Carbon Water Research Articles

Tree-Ring δ13C and Intrinsic Water-Use Efficiency Reveal Physiological Responses to Climate Change in Semi-Arid Areas of North China

Climate change has had a widespread and profound impact on global temperature and precipitation patterns, especially in semi-arid areas. Plant δ13C and iWUE indicate the trade-off between carbon uptake and water loss, which is pivotal for understanding plant responses to climate change. Information about the long-term responses of the physiological and ecological processes of different tree species to climate change is also required. To investigate the impact of different forest stand structures and site conditions on long-term growth and physiological processes of coniferous and broad-leaved trees in the mountainous area of Beijing, we analyzed the tree-ring δ13C variation of four tree species (Platycladus orientalis, Pinus tabuliformis, Quercus variabilis, Robinia pseudoacacia) sampled from 64 plots with varying site and stand conditions. We found that the tree-ring δ13C of the four tree species varied from each other and was mainly affected by density and slope aspect, followed by slope and age. Both tree-ring δ13C and iWUE of the four tree species showed increasing trends over time, mechanistically linked to long-term changes in global CO2 concentration. This indicates the four native tree species have adapted well to climate change, and the risk of decline is relatively low. The increased iWUE translated into different growth patterns which varied with tree species, site, and stand condition. Different tree species have varying sensitivities to environmental factors. The iWUE of coniferous tree species is more sensitive to climate change than that of broad-leaved tree species, especially to temperature (T), the Standardized Precipitation Evapotranspiration Index (SPEI), and vapor pressure deficit (VPD).

Morphological characterization and transcriptome analysis of rolled and narrow leaf mutant in soybean

BackgroundIn plants, the leaf functions as a solar panel, where photosynthesis converts carbon dioxide and water into carbohydrates and oxygen. In soybean, leaf type traits, including leaf shape, leaf area, leaf width, and leaf width so on, are considered to be associated with yield. In this study, we performed morphological characterization, transcriptome analysis, and endogenous hormone analysis of a rolled and narrow leaf mutant line (rl) in soybean.ResultsCompared with wild type HX3, mutant line rl showed rolled and narrower leaflet, and smaller leaf, meanwhile rl also performed narrower pod and narrower seed. Anatomical analysis of leaflet demonstrated that cell area of upper epidermis was bigger than the cell area of lower epidermis in rl, which may lead rolled and narrow leaf. Transcriptome analysis revealed that several cytokinin oxidase/dehydrogenase (CKX) genes (Glyma.06G028900, Glyma.09G225400, Glyma.13G104700, Glyma.14G099000, and Glyma.17G054500) were up-regulation dramatically, which may cause lower cytokinin level in rl. Endogenous hormone analysis verified that cytokinin content of rl was lower. Hormone treatment results indicated that 6-BA rescued rolled leaf enough, rescued partly narrow leaf. And after 6-BA treatment, the cell area was similar between upper epidermis and lower epidermis in rl. Although IAA content and ABA content were reduced in rl, but exogenous IAA and ABA didn’t affect leaf type of HX3 and rl.ConclusionsOur results suggest abnormal cytokinin metabolism caused rolled and narrow leaf in rl, and provide valuable clues for further understanding the mechanisms underlying leaf development in soybean.

The impacts of structural parameters on performance and energy loss of the supersonic separator: A sensitivity analysis

The supersonic separator uses pressure energy to achieve highly efficient carbon capture and water vapor separation from the natural gas mixture. Structural parameters are crucial in determining both separation performance and pressure energy loss of the supersonic separator. However, a comprehensive understanding of how them influence flow behaviors and performance is hindered by their coupling effects and the limitations of numerical methods. This study introduces Euler-Lagrange-Euler model to predict separation performance and pressure energy loss of supersonic dehydration process with varying structural parameters. The results show that the expansion ratio of the divergent section, length of the convergent section, inlet radius of the inner body, and throat radius of the inner body significantly impact separation performance and pressure energy loss. Especially the first parameter, the swirl strength and centrifugal acceleration decay to 0.044 and 2.41 × 104 m s−2 as it increases. At the same time, the droplet removal rate significantly improves, but the separation performance does not increase indefinitely due to the shock waves. The dehydration efficiency first increases to 95.09 % at Er= 1.5 and then decreases; the dew point depression also expands to 25.28 K and then drops, and the corresponding pressure loss rises to 0.47 and then falls.

Biotechnological Innovations Unleashing the Potential of Olive Mill Wastewater in Added-Value Bioproducts.

Byproducts and wastes from the food processing industry represent an important group of wastes generated annually in large quantities. It is important to note that the amount of this waste will increase with industrialization, and effective solutions must be found urgently. Many wastes that cause environmental pollution are evaluated by their low-tech conversion into products with little economic value, such as animal feed and fertilizer. Therefore, the evaluation of food processing waste using effective recycling techniques has become an interesting subject with increasing population, ongoing biotechnological studies, and advances in technology. The conversion of food waste into biotechnological products via fermentation is a sustainable, environmentally friendly, and economical method in line with the principles of green chemistry. This approach promotes the reuse of food waste by supporting the principles of a circular economy and offers sustainable alternatives to fossil fuels and synthetic chemicals. This contributes to reducing the carbon footprint, preserving soil and water quality, and providing economic sustainability through the production of high-value products. In this study, the properties of olive mill wastewater, an important and valuable waste in the olive oil industry, its environmental aspects, and its use in biotechnological applications that integrate green chemistry are evaluated.

The effect of sparkling water on the systemic pharmacokinetics of paracetamol in older adults

Paracetamol absorption kinetics show considerable variability in older adults, complicating the development of effective dosing regimens in the advanced-age population. In previous research, sparkling water has been shown to influence absorption-related processes. This study aimed to apply these findings to older adults and investigate the impact of sparkling water on absorption-related variability and early exposure. To this end, fourteen volunteers, with a median age of 72.5, were enrolled in a small-scale, randomised, controlled clinical trial with a cross-over design. A single immediate-release 500 mg paracetamol tablet was administered with sparkling or still water. Venous blood samples were collected regularly over 8 hours and analysed using HPLC-UV. Reduced variability of absorption-related parameters and a trend towards higher early exposure were observed in the sparkling water group, as demonstrated by a 1.6-fold increased AUC0-30min, a 2-fold reduced geometric coefficient of variation (GCV) for AUC0-30min, and a reduced median [interquartile range] Tmax of 25.0 [20.0–30.0] min compared to 30.0 [25.0–45.0] min. Based on our findings, sparkling water as a real-life dosing condition might improve paracetamol absorption kinetics and early exposure in the advanced-age population.

Relationship between Ecosystem-Services Trade-Offs and Supply–Demand Balance along a Precipitation Gradient: A Case Study in the Central Loess Plateau of China

Although the theory of ecosystem services (ESs) is important for guiding land-use planning, knowledge of ESs trade-offs and supply–demand mechanisms is still lacking, and the characteristics of the correlation between the size of trade-offs and the balance between supply and demand along the precipitation gradient have not yet been clarified. In order to supplement this area of knowledge of ESs, we selected 30 small watersheds in high-, medium- and low-precipitation areas as study units. A biophysical model and socio-economic data were used to calculate supply and demand for carbon sequestration, soil conservation and water yield. Redundancy analysis and regression analysis were used to study the ESs trade-offs, the supply–demand dynamics, and the characteristics of their correlation. The results were as follows. (1) The supply and balance between supply and demand of the three ESs, the trade-off between carbon sequestration and water yield and the trade-off between soil conservation and water yield trended downwards from the high-precipitation area to the medium-precipitation area to the low-precipitation area. (2) The primary factors influencing balance between supply and demand with regard to carbon sequestration in high-, medium- and low-precipitation areas were population density and soil organic-matter content, and the size of the conditional effects were greater than 53%. The dominant factor affecting the balance between supply and demand with regard to soil conservation in the three precipitation areas was slope gradient, and the conditional effect was greater than 40%. The most significant determinants of balance between supply and demand with regard to water yield in the three precipitation areas were grassland area, forest area and precipitation, and the conditional effects were greater than 22%. (3) The most significant determinants of the trade-off between carbon sequestration and water yield in high-, medium- and low-precipitation areas were forest, soil organic-matter content and population density, and the conditional effects were all greater than 45%; the primary factors affecting the trade-off between soil conservation and water yield in high-, medium- and low-precipitation areas were grassland and slope gradient, and the conditional effects were all greater than 24%. (4) The relationship between the balance between supply and demand and trade-off size often followed a quadratic function; the next-most-common relationship was a monotonous nonlinear response, and a linear response relationship was relatively rare. This study revealed the factors influencing balance between supply and demand and trade-offs with regard to ESs and the characteristics of their correlations in areas with different degrees of precipitation, which provided a new idea for the synchronous regulation of ESs in the context of conflicts and supply–demand imbalance.

Environmental Importance of Mulberry: A Review

Mulberry is a woody, deciduous tree that is economically important. It is regarded as a distinctive plant on the planet due to its widespread geological distribution across continents, ability to be cultivated in various forms, multiple uses of leaf foliage and positive impact in environmental safety approaches such as ecorestoration of degraded lands, bioremediation of polluted sites, water conservation, soil erosion prevention, and enhancement of air quality through carbon sequestration. Mulberry has a robust root system. Mulberry root systems can significantly improve soil shear strength and anti-erosive capacity. Mulberry plantations are extremely effective in suppressing sand storms and conserving water and soil. The review investigates the role of mulberry trees in carbon sequestration, ecorestoration, soil and water conservation, bioremediation of heavy metals and afforestation.

Seasonal precipitation distribution determines ecosystem CO2 and H2O exchange by regulating spring soil water–salt dynamics in a brackish wetland

Abstract The intensification of the global hydrological cycle is anticipated to increase the variability of precipitation patterns. Brackish wetlands respond to changes in precipitation patterns by regulating the absorption and release of CO2 and H2O to maintain the stability of ecosystem functions. However, there is limited understanding of how the inter‐seasonal precipitation distribution (SPD) affects ecosystem CO2 and H2O exchange compared with annual precipitation totals. Here, we conducted four consecutive years of field experiments in a brackish wetland, manipulating the proportion of precipitation across different seasons while maintaining a constant annual precipitation total. We utilized five inter‐SPD proportions (+73%, +56%, control (CK), −56%, −73%) to examine the effects of SPD on ecosystem CO2 and H2O exchange. Our findings revealed that the annual ecosystem CO2 and H2O fluxes showed a trend of decreasing with the decrease in spring precipitation distribution. Among them, the annual net ecosystem CO2 exchange, evapotranspiration, carbon use efficiency and water use efficiency were shown to be more sensitive to decrease in spring precipitation distribution and increase in summer and autumn precipitation distribution. This negative asymmetric response pattern suggests that annual ecosystem CO2 and H2O exchange is primarily governed by seasonal precipitation variability, with spring soil water–salt dynamics identified as the key driver. Therefore, this association can be explained by the fact that drought of the early growth stage exacerbates soil salinization and inhibits vegetation colonization and growth, thereby greatly impairing the annual CO2–H2O exchange capacity of brackish wetlands. Our results emphasized that the spring extreme precipitation‐induced soil water–salt conditions will greatly influence CO2 and H2O exchange in brackish wetlands in the future. These findings are crucial for improving predictions of the carbon sequestration and water‐holding capacity of brackish wetlands. Read the free Plain Language Summary for this article on the Journal blog.

Dynamic Replacement of Soil Inorganic Carbon under Water Erosion

The dynamic replacement of soil organic carbon represents a pivotal mechanism through which water erosion modulates soil–atmosphere CO2 fluxes. However, the extent of this dynamic replacement of soil inorganic carbon within this process remains unclear. In our study, we focused on Yuanmou County, China, a prototypical region afflicted by water erosion, as our study area. We leveraged the WaTEM/SEDEM model to quantify the dynamic replacement of soil carbon, accounted for the average annual net change in soil carbon pools, and used isotope tracer techniques to track and measure the process of the coupled carbon–water cycling. This comprehensive approach enabled us to scrutinize the dynamic replacement of soil carbon under water erosion and delineate its ramifications for the carbon cycle. Our findings unveiled that the surface soil carbon reservoir in the Yuanmou area receives an annual replacement of 47,600 ± 12,600 tons following water erosion events. A substantial portion, amounting to 39,700 ± 10,500 tons, stems from the dynamic replacement of soil inorganic carbon facilitated by atmospheric carbon. These results underscore the critical role of the dynamic replacement of soil inorganic carbon in altering the soil–atmosphere CO2 fluxes under water erosion, thereby influencing the carbon cycle dynamics. Consequently, we advocate for the integration of water erosion processes into regional carbon sink assessments to attain a more comprehensive understanding of regional carbon dynamics.

Mechanistic insights into phosphoactivation of SLAC1 in guard cell signaling

Stomata in leaves regulate gas (carbon dioxide and water vapor) exchange and water transpiration between plants and the atmosphere. SLow Anion Channel 1 (SLAC1) mediates anion efflux from guard cells and plays a crucial role in controlling stomatal aperture. It serves as a central hub for multiple signaling pathways in response to environmental stimuli, with its activity regulated through phosphorylation via various plant protein kinases. However, the molecular mechanism underlying SLAC1 phosphoactivation has remained elusive. Through a combination of protein sequence analyses, AlphaFold-based modeling and electrophysiological studies, we unveiled that the highly conserved motifs on the N- and C-terminal segments of SLAC1 form a cytosolic regulatory domain (CRD) that interacts with the transmembrane domain(TMD), thereby maintaining the channel in an autoinhibited state. Mutations in these conserved motifs destabilize the CRD, releasing autoinhibition in SLAC1 and enabling its transition into an activated state. Our further studies demonstrated that SLAC1 activation undergoes an autoinhibition-release process and subsequent structural changes in the pore helices. These findings provide mechanistic insights into the activation mechanism of SLAC1 and shed light on understanding how SLAC1 controls stomatal closure in response to environmental stimuli.

Effective degradation of various bacterial toxins using ozone ultrafine bubble water.

Infectious and foodborne diseases pose significant global threats, with devastating consequences in low- and middle-income countries. Ozone, derived from atmospheric oxygen, exerts antimicrobial effects against various microorganisms, and degrades fungal toxins, which were initially recognized in the healthcare and food industries. However, highly concentrated ozone gas can be detrimental to human health. In addition, ozonated water is unstable and has a short half-life. Therefore, ultrafine-bubble technology is expected to overcome these issues. Ultrafine bubbles, which are nanoscale entitles that exist in water for considerable durations, have previously demonstrated bactericidal effects against various bacterial species, including antibiotic-resistant strains. This present study investigated the effects of ozone ultrafine bubble water (OUFBW) on various bacterial toxins. This study revealed that OUFBW treatment abolished the toxicity of pneumolysin, a pneumococcal pore-forming toxin, and leukotoxin, a toxin that causes leukocyte injury. Silver staining confirmed the degradation of pneumolysin, leukotoxin, and staphylococcal enterotoxin A, which are potent gastrointestinal toxins, following OUFB treatment. In addition, OUFBW treatment significantly inhibited NF-κB activation by Pam3CSK4, a synthetic triacylated lipopeptide that activates Toll-like receptor 2. Additionally, OUFBW exerted bactericidal activity against Staphylococcus aureus, including an antibiotic-resistant strain, without displaying significant toxicity toward human neutrophils or erythrocytes. These results suggest that OUFBW not only sterilizes bacteria but also degrades bacterial toxins.

Effect of calcium sources on enzyme-induced carbonate precipitation to solidify desert aeolian sand

Enzyme-induced carbonate precipitation (EICP) is a promising technique for soil reinforcement. To select a suitable calcium source and a suitable solution amount for aeolian sand stabilization using EICP, specimens treated with different solution amounts (1.5, 2, 2.5, 3, and 3.5 L/m2). Surface strength, crust thickness, calcium carbonate content (CCC) and water vapor adsorption tests were performed to evaluate the effect of two calcium sources (calcium acetate and calcium chloride) on aeolian sand solidification. The plant suitability of solidified sand was investigated by the sea buckthorn growth test. The suitable calcium source was then used for the laboratory wind tunnel test and the field test to examine the erosion resistance of solidified sand. The results demonstrated that Ca(CH3COO)2-treated specimens exhibited higher strength than CaCl2-treated specimens at the same EICP solution amount, and the water vapor equilibrium adsorption mass of Ca(CH3COO)2-treated specimens was less, indicating that Ca(CH3COO)2-solidified sand was more effective and had better long-term stability. In addition, plants grown in Ca(CH3COO)2-treated sand had greater seedling emergence percentage and higher average height, which indicated that calcium acetate is a more suitable calcium source for EICP treatment. Furthermore, the surface strength and crust thickness of solidified sand increased with increasing the solution amount. For sand treated with 3 L/m2 of solution, the excessive strength and thickness of the crust made plants growth difficult, and the performance of sand treated with more than 2 L/m2 of solution significantly improved. Thus, the solution amount of 2–3 L/m2 is suggested for engineering applications. The sand solidified using EICP in the field could effectively mitigate wind erosion and facilitate the growth of native plants. Therefore, EICP can be combined with vegetative method to achieve long-term wind erosion control in the future.

Greenhouse gas emissions and carbon and water footprints during processing of Lei bamboo shoots

Lei bamboo shoots are extensively used in the food processing industry, producing solid waste such as bamboo shoot shells and liquid wastewater. This study analyzed several sewage indicators, revealing that the majority exceed the national standards of China for direct water discharge. A field experiment was conducted over a period of 4 months to evaluate the effects of different treatments during the natural decomposition of bamboo shoot shells.The treatment groups consisted of the boiled experimental group (EG) and the control group (CG). Results showed that in EG, the methane emission increased by 8.6% (P < 0.05), the carbon dioxide emission increased significantly by 19.7% (P < 0.01), and the nitrous oxide emission decreased by 37.9% (P < 0.01) relative to those in CG. Regression analysis was employed to establish a relationship model between CH4, CO2, and N2O emission fluxes and temperature and humidity in the EG and CG groups. A specific functional relationship was identified between CH4 and CO2 emission fluxes and temperature and humidity, but N2O emission was present. No significant correlation was found between flux and ambient temperature and humidity (R2 < 0.3). We also estimated that the carbon dioxide emissions and water consumption of producing 1 kg of canned bamboo shoots were 2.8669 kg and 86.8 L, covering the processes in the life cycle of bamboo shoot products. This study identifies the potential water pollution problems and provides insights into resource utilization and recycling in bamboo shoot food processing, facilitating the realization of clean production processes. It also sheds light on the water footprint of bamboo shoot products throughout their life cycle, and the carbon footprint research provides valuable references.

The promotion of sustainable land use planning for the enhancement of ecosystem service capacity: Based on the FLUS-INVEST-RUSLE-CASA model.

Land Use/Land Cover (LULC) is one of the most significant human variables influencing the efficiency of Ecosystem Services (ESs) in terrestrial ecosystems. Theoretical and technical assistance for regional sustainable land use planning and management, as well as ecosystem conservation and restoration, is provided by investigating the influence of changes in the LULC pattern on the efficiency of ESs. This research focuses on the interactions between socioeconomic activities and natural ecological processes in the Three Gorges Reservoir Area (TGRA). We use LULC data from the TGRA for the years 1990, 2000, 2010, and 2020. The study includes the analysis and calculation of the spatiotemporal evolution features of the current LULC pattern and the efficiency of ESs, including their spatiotemporal distribution. Considering the TGRA's national development orientation and guidance, three potential LULC patterns are constructed under various develop-ment scenarios. To calculate the efficiency of ESs, the GeoSOS-FLUS future LULC simulation model is linked, and several methodologies such as INVEST, RUSLE, and CASA are used. The goal is to investigate the influence of future changes in LULC patterns on ESs efficiency. The findings show the following: (1) From 1990 to 2020, the values of water conservation services in the TGRA decreased and subsequently increased. High-value areas are primarily located in the reservoir's centre and eastern sections, whereas low-value areas are mostly found in the western section. Soil conservation service values initially declined and later climbed. The TGRA's carbon storage services have in-creased yearly, from 552.64 g/m2 in 2000 to 615.92 g/m2 in 2020. (2) In the ecological protection scenario, carbon storage and soil erosion increased compared to the ecosystem services in 2020. The ecological system service benefits are greater when compared to the natural development scenario. (3) The four ESs show positive spatial correlations across all three scenarios, and local spatial au-tocorrelation analysis findings demonstrate that carbon storage, water yield, and habitat quality have comparable spatial distributions across all three scenarios. To some extent, high-value areas for water conservation, soil retention, carbon storage, and habitat quality overlap.

Ecosystem Services Assessment and Multi-Scenario Prediction in Liaoning Province from 2000 to 2020

Ecosystem service assessment and prediction play a crucial role in sustainable regional development and resource management. Liaoning Province, as a typical representative of Northeast China, faces rapid development challenges such as urbanization, industrialization, and agricultural modernization. At the same time, there is an urgent need for a deeper understanding of the evolution trends of its ecosystems and their impact on ecosystem services. This study employed the InVEST-Markov-PLUS model to conduct simulated research on the assessment of past and future ecosystem services and multi-scenario predictions in Liaoning Province. Based on the land-use changes in Liaoning Province from 2000 to 2020, the InVEST model was used to evaluate the spatiotemporal variations in carbon storage, soil conservation, and water yield in the ecosystem services from 2000 to 2020. Additionally, the equivalent factor method was employed to calculate the value of ecosystem services in Liaoning Province during the same period. Furthermore, by integrating the PLUS and Markov models with the actual conditions of Liaoning Province, four land-use development scenarios for 2030 were constructed, including natural development, economic priority, ecological protection, and cropland protection. The land-use distribution and the quantities and values of ecosystem services under these scenarios were simulated. The study revealed the following findings： ① From 2000 to 2020, carbon storage and soil retention in Liaoning Province showed an overall increasing trend, whereas water yield exhibited a fluctuating decrease trend initially, followed by an increase and then another decrease. ② Carbon storage and soil retention in Liaoning Province showed higher values in the eastern mountainous areas and western hilly regions, with lower values in the central region. Water yield showed a decreasing trend from east to west. ③ The value of ecosystem services increased from 547.94 billion yuan to 565.53 billion yuan, with a total increase of 17.58 billion yuan during the study period. All four types of services showed an increase, with cultural services experiencing the fastest change. ④ In 2030, carbon storage and soil retention in Liaoning Province decreased in all scenarios except for in the ecological protection scenario. Water yield increased only in the cropland protection scenario, whereas it decreased in the other three scenarios. The value of ecosystem services in the study area increased in all scenarios except for in the economic priority scenario.

Gas and water migration in cement slurries at different curing times

Gas and water migration in the hydrating cement slurry is a major cause of well completion failure. Gas and water migration may occur at different curing times due to varying well conditions and cement slurries. The current study has not been carried out to investigate the gas and water migration at different curing times. In this paper, theoretical calculations and migration experiments are used to investigate the gas and water migration in cement slurry at different curing times. The gas and water migration process can be divided into the formation rock to annular cement slurry (F-A) stage and the bottom to top (B-T) stage. At relatively short curing time, the cement slurry is more like a viscous fluid and there is clear interface between the gas and slurry. The pressure difference required for gas migration in F-A stage is very small. Maximum velocity of gas bubble migration in B-T stage is closely related to gas bubble size and cement viscosity. The smaller the size of gas bubble and the greater the viscosity of the cement slurry, the smaller the maximum velocity of the gas bubble will be. There is no clear interface between the water and slurry at relatively short curing time. The pressure difference of water migration is small. At relatively long curing time, the cement slurry has a certain of gel strength and there is also clear interface between the gas/water and slurry. The water migration is similar to gas migration. The pressure difference required for gas and water migration in F-A stage increases as the static gel strength increases. The size of the gas and water bubbles formed after invasion increases as the static gel strength increases. The critical radius at which gas and water bubbles can move is closely related to the static gel strength of the cement slurry. The greater the static gel strength, the larger the critical radius will be. The channeling path sizes of the gas and water migration are all small at relatively short curing times. The dimensions of the channel are gradually increasing from bottom to top. The pressure difference of gas migration and the dimension of channel increase as curing time increases. When the cement slurry cures for a long enough period, the gas cannot migrate in the cement slurry, but only along the weak cement slurry-wellbore interface.

Design-Optimization of Conventional Steel Structures for Realization of the Sustainable Development Objectives Using Metaheuristic Algorithm

The construction industry presents a significant environmental challenge due to its substantial environmental footprint, utilization of limited natural resources, and contribution to pollution and climate change. Additionally, optimizing the weight, cost, and duration of construction is crucial for enhancing serviceability, flexibility, efficiency, and profitability. In this research, the relationship between structure weight and other objective functions was explored using the single-objective gray wolf algorithm to investigate their impact on carbon footprint, water footprint, and construction time. Furthermore, employing a multi-objective optimization algorithm, a building structure was optimized for three systems featuring different structural frames based on the specified objective functions. The results revealed that the structure with intermediate steel moment-resisting frames exhibited the shortest construction time but incurred the highest construction cost. Conversely, the structure with intermediate steel moment-resisting frames with special steel concentric bracing demonstrated the lowest carbon footprint and water footprint among the studied structural frames. Consequently, the structure with intermediate steel moment-resisting frames with special concentric steel bracing was proposed as a green structure, emphasizing its environmentally friendly characteristics.

Energy Consumption and Saved Emissions of a Hydrogen Power System for Ultralight Aviation: A Case Study

The growing concern about climate change and the contemporary increase in mobility requirements call for faster, cheaper, safer, and cleaner means of transportation. The retrofitting of fossil-fueled piston engine ultralight aerial vehicles to hydrogen power systems is an option recently proposed in this direction. The goal of this investigation is a comparative analysis of the environmental impact of conventional and hydrogen-based propulsive systems. As a case study, a hybrid electric configuration consisting of a fuel cell with a nominal power of about 30 kW, a 6 kWh LFP battery, and a pressurized hydrogen vessel is proposed to replace a piston prop configuration for an ultralight aerial vehicle. Both power systems are modeled with a backward approach that allows the efficiency of the main components to be evaluated based on the load and altitude at every moment of the flight with a time step of 1 s. A typical 90 min flight mission is considered for the comparative analysis, which is performed in terms of direct and indirect emissions of carbon dioxide, water, and pollutant substances. For the hydrogen-based configuration, two possible strategies are adopted for the use of the battery: charge sustaining and charge depleting. Moreover, the effect of the altitude on the parasitic power of the fuel cell compressor and, consequently, on the net efficiency of the fuel cell system is taken into account. The results showed that even if the use of hydrogen confines the direct environmental impact to the emission of water (in a similar quantity to the fossil fuel case), the indirect emissions associated with the production, transportation, and delivery of hydrogen and electricity compromise the desired achievement of pollutant-free propulsion in terms of equivalent emissions of CO2 and VOCs if hydrogen is obtained from natural gas reforming. However, in the case of green hydrogen from electrolysis with wind energy, the total (direct and indirect) emissions of CO2 can be reduced up to 1/5 of the fossil fuel case. The proposed configuration has the additional advantage of eliminating the problem of lead, which is used as an additive in the AVGAS 100LL.

Carbon and water vapor exchanges coupling for different irrigated and rainfed conditions on Andean potato agroecosystems

The fundamental exchange of water for carbon lays the groundwork for understanding the interplay between carbon and water cycles in terrestrial ecosystems, providing valuable insights into global water and carbon balances and vegetation growth. Inherent water use efficiency (IWUE) was used as a study framework of the diurnal patterns and degree of coupling of carbon and water exchange to investigate the net ecosystem carbon exchange (NEE) responses of three water regime potato cropping systems [full-irrigation (FI), deficit-irrigation (DI), and rainfed (RF)] in Cundinamarca, Colombia. The eddy covariance method was used to determine CO2 and water fluxes, surface resistances, and the omega decoupling factor (Ω). Additionally, leaf area index (LAI), and specific leaf area (SLA) were assessed to determine the canopy influence on carbon and water exchange. The highest carbon sink activity (NEE = -311.96 ± 12.82 g C m−2) at FI, is primarily attributed to a larger canopy with high autotrophic activity and low internal resistance. This supported a highly coupled and synchronized exchange between evapotranspiration (ET) and gross primary production (GPP), as reflected in the highest IWUE (4.7 mg C kPa s−1 kg−1 H2O). In contrast, the lower sink capacity at DI (NEE = − 17.3 ± 4.6 g C m−2) and the net carbon source activity from RF (NEE = 187.21 ± 3.84 g C m−2) were related to a smaller leaf area available for water and carbon exchange, resulting in lower IWUE (2.3 and 1.01 mg C kPa s−1 kg−1 H2O, respectively) and a decoupled and desynchronized gas exchange caused by unbalanced restrictions on ET and GPP fluxes. These results provide new information on carbon–water interactions in potatoes and improve the understanding of carbon sequestration and drought effects on potato sink activity.

On the diffusive model of C&lt;sub&gt;60&lt;/sub&gt; fullerene clusterization in liquids

Purpose of research. The purpose of the study is to explain the mechanisms of clustering of fullerene molecules in liquid media observed using various structural nuclear -physical methods, as well as the interpretation of experimental data within the framework of a microscopic diffusion model. Methods. The article gives a brief overview of the results of positron annihilation spectroscopy, small-angle neutron scattering, translucent electron microscopy, with which the geometric parameters of fullerene clusters in solutions were established. The theoretical method of research is the microscopic diffusion model “Limited diffusion aggregation”, which describes the kinetic processes of clusterization. Results. The diffusion limited aggregation model displays adequately the mechanism of formation of C60 molecules in the form of fractal units in the volume of fluid, observed in experiments on positron annihilation spectroscopy and small-angle neutron scattering. The structural indicators of aggregate fullerene particles in carbon disulfide, o-Xylene, toluene, water and other solvents are analyzed. The properties of various diffusion models (the reaction limited aggregation model and the diffusion limited aggregation model) are considered and their combination in relation to the assessmentsof the kinetics of fullerene aggregation in solutions. A quantitative comparison of the results of the discussed models was carried out using the example of carbon disulfide. Conclusion. The diffusion microscopic models adequately describe the phenomenon of fullerene aggregation in polar and non-polar solvents, which are recorded by various nuclear methods (positron annihilating spectroscopy and small-angle neutron scattering), the most reliable is the diffusion limited aggregation model, more than that, it is the basis of a numerical definition of structural structures parameters of units. Compared to neutron scattering, with the annihilation of positrons, in the aggregation of fullerene the [Ps–C60] molecular complexes participate in the clusterization, but this does not affect the change in the size of the cluster and the reliability of the results.