diversity, whereas temperature increased forage quantity and quality; slope reduced soil fertility, forage quantity, forage quality and carbon storage; soil fertility in turn increased forage quantity; the farther away a pasture was from the main farm building, the lower was the forage quantity and the higher the plant diversity. Although allometric relations among local grazing intensity and ES indicators were strong, the direct influence of the management factors measured on ES was surprisingly small: Cattle preferred areas of high forage quantity and quality, and carbon storage was higher in these areas. On the other hand, places less visited by cattle offered more pollinator resources, and showed higher aesthetics and plant diversity. Trade-offs among ES prevent the realisation of all ES at the same place, but heterogeneity of mountain pastures allows to realise a broad bundle of contrasting ES on each individual summer farm.

Antimicrobial Activity of Senna didymobotrya and Thunbergia alata Plant Extracts Against Selected Bacterial Clinical Isolates from Kericho Referral Hospital in Kenya

Bacterial infections are distributed worldwide and cause deadly infectious bacterial diseases such as skin, soft tissue and respiratory tract infections, meningitis, and tuberculosis. Bacterial infections are very common and can be easily acquired since bacteria are ubiquitous. It has challenged modern healthcare providers; conventional drugs are costly and have side effects. Therefore, alternative remedies that are easily available, affordable, and effective are needed. This study was carried out to determine the antimicrobial activity of Senna didymobotrya and Thunbergia alata crude plant extracts against Staphylococcus aureus, Streptococcus pyogenes and pseudomonas aeruginosa common in Kericho County. Plant leaves of the two plants were sourced from two sites (Bomet and Kabianga), dried, milled into powder and solvent extracted using hexane, dichloromethane: methanol ratio (1:1) and methanol. Phytochemicals present in each plant extract were evaluated using standard laboratory procedures. Antimicrobial sensitivity testing, Minimum Inhibitory Concentrations (MICs) and Minimum Bactericidal Concentration (MBC) were determined. Discs impregnated with standard antibacterial drugs were used as positive control. Leaves of T. alata and Senna didymobotrya collected from Bomet contained 7.41% and 10.4% while those from Kabianga contained 8.07% and 17.71% of extracts respectively, suggesting that site conditions do not influence the percentage of extracts. Leave extracts of S. didymobotrya and T. alata were found to be rich in alkaloids, flavonoids, terpenoids, glycosides and tannins irrespective of plant collection site, solvent of extraction. S. didymobotrya and T. alata plant extracts significantly inhibited growth of the exposed microbes in the following order: S. aureus, ≥S. pyogenes and≥ P. aeruginosa bacteria in comparison with commercial antibiotics (penicillin, chloromphenical, and erythromycin). The MIC values of the isolates ranged from 20×10-3 mg/ml to 4.8 ×10-3 mg/ml. However, bacterial inhibition by plant extracts showed re-growth of S. pyogenes after 36 hours, suggesting bacteriostatic nature. These results suggest that S. didymobotrya and T. alata leaves contain significant amounts of alkaloids, flavonoids, terpenoids, glycosides and tannins hence can be used as traditional medicine to manage S. aureus, S. pyogenes and P. aeruginosa bacteria found on human skin

Ground-motions site and event specificity: Insights from assessing a suite of simulated ground motions in the San Francisco Bay Area

This article presents the results of a research that is part of a larger collaborative effort between the Lawrence Berkeley National Laboratory and the Pacific Earthquake Engineering Research Center, funded by the US Department of Energy Office of Cybersecurity, Energy Security and Emergency Response. The main objective of this study is to assess a suite of near and far-field simulated ground motions obtained from 20 realizations of an M7 Hayward Fault earthquake in the San Francisco Bay Area, California USA, and inform the selection of rupture simulation parameters leading to strong motions. To this aim, comparisons are conducted with NGA-W2 and directivity ground-motion models and a selected population of records. An archetypal steel moment-resisting frame is utilized to assess infrastructure response distributions. The analyses carried out for each simulated event and subdomain with consistent properties in terms of shallow shear-wave velocity proved to be instrumental for better interpreting the differences between simulated motions and empirical models. The main reasons identified for variances between simulations and empirical relationships included (1) directivity effects fully captured by the simulations across the full breadth of rupture models; (2) site vicinity to ruptures that incorporate large-slip patches, particularly if these are in the forward-directivity direction; and (3) presence of geologic structures that can “trap” seismic waves and produce ground motions with large amplitude and long signal duration. The analyses carried out in this work provide a path for interpreting ground-motion site and event specificity obtained from a suite of physics-based simulations, differing only in the rupture model characterization, to inform the selection of simulation scenarios for site-specific engineering analyses under strong excitations. Evidence from this work points to the possibility that current hazard models may underestimate ground-motion intensities in areas where the combined effect of directivity and site conditions results in large ground-motion amplitudes.

A Real-World Pharmacovigilance Study of the FDA Adverse Event Reporting System Events for Trametinib.

This research investigates adverse drug events (ADEs) linked to trametinib, utilizing data from the FDA Adverse Event Reporting System (FAERS) database, covering the period from Q2 2013 to Q4 2023. We gathered data on ADEs associated with trametinib from the second quarter of 2013 to the fourth quarter of 2023. After standardizing the data, we applied various analytical methods to quantify signals, including the reporting odds ratio (ROR), proportional reporting ratio (PRR), Bayesian Confidence Propagation for Neural Networks (BCPNN), and multi-item gamma Poisson shrinker (MGPS). In our examination of 2200 ADE reports with trametinib cited as the primary suspect, we identified 191 adverse reaction terms across 23 system organ classifications. The most frequently reported classifications were general disorders and administration site conditions, with 1254 cases (ROR 0.83, PRR 0.85, IC -0.23, EBGM 0.85), followed by neoplasms (benign, malignant, and unspecified, including cysts and polyps) with 802 cases (ROR 3.59, PRR 3.32, IC 1.73, EBGM 3.32), and investigations with 794 cases (ROR 1.74, PRR 1.66, IC 0.73, EBGM 1.66). Notably, this study also uncovered previously unlabeled adverse reactions such as cheilitis, lobular panniculitis, ulcerative keratitis, and stridor. While trametinib provides therapeutic advantages, it is associated with several potential adverse reactions. It is crucial for healthcare providers to closely monitor patients for symptoms such as cheilitis, lobular panniculitis, ulcerative keratitis, stridor, and other adverse events (AEs) during treatment.

Simulating the near-field dynamic plume behavior of disposed fine sediments

Projections of the effects of fine sediment disposals, relevant for managed estuaries and tidally influenced coastal areas, are typically based on numerical far-field models. For an accurate consideration of the disposal itself, near-field models are often needed. The open source near-field model, PROVER-M, simulates the relevant processes of the physics based, dynamic behavior of disposed fine sediments in coastal waters and is applied in this study. First, new small scale laboratory experiments of instantaneous disposals are presented, documenting the dynamic behavior of fine material disposed in shallow waters. Second, results of the PROVER-M model are shown for disposals in three different settings: (1) a field-scaled study complementary to the laboratory set-up, (2) a parametric study of sequentially varied model input and (3) a far-field model coupling for estimation of the PROVER-M impact. By comparing results of the laboratory experiments to the PROVER-M model, the physical behavior of PROVER-M is successfully validated. The impact of the ambient setting and dredged material parameters is evaluated by the PROVER-M simulations, where the results show non-linear, complex interdependencies of the input parameters on disposal properties in dependence of ambient site conditions and material composition. In this context, limits of the model application are assessed and critically discussed. Finally, an exemplary coupling to a far-field model based on a real set of disposals in the tidally influenced Weser estuary (Germany) illustrates the potential impact of PROVER-M for assessing far-field suspended sediment concentration (SSC), with increased maximum SSC values of up to 10%.

Trees support functional soils in a dryland agricultural area

Trees provide multiple ecosystem services such as carbon sequestration, hydrological regulation and habitat for arboreal animals. However, they are often removed to support agricultural enterprises. Despite the importance of tree remnants, we know relatively little about how soils differ across sites of varying condition. Here, we describe a study where we examined the relative effects of trees, compared with unvegetated interspaces, on soil functions in remnant patches at sites in good and poor condition in two eucalypt communities in an irrigation area in eastern Australia. We found that, in general, carbon and nutrient cycling were relatively greater beneath trees, and in surface soils, but there were no clear trends in relation to site condition. The values of most soil attributes (e.g., soluble and exchangeable cations, nitrogen, phosphorus) were greater beneath trees, indicating strong fertile island effects in both communities. Overall, our study confirms the importance of trees in remnant patches in agricultural landscapes, particularly those in sites of poor condition. It also suggests that soil processes may still be relatively intact, even in sites in poor condition. Our study reinforces the need to protect trees in remnant woodland reserves to maintain critical ecosystem functions related to nutrient retention. These remnants are important for achieving sustainable management of agricultural systems.

Design response spectrum based on shock-waveform decomposition method

This study applies the shock-waveform (SW) decomposition method, originally developed for mechanical shock analysis, to earthquake ground motions. It reveals a general shape similarity between the envelope of the Pseudo-Spectral Accelerations (PSAs) of SW decomposed components and the PSA of the corresponding ground motion. Based on this similarity, a novel method to determine the characteristic period Tg, the long-period transition period TD, the shape correction period Tβ, and the Design Response Spectrum (DRS) is proposed and evaluated. New methods to determine Tg, TD and Tβ from the signal decomposition perspective are integrated into the normalized DRS in Eurocode 8–2022, enabling the construction of the normalized DRS based on SW method (SWDRS). Furthermore, simple ground motion attenuation regression equations are derived to relate the parameters (Tg, TD, Tβ) and the corresponding spectral ordinates of the normalized SWDRS model with seismic magnitude and site conditions. The SWDRS model is validated by randomly selecting two sites in United States. For each site, the SWDRS is determined by using the attenuation regression equations and the DRS spectral plateau value from the official seismic hazard map. Comparisons between the SWDRS, the latest local DRS, and the severest historical PSA recorded at the specific site demonstrate that the SWDRS provides more accurate spectral values over intermediate- and long-period ranges for structural seismic design.

Identifying the effect of subgrade layer thickness of soil stabilized with waste foundry sand and fly ash on bearing capacity

The issue of subgrade soil often involves unstable soil properties, such as low bearing capacity, susceptibility to expansion and shrinkage, and vulnerability to erosion and deformation due to traffic loads and weather conditions. Unstable subgrade soil can cause various infrastructure problems, including cracks, settlement, and damage to road surfaces. Therefore, stabilizing subgrade soil is an important step to ensure the reliability and longevity of highways. One effective and sustainable method for subgrade soil stabilization is by utilizing local waste materials. The use of local waste materials such as fly ash (FA) and waste foundry sand (WFS) not only improves the physical and mechanical properties of the soil but also helps reduce environmental impact by repurposing pollutants. This study aims to analyze the effect of the thickness of subgrade layers stabilized with FA and WFS on bearing capacity. The initial stage includes examining the physical and mechanical properties of natural soil and soil stabilized with FA and WFS. The waste content used is 9 % FA and 15 % WFS by dry weight of the soil. Subgrade modeling was conducted using a steel box measuring 60×60×60 cm with a soil thickness of 30 cm. Load testing was carried out on 5 layer variants that had undergone 4 days of curing. The study results found that the ultimate bearing capacity (qult) of 890 kPa was produced by the V4 layer, which is a subgrade with a 30 cm thick layer of soil stabilized with FA and WFS at a settlement of 6 mm. The bearing capacity ratio of 2.87 means that the subgrade with a 30 cm thick layer of soil stabilized with FA and WFS experienced an improvement in bearing capacity of 2.87 times that of the subgrade with untreated soil material. The results obtained can be applied in practice to the local geotechnical conditions of the project site in West Java, including natural soil properties and seasonal changes

Underestimation of strong wind speeds offshore in ERA5: evidence, discussion and correction

Abstract. Offshore wind power plants have become an important element of the European electrical grid. Studies of metocean site conditions (wind, sea state, currents, water levels) form a key input to the design of these large infrastructure projects. Such studies rely heavily on reanalysis datasets which provide decades-long model time series over large areas. In turn, these time series are used for assessing wind, water levels and wave conditions and are thereby key inputs to design activities such as calculations of fatigue loads and extreme loads and platform elevations. In this article, we address a known deficiency of one these reanalysis datasets, ERA5, namely that it underestimates strong wind speeds offshore. If left uncorrected, this poses a design risk (high and extreme wind, waves and water level conditions are underestimated). Firstly, comparisons are made against CFSR/CFSv2 reanalyses as well as high-quality wind-energy-specific in situ measurements from floating lidar systems. Then, the ERA5 surface drag formulation and its sea state dependency are analysed in detail, the conditions of the bias identified, and a correction method is suggested. The article concludes with proposing practical and simple ways to incorporate publicly available, high-quality wind energy measurement datasets in air–sea interaction studies alongside legacy measurements such as met buoys.

Diameter growth models and performance of 100 tropical tree species in silvicultural trials in Brazil

Projects of reforestation for sustainable production of tropical timber and for nature-based solutions must be based on reliable growth models. However, there is still a big gap in knowledge about the growth in diameter for native and exotic tropical timber species. Here, we used diameter growth data from 100 tropical tree species in silvicultural experiments established from the late 1970s to the early 1990s in the Vale Natural Reserve in the north of Espírito Santo state, Brazil. Plantations were periodically measured, usually over 20–30 years, which allowed us to produce growth models for all species and recommend those that can help boost silviculture in Brazil. We also used the data to test a large set of tree species against the same set of models, to assess model’s performance. Among 71 native species studied, 31 % showed slow growth (MAI < 0.70 cm/yr), 40 % medium growth (0.70≤ MAI < 0.97 cm/yr) and 29 % high growth (MAI ≥ 0.97 cm/yr), while 47 % of the 29 exotic species showed high growth rates. Based on our analysis, we recommend the use of Korf, Levakovik II, Hossfeld IV, and Levakovic III models for growth studies, because they showed a better fit for most species or because they were plausible competitor models. Even though many species have shown a great performance for silvicultural projects, more experimental trials must be established in different site and management conditions, to fully explore the silvicultural potential of these tropical timber species.

Adverse events associated with inclisiran: a real-world disproportionality analysis based on the FAERS database

ABSTRACT Background Randomized clinical trials have reported some safety profiles in inclisiran, but adverse events in real-world remain insufficient. We aim to evaluate the safety of inclisiran in real-world by collecting the data from the FDA Adverse Event Reporting System database. Methods Disproportionality analysis was performed by utilizing both Frequency method and Bayesian method to mine adverse event signals of inclisiran. A positive signal was deemed significant when adverse event met the criteria of the aforementioned methods simultaneously. Results We gathered a total of 2309 adverse event reports. Among these cases, adverse events were more common in females and ≥ 65 years age group. After data analysis, 51 positive signals from 11 system organ classes were identified, involving “Musculoskeletal and connective tissue disorders,” “General disorders and administration site conditions,” “Gastrointestinal disorders,” etc. At the preferred term level, the top three frequently reported adverse events were arthralgia, injection site pain and myalgia. We also found some uncommon but significantly strong adverse event signals (bladder discomfort and sinus pain) which should be taken prudently. Conclusions In this study, we analyzed the real-world adverse events of inclisiran more comprehensively and reported some new adverse events, hoping that can offer more safety information for clinical medication.