Wet Conditions Research Articles

Anti-swellable, stretchable, self-healable, shape-memory and supramolecular conductive TA-based hydrogels for amphibious motion sensors

Conductive hydrogel endures as an ideal candidate for flexible electronic devices. However, conventional conductive hydrogels cannot incorporate superior sensitivity under low deformation, biocompatibility and underwater sensing into one system, which widely obstructs their applications in an aqueous environment. Herein, we designed a supramolecular conductive poly(vinyl alcohol) (PVA) and tannic acid (TA) based PVA/TA hydrogel. Due to the effective hydrogen bonding between PVA and TA, the hydrogel possesses some unique properties, including anti-swelling, stretching, self-healing and shape-memory. The PVA/TA supramolecular hydrogel demonstrates an excellent electrical performance where the conductivity and gauge factor (GF) are obtained at 5.5 × 10-4 S/cm and 1.3 in dry and 5.0 × 10-4 S/cm and 1.2 in wet conditions, respectively. The multifunctional hydrogel manifests excellent mechanical properties, where the maximum tensile strength of the hydrogels is 700 kPa at an elongation of 4700 %. Additionally, the hydrogel possesses excellent shape-memory and self-healable properties. Moreover, the hydrogel depicts outstanding biocompatibility, anti-swellable properties and exerts long-term stability underwater to detect human motions. Based on excellent anti-swelling and stability, high electrical conductivity and extraordinary stretching capability, the hydrogels may consider as promising candidates for applications in amphibious motion sensors.

Aerosol influence on cloud macrophysical and microphysical properties over the Tibetan Plateau and its adjacent regions.

This study uses aerosol optical depth (AOD) and cloud properties data to investigate the influence of aerosol on the cloud properties over the Tibetan Plateau and its adjacent regions. The study regions are divided as the western part of the Tibetan Plateau (WTP), the Indo-Gangetic Plain (IGP), and the Sichuan Basin (SCB). All three regions show significant cloud effects under low aerosol loading conditions. In WTP, under low aerosol loading conditions, the effective radius of liquid cloud particles (LREF) decreases with the increase of aerosol loading, while the effective radius of ice cloud particles (IREF) and cloud top height (CTH) increase during the cold season. Increased aerosol loading might inhibit the development of warm rain processes, transporting more cloud droplets above the freezing level and promoting ice cloud development. During the warm season, under low aerosol loading conditions, both the cloud microphysical (LREF and IREF) and macrophysical (cloud top height and cloud fraction) properties increase with the increase of aerosol loading, likely due to higher dust aerosol concentration in this region. In IGP, both LREF and IREF increase with the increase in aerosol loading during the cold season. In SCB, LREF increases with the increase in aerosol loading, while IREF decreases, possibly due to the higher hygroscopic aerosol concentration in the SCB during the cold season. Meteorological conditions also modulate the aerosol-cloud interaction. Under different convective available potential energy (CAPE) and relative humidity (RH) conditions, the influence of aerosol on clouds varies in the three regions. Under low CAPE and RH conditions, the relationship between LREF and aerosol in both the cold and warm seasons is opposite in the WTP: LREF decreases with the increase of aerosol in the cold season, while it increases in the warm season. This discrepancy may be attributed to a difference in the moisture condition between the cold and warm seasons in this region. In general, the influence of aerosols on cloud properties in TP and its adjacent regions is characterized by significant nonlinearity and spatial variability, which is likely related to the differences in aerosol types and meteorological conditions between different regions.

Drought Offsets the Controls on Colored Dissolved Organic Matter in Lakes

The concentration of colored dissolved organic matter (CDOM) in lakes is strongly influenced by climate, land cover, and topographic settings, but it is not known how drought may affect the relative importance of these controls. Here, we evaluate the controls of CDOM during two summers with strongly contrasting values of the Palmer drought index (PDI), indicating wet vs. dry conditions. We hypothesized that lake CDOM during a wet summer season is regulated mainly by the surrounding land cover to which the lakes are hydrologically connected, while, during drought, the lakes are disconnected from the catchment and CDOM is regulated by climatic and morphometric factors that govern the internal turnover of CDOM in the lakes. A suite of climate, land cover, and morphometric variables was assembled and used to explain remotely sensed CDOM values for 255 boreal lakes distributed across broad environmental and geographic gradients in Sweden and Norway. We found that PDI explained the variability in CDOM among lakes in a dry year, but not in a wet year, and that severe drought strongly decreased CDOM during the dry year. Large lakes, especially, with a presumed high degree of catchment uncoupling, showed low CDOM during the dry year. However, in disagreement with our hypothesis, climate, land cover, and morphometry all showed a stronger impact on lake CDOM in wet vs. dry years. Thus, drought systematically weakened the predictability of CDOM variations at the same time as CDOM was offset toward lower values. Our results show that drought not only has a direct effect on CDOM, but also acts indirectly by changing the spatial regulation of CDOM in boreal lakes.

Dirt Track Surface Preparation and Associated Differences in Speed, Stride Length, and Stride Frequency in Galloping Horses.

In racehorses, the risk of musculoskeletal injury is linked to a decrease in speed and stride length (SL) over consecutive races prior to injury. Surface characteristics influence stride parameters. We hypothesized that large changes in stride parameters are found during galloping in response to dirt racetrack preparation. Harrowing of the back stretch of a half-mile dirt racetrack was altered in three individual lanes with decreasing depth from the inside to the outside. Track underlay compaction and water content were changed between days. Twelve horses (six on day 2) were sequentially galloped at a target speed of 16 ms-1 across the three lanes. Speed, stride frequency (SF), and SL were quantified with a GPS/GNSS logger. Mixed linear models with speed as covariate analyzed SF and SL, with track hardness and moisture content as fixed factors (p < 0.05). At the average speed of 16.48 ms-1, hardness (both p < 0.001) and moisture content (both p < 0.001) had significant effects on SF and SL. The largest difference in SL of 0.186 m between hardness and moisture conditions exceeded the 0.10 m longitudinal decrease over consecutive race starts previously identified as injury predictor. This suggests that detailed measurements of track conditions might be useful for refining injury prediction models.

Variations in Aridity across the Asia-Australia Region during the Neogene and their Impact on Vegetation

Abstract Scientific drilling provides extended records of continental environmental conditions during the Neogene in Asia and northern Australia. Spectral data allows reconstruction of the environment using abundances of hematite and goethite. Hematite formation is favoured by dry or seasonal conditions. Hemipelagic sites show the most regular records. Monsoon strengthening started in the Early Miocene and peaked at 17–20 Ma in the Bay of Bengal and at 10–15 Ma in southern China before weakening after ∼12 Ma and ∼10 Ma respectively. The Indus dried after ∼8 Ma and again after 3 Ma, while eolian sediment sources to the Sea of Japan show increased aridity after 5 Ma and 3 Ma. The Mekong indicates increasing aridity after 6 Ma, similar to Eastern Australia. In contrast, NW Australia shows a trend towards wetter conditions after 8 Ma, a humid period at 4–6 Ma, followed by drying. There is a link between drying and vegetation in the Mekong and Pearl River basins, as well as Eastern Australia. Monsoon strengthening is linked to topographic uplift in the Himalaya, together with Tethyan gateway closure. Long term drying is likely driven by global cooling since the Middle Miocene.

Shifting groundwater fluxes in bedrock fractures: Evidence from stream water radon and water isotopes

Geologic features (e.g., fractures and alluvial fans) can play an important role in the locations and volumes of groundwater discharge and degree of groundwater-surface water (GW-SW) interactions. However, the role of these features in controlling GW-SW dynamics and streamflow generation processes are not well constrained. GW-SW interactions and streamflow generation processes are further complicated by variability in precipitation inputs from summer and fall monsoon rains, as well as declines in snowpack and changing melt dynamics driven by warming temperatures. Using high spatial and temporal resolution radon and water stable isotope sampling and a 1D groundwater flux model, we evaluated how groundwater contributions and GW-SW interactions varied along a stream reach impacted by fractures (fractured-zone) and downstream of the fractured hillslope (non-fractured zone) in Coal Creek, a Colorado River headwater stream affected by summer monsoons. During early summer, groundwater contributions from the fractured zone were high, but declined throughout the summer. Groundwater contributions from the non-fractured zone were constant throughout the summer and became proportionally more important later in the summer. We hypothesize that groundwater in the non-fractured zone is dominantly sourced from a high-storage alluvial fan at the base of a tributary that is connected to Coal Creek throughout the summer and provides consistent groundwater influx. Water isotope data revealed that Coal Creek responds quickly to incoming precipitation early in the summer, and summer precipitation becomes more important for streamflow generation later in the summer. We quantified the change in catchment dynamic storage and found it negatively related to stream water isotope values, and positively related to modeled groundwater discharge and the ratio of fractured zone to non-fractured zone groundwater. We interpret these relationships as declining hydrologic connectivity throughout the summer leading to late summer streamflow supported predominantly by shallow flow paths, with variable response to drying from geologic features based on their storage. As groundwater becomes more important for sustaining summer flows, quantifying local geologic controls on groundwater inputs and their response to variable moisture conditions may become critical for accurate predictions of streamflow.

Alternative Approaches for Rapid Evaluation of Frictional Resistance of Aggregates

Skid resistance of pavements plays a crucial role in ensuring the safety of road users, particularly under wet weather conditions. The standardized method for evaluating the skid resistance of aggregates, AASHTO PP103, requires using a three-wheel polishing device. That test procedure requires significant time for specimen preparation, testing, and monitoring of aggregate stockpiles. This study aims to propose alternative test methods to reduce the time required for the evaluation of skid resistance of aggregates. Two approaches were examined as alternatives to the AASHTO PP103 method. The first approach involved using a micro-deval abrasion device to polish the aggregates before evaluating the skid resistance of the aggregates using a dynamic friction tester. In the second approach, a multiple linear regression equation was proposed that uses conventional mechanical performance test results as independent variables to predict skid resistance. Twenty-one aggregate samples were collected from various sources in Texas for this study. The study results indicate that both approaches can be used as surrogate methods for AASHTO PP103 for rapid screening of the skid resistance of aggregates, which could help manage aggregate quality control and assurance.

X-ray computed tomography to observe the presence of water in macropores of cementitious materials

Corrosion of steel reinforcement in concrete is a common degradation mechanism occurring in infrastructures worldwide. Even though extensive research has been conducted over the last decades to accurately predict the influence of steel corrosion on concrete durability, a comprehensive understanding of several micro-scale processes simultaneously involved in the corrosion mechanism is still lacking. The application of X-ray Computed Tomography (X-ray CT) can contribute to elucidate these processes, since this technique allows observing the internal status of specimens non-destructively, over time, and with a spatial resolution in the range of µm. Nevertheless, the relatively low sensitivity of light elements (e.g., hydrogen and oxygen) to X-ray CT may hinder the observation of solution within the cementitious matrix. This consideration is discussed in this letter. The results of this study show that the detection of solution in macropores (e.g., air voids) through X-ray CT is not limited by the relatively low attenuation coefficient of the fluid per se, but more by the spatial resolution at which acquisitions are performed and by the dimensions of the porous volume where solution penetrates. The observations reported in this letter may open several opportunities to further study the influence of the moisture conditions of air voids on several degradation mechanisms of reinforced cementitious materials (e.g., steel corrosion, freeze-thaw damage), which have been rarely investigated with X-ray CT according to the literature. The application of these findings could significantly deepen the understanding of several micro- scale processes that affect the durability of reinforced cementitious materials which still need to be elucidated, as further discussed in the present letter.

Fire–climate–human dynamics over the last 1800 years in the mesic Araucaria‐Nothofagus forests

AbstractAimFew palaeoenvironmental studies have been performed in Araucaria‐Nothofagus forests, which are highly vulnerable to ongoing threats from climate change and anthropogenic activities. The primary goal of this work is to reconstruct past environmental changes related to fire disturbances over the last 1800 years in Tolhuaca National Park (TNP), Chile.LocationTNP, Araucanian region (38.2°S; 71.8°W), Northwestern Patagonia, Chile.TaxaAraucaria araucana (Araucariaceae), Nothofagus spp. (Nothofagaceae).MethodsWe completed charcoal and pollen analyses to create two new palaeoecological records that span 1800 years. We compared the lake‐based reconstruction with the available local tree‐ring fire scar chronologies from the last 430 years. Using these data, we compute forest index changes, biomass burning trends and compare with estimates of archaeological radiocarbon density. We place our inferences with context of published regional palaeoclimatic proxies from the Patagonian‐Andean region.ResultsOur results showed that fire activity was higher than present between 200 and 1500 CE, with peaks around 200–400 CE and 1100–1500 CE. Periods with high fire activity are associated with reduced forest cover, as Araucaria declined when mixed‐severity fire regime occurred for extended periods. Pollen assemblages suggested a shift from dry to wet climate conditions at 1500 CE, and from 1750 CE onward, the arrival of exotic species reflected the land‐use changes related to forest clearance and transhumance practices.Main ConclusionsThe palaeoenvironmental reconstructions showed changes in vegetation, fire and climate over the past 1800 years in TNP. Wildfires have been the main disturbance process modifying the vegetation structure in the Araucaria and Nothofagus forests. Since 1750 CE intensive post‐Hispanic land‐use changes (forest clearances by fire and logging) took place in the study area, reducing the native vegetation cover. Climate variability, modulated by SAM‐like and ENSO‐like conditions, influenced the fire activity (availability and flammability of fuels), concomitantly with high archaeological density. The recent (after 2000 CE) increase of catastrophic wildfires may negatively affect the conservation strategies of Araucaria‐Nothofagus forests.

Mechanical behavior of epoxy resin with graphite additive subjected to water absorption

Abstract Epoxy resin-based composites find extensive applications across various industries due to their unique mechanical properties. They are commonly used in gas and petrochemical industries for pipes and fittings in transmission lines. The primary objective of this study is to investigate changes in the mechanical properties of epoxy resin-based composites under different environmental moisture conditions. To achieve this, epoxy resin with varying weight percentages of graphite additive (0, 5, 10, 15, and 25 wt%) was used. The water absorption characteristics of the specimens were assessed by immersing samples in potable water (PW), distilled water (DW), a 10 vol% alkaline solution (NaCl), and a 10 vol% acidic solution (HCl), following ASTM standards. Both dry and wet samples were examined for various mechanical strengths. The results indicate that, for all weight percentages of graphite additive, water absorption follows the increasing order: NaCl &lt; PW &lt; DW &lt; HCl, as compared to the blank resin case. In terms of mechanical testing, increasing the weight percentage of graphite additive resulted in a 24 % decrease in Barcol hardness and a 39 % decrease in impact strength, while the hot deflection temperature (HDT) increased for 5 wt% and showed no significant effects for the other cases.

Interactive effects of soil moisture, air temperature and litter nutrient diversity on soil microbial communities and Folsomia candida population

Soil organisms play a key role in carbon and nutrient cycling in forest ecosystems. While soil organisms are strongly influenced by litter chemistry and are highly sensitive to abiotic conditions, little is known about the interactive effects of these two factors. To address this gap in knowledge, we conducted a 10 week microcosm experiment in which we simulated the effects of climate change on soil ecology. More specifically, we studied relationships among litter nutrient concentration, microbial biomass, Collembola demographic parameters, and litter decomposition, exploring the potential impacts of increasing air temperature and decreasing soil moisture. To develop a gradient of nutrient concentrations, we created six tree litter mixtures with materials gathered from Quercus pubescens and its companion species. In contrast to microbes, we observed that Collembola abundance and litter decomposition were interactively affected by soil moisture and air temperature: the negative effect of increasing air temperature on Collembola abundance was amplified by reduced soil moisture, whereas the positive effect of increasing air temperature on litter decomposition disappeared under reduced soil moisture conditions. In contrast to fungi, the response of bacterial biomass and Collembola abundance to litter nutrient concentration was dependent on abiotic conditions. More specifically, the relationships between nutrients, especially calcium and magnesium, and bacterial biomass and Collembola abundance were less robust or disappeared under drier or warmer conditions. In conclusion, our findings underscore that ongoing climate change could affect soil organisms directly as well as indirectly, by altering their responses to litter nutrient concentrations. In addition, we found that nutrient‐rich habitats might be more affected than nutrient‐poor habitats by altered climatic conditions.

Germination Requirement and Suitable Storage Method of Hydrocharis dubia Seeds.

Understanding of seed germination requirements and storage methods is very important to successfully conserve and restore aquatic vegetation. The main question addressed by the research was germination requirements and suitable seed storage methods of Hydrocharis dubia seeds. Furthermore, the water content and respiration rate of H. dubia seeds were studied under different storage conditions. The study found that light and high seed clustering density had a positive effect on germination, while burial had a negative effect. Germination percentages were 60.67 ± 6.11% and 28.40 ± 6.79% in light and dark conditions, respectively. Under clustering densities of 1 and 50, germination percentages were 6.00 ± 2.00% and 59.33 ± 0.67%, respectively. Germination percentages were 50.40 ± 5.00%, 3.20 ± 3.20%, and 0.80 ± 0.80% at depths of 0, 2, and 3 cm, respectively. Oxygen, water level, and substratum had no significant effect on seed germination. Storage method had a significant effect on seed germination, moisture content, and respiration rate. The germination percentages were 64.00 ± 1.67%, 85.20 ± 5.04%, and 92.80 ± 4.27% under the storage conditions of 4 °C-Dry, 4 °C-Wet, and Ambient water temperature-Wet for 2 years, respectively. The seeds had no germination under the storage conditions of Ambient air temperature-Wet and Ambient air temperature-Dry. Overall, the study indicates that seed germination of H. dubia is restricted by light, burial depth, and seed clustering density. Additionally, it was found that H. dubia seeds can be stored in wet environmental conditions at ambient water temperature, similar to seed banks. Specifically, the seeds can be stored in sand and submerged underwater at ambient water temperatures ranging from 4 °C to 25 °C. This study will help with the conservation and restoration of aquatic plants, such as H. dubia.

Impact of sand media continuous drying and rewetting cyclic on nutrients transformation performance from reclaimed wastewater effluent at soil aquifer treatment

Reusing reclaimed wastewater became a practical resource for water utilization in groundwater recharge and irrigation activities. However, the quality of reclaimed wastewater needs improvement to meet the environmental regulations and reduce contamination risks. A laboratory-scale study simulated a soil aquifer treatment (SAT) system, exploring the synergistic effects of wet and dry cycles alongside key physicochemical parameters on pollutant removal efficiency using a glass column filled with quartz sand as the filtration medium. The investigation focused on the cyclic wetting and drying phases to unravel their impact on removing NH4+, NO3−, and PO43−. The synthetic wastewater introduced into the system exhibited varying pollutant concentrations during wet and dry periods, influenced by dynamic soil water content (WC%), pH, dissolved oxygen (DO), and oxidation–reduction potential (ORP). The high removal rates of 93% for PO43− and 43% for Total N2 demonstrate the system’s capability to reduce concentrations significantly under dynamic alternating between wet and dry conditions. Results unveiled that the wet period consistently yielded higher removal rates for N2 species. Interestingly, for PO43−, the dry periods demonstrated a higher removal efficiency. Moreover, the study identified an average NO3− production during the experimental phases as a byproduct of nitrification. The average NO3− production in wet periods was 2.5 mg/L, whereas it slightly decreased to 2.2 mg/L in dry periods. These findings underscore the nuanced influence of wet and dry conditions on specific pollutants within SAT systems. Applying the logistic regression model and principal component analysis demonstrated the statistical significance of WC, pH, DO, and ORP in predicting wet/dry conditions, providing quantitative insights into their influential roles on the nutrient dynamic concentrations. This study contributes valuable data to our understanding of SAT systems, offering practical implications for designing and implementing sustainable wastewater treatment practices and pollution management across diverse environmental contexts.

Three-dimensional measurement method of binary particle collisions under dry and wet conditions

The description, calculation and design of solids processes, such as fluidization, pneumatic conveying or mixing, require knowledge of collision dynamics between particles and apparatus walls or interparticle collisions without, but often also with the presence of an additional liquid. For the study of such dry and wet interparticle collisions, an experimental setup is presented that allows the performance of dry or wet free binary collisions of spherical particles down to a minimum diameter of 1 mm. The recording of the particle motions in all three spatial directions is provided by two synchronized highspeed cameras. Methods and algorithms are presented for analyzing the translational and rotational motion in three-dimensional space, as well as for measuring the amount of liquid on the particles in the case of wet collisions. Motion data from dry collisions between equal sized and unequal sized spherical particles are compared with a three-parameter collision model. In addition, a first series of measurements of wetted collisions is used to compare the collision dynamics with dry collisions.

A Study of Structure–Property Correlation on Wet Spinning Conditions in Heat-Resistant Poly(m-phenylene isophthalamide) Hollow Fiber Membranes

A Study of Structure–Property Correlation on Wet Spinning Conditions in Heat-Resistant Poly(m-phenylene isophthalamide) Hollow Fiber Membranes

Intensive ammonium fertilizer addition activates iron and carbon conversion coupled cadmium redistribution in a paddy soil under gradient redox conditions

While over-fertilization and nitrogen deposition can lead to the enrichment of nitrogen in soil, its effects on heavy metal fractions under gradient moisture conditions remains unclear. Here, the effect of intensive ammonium (NH4+) addition on the conversion and interaction of cadmium (Cd), iron (Fe) and carbon (C) was studied. At relatively low (30–80 %) water hold capacity (WHC) NH4+ application increased the carbonate bound Cd fraction (F2Cd), while at relatively high (80–100 %) WHC NH4+ application increased the organic matter bound Cd fraction (F4Cd). Iron‑manganese oxide bound Cd fractions (F3Cd) and oxalate-Fe decreased, but DCB-Fe increased in NH4+ treatments, indicating that amorphous Fe was the main carrier of F3Cd. The variations in F1Cd and F4Cd observed under the 100–30-100 % WHC treatment were similar to those observed under low moisture conditions (30–60 % WHC). The C=O/C-H ratio of organic matter in soil decreased under the 30–60 % WHC treatment, but increased under the 80–100 % WHC treatment, which was the dominant factor influencing F4Cd changes. The conversion of NH4+ declined with increasing soil moisture content, and the impact on oxalate-Fe was greater at 30–60 % WHC than at 80–100 % WHC. Correspondingly, genetic analysis showed the effect of NH4+ on Fe and C metabolism at 30–60 % WHC was greater than at 80–100 % WHC. Specifically, NH4+ treatment enhanced the expression of genes encoding extracellular Fe complexation (siderophore) at 30–80 % WHC, while inhibiting genes encoding Fe transmembrane transport at 30–60 % WHC, indicating that siderophores simultaneously facilitated Cd detoxification and Fe complexation. Furthermore, biosynthesis of sesquiterpenoid, steroid, butirosin and neomycin was significantly correlated with F4Cd, while glycosaminoglycan degradation metabolism and assimilatory nitrate reduction was significantly correlated with F2Cd. Overall, this study gives a more comprehensive insight into the effect of NH4+ on activated Fe and C conversion on soil Cd redistribution under gradient moisture conditions.

Analysis of vibration response characteristics of composite pipeline based on finite element method

In order to ensure the good stability of the composite pipeline under fluid dynamic loads, finite element analysis method was applied to simulate and calculate the modal characteristics under dry and wet mode conditions. According to the working principle and structural characteristics of composite pipelines, the model was parameterized and simplified to improve computational efficiency and convergence. The modal testing platform is constructed, consisting of a combination of pipeline structure and pipeline support structure. The movement direction of the slider is limited by the guide rail used, allowing the horizontal section of the branch to move only along its own pipeline axis direction. The fluid structure coupling analysis technology was applied to obtain the vibration mode and spectral response results of the composite pipeline, which was verified through an experimental platform. The research results indicate that the natural frequency in wet mode was about 16 % lower than that in dry mode. In addition, it could be proven that the simulation scheme had good computational accuracy, with a maximum error of 9.2 %.

Tracing the biographies of textiles in the transition of medieval to modern times: Wool fabrics and brigandines from an Iberian castle

Findings of archaeological textiles and fibres in Northern Iberia are extremely rare. The occurrence of a set of textile fragments, dated between the 14th and 16th centuries CE at the Pambre castle (Palas de Rei, Lugo, Spain) is exceptional. The original stone roof of the southeastern tower was intact. The dark, cold and moist conditions inside the tower favoured the preservation of a unique series of waterlogged textile remains. In addition, a set of pseudomorphs preserved by mineral replacement were recovered from the east edge of the north wing in the main hall of the castle. Fibres have been identified using optical and scanning electron microscopy (SEM), and they have been chemically characterised using Energy Dispersive X-Ray Spectroscopy (EDX). We also performed analytical pyrolysis-GC-MS (Py-GC-MS) and thermally assisted hydrolysis and methylation (THM-GC-MS) of the wool fabrics and pseudomorphs to assess their state of degradation and the presence of chemical markers associated to the use of these textile remains. High performance liquid chromatography with diode array detection (HPLC-DAD-MS) and ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS/MS) analysis were applied on wool fabrics to identify the chemical markers of dyes but without success. To expand the information related to raw material identification and the technical aspects of the fabrics, further evidence such as adherences identified as opal phytoliths, seeds, and insect remains associated to wool fabrics were examined. These findings offer a unique glimpse into the clothing dated to the end of the Medieval period, and its life-cycle. Wool scraps were probably part of at least two different garments, whereas the mineralised textiles probably formed part of at least two brigandines which were made of bast fibres, flax, or hemp.

Wheel-rail contact wear analysis on curved lubricated track for heavy haul locomotive studies

The effect of lubrications on a curved track to heavy-haul wheel-rail contact wear is studied. To analyse wheel-rail contact wear damage due to existing high-adhesive AC locomotive, a methodology for investigation is proposed, and the locomotive models are required to run at 20 km/h under maximum traction efforts, and the simulations include a DC locomotive for comparison. An extended creep force model, which was developed by Polach and has been widely used for the wheel-rail contacts under dry and wet conditions with variable friction coefficients, is further extended to apply for the typical low-coefficient-friction modifier, oil, and grease lubricant conditions. The wear models from two pairs of wheel-rail materials are used to predict the wear rates, and the wear numbers Tγ are presented for discussions. The simulations show that the lubricants significantly reduce the wheel-rail contact wear.

Driving soil N2O emissions under nitrogen application by soil environmental factor changes in garlic-maize rotation systems

In multiple cropping systems, optimizing nitrogen (N) input can mitigate N2O emissions and sustain agricultural productivity in frequently disturbed environments. Nonetheless, there remains a notable gap in understanding the role of soil environment in the N application process. Hence, a three-annual field experiment spanning six growth seasons from 2019 to 2022 was conducted to assess the impacts of surface water filled-pore space (WFPS), NO3−−N, and meteorological factors under combined N applications during garlic (G: 300 and 240 kg N ha−1) and maize seasons (M: 220, 175, and 130 kg N ha−1) on soil N2O emissions and crop yields. The findings showed that reducing the annual N application rate by 45−150 kg ha−1 led to a significant decrease in N2O emission flux by 27.7%−69.4% and 30.7%−53.6% in maize and garlic season respectively, compared to conventional N application (G300M220). However, decreasing N application notably reduced garlic yield by 4.5–22.8%. Furthermore, reducing annual N application decreased net environmental and diminished net environmental and economic benefits (NEEB) by 3.7%−28.9%. Multiple regression analysis demonstrated that the residual NO3–−N in the soil before nitrogen application significantly influenced short-term N2O emissions post-application, while WFPS exerting a more pronounced effect during the maize season. Precipitation and temperature exhibited contrasting impacts on N2O emissions in the two crop seasons. Principal component analysis revealed that supplemental irrigation enhances crop yield in the maize growing season but also exacerbated N2O emissions due to the alternation of dry and wet conditions. Precipitation in the garlic growing season emerged as a crucial meteorological factor affecting crop yield and N2O emissions. The NEEB analysis suggested that reducing 45 kg N ha−1 in the maize season (G300M175) represents a more balanced N application approach to mitigate productivity and environmental risks in rotation systems. Therefore, accounting for the stimulating effect of soil environmental factors during the short-term N application process, adjusting irrigation practices based on seasonal precipitation and temperature variations can enhance productivity and reduce gaseous nitrogen losses in multiple cropping systems within semi-arid regions.