Environmental Conditions Research Articles

Hierarchical Bayesian quantification of aerodynamic effects on an offshore wind turbine under varying environmental and operational conditions

This paper proposes a hierarchical Bayesian model updating approach to quantify variability of aerodynamic stiffness and damping of an offshore wind turbine (OWT) under different environmental and operational conditions (EOCs) using in-situ vibration data and SCADA (supervisory control and data acquisition) over two months of continuous monitoring. The considered OWT is a Haliade 150, 6 MW GE turbine on a jacket substructure located at the Block Island Wind Farm in Rhode Island, USA. The OWT has been instrumented with a continuous monitoring system including an array of accelerometers and strain gauges. The modal parameters of the OWT are extracted using an automated system identification approach. These parameters exhibit significant variations under varying EOCs. This variation is more significant in natural frequencies and damping ratios of the first fore-aft bending mode due to the aerodynamic effects. In this paper, a modeling approach is proposed by introducing a spring and a damper at the nacelle level in the fore-aft direction to account for the observed aerodynamic effects. A hierarchical Bayesian model updating is formulated and implemented to update parameters representing the effects of aerodynamic stiffness and damping, as well as their statistical properties such as mean and covariance matrix which are updated as hyperparameters. To account for the correlation between aerodynamic effects and EOCs, the updating parameters are assumed to be functions of EOCs such as rpm and wind speed. Two levels of hierarchical Bayesian model updating are performed and compared. In level 1, only modal parameters are used in model updating, while in level 2, the assumed correlation between EOCs and modal parameters are accounted for to reduce the uncertainty of aerodynamic effects in the model. In addition to hyperparameters, the proposed hierarchical Bayesian approach provides statistical properties of error function by collecting the residual uncertainties that have not been accounted for, e.g., modeling errors, measurement noise and random disturbances. The predicted modal parameters using two levels of hierarchical Bayesian approach are compared with their identified counterparts, and the results indicate that level 2 approach significantly reduces estimation uncertainty in aerodynamic effects and produces model predictions consistent with observed values of natural frequencies and damping ratios.

A review: Breeding behavior and management strategies for improving reproductive efficiency in bulls.

This review focuses on bull breeding behaviors and management strategies to improve reproductive efficiency. Breeding soundness evaluations are utilized to classify a bull's physical ability and sperm quality, yet roughly 20 % of bulls fail to meet the minimum criteria. Furthermore, despite achieving the minimum criteria, few bulls in multi-sire breeding groups sire the majority of calves, indicating a need for better understanding of bull behavior that impact siring capacity, and thus, a bull's reproductive efficiency. Several factors influence bull libido such as age, breed, and environmental conditions. Although service capacity tests have been used to measure libido, standardization and repeatability, along with variability in age and breed, can be problematic. Management in collection facilities largely focuses on the pre-stimulation of bulls through behavioral cues for better sperm quality and quantity during collection, thus improving a bull's reproductive efficiency through fewer collections with increased breeding doses harvested. In management of multi-sire breeding groups, understanding social interactions, bull-to-female ratios, synchronization of females, and DNA testing to determine parentage, are techniques that can be utilized to improve reproductive efficiency. New research utilizing remote monitoring technology is being developed to better understand bull behavior without the constraints of direct observation. This technology may be used to predict siring capacity, better manage bulls based on social dynamics, and potentially detect lameness or injury in bulls that may impact siring capacity. A better understanding of developing management strategies of breeding behaviors should be further investigated to improve reproductive success of bulls.

The Plant Ionome as a Functional Trait: Variation across Bioclimatic Regions and Functional Groups.

Plant chemical composition is a trait gaining increasing importance in plant ecology. However, there is limited research on the patterns and drivers of its variation among different plant functional groups and bioclimatic regions. We conducted an analysis of ionomes utilising X-ray fluorescence on 83 plant species from four distinct functional groups (grasses, legumes, forbs and woody species); we marked plots across 15 sites located in both the desert and Mediterranean bioclimatic regions. The primary factors influencing variations in ionomes are predominantly attributed to bioclimatic factors rather than soil composition. Across all functional groups, plants from the Mediterranean region are characterised by greater association with calcium, whereas desert plants exhibit a higher affinity for strontium (Sr), suggesting its potential role in drought tolerance. Among functional groups, grasses uniquely exhibit distinct ionomic features, primarily due to their higher silicon (Si) concentrations. Plant species' affinities for certain elements and their interactions are likely driven by physiological constraints, whereas variations within a functional group are mostly driven by environmental conditions. We conclude that interactions among elements form physiological phenotypes shaped by natural selection under large-scale environmental variability, making plant ionome composition an important plant functional trait.

Study of the nitrogen fluorescence yield under different environmental conditions in alpha radioactivity telemetry technique

Study of the nitrogen fluorescence yield under different environmental conditions in alpha radioactivity telemetry technique

Assessment of macrobenthos in evaluating the restoration effects of artificial mangrove planting on tidal flats in Zhejiang, China.

Artificially planted mangroves are widely used for tidal flat restoration, but their effectiveness in restoring these ecosystems remains unclear. Macrobenthos, as key indicators of tidal flat ecosystem health, can reflect changes in environmental conditions and quality resulting from the introduction of artificial mangroves. This study aimed to investigate the ecological restoration effects of artificially planted mangroves in northern China by surveying macrobenthic communities across four regions in June 2023. We compared the macrobenthic community structures in mangrove zones with those in Spartina alterniflora or unvegetated mudflat control zones by estimating habitat quality indices and community structure analyses. Additionally, we explored the relationship between community structures and environmental factors to identify key drivers of community structure changes. Significant differences in species abundance and biomass were observed across the four regions, with mudflat zones exhibiting the highest values, followed by mangrove and Spartina alterniflora zones. Beta diversity was higher in mangrove zones compared to control zones, driven primarily by turnover components. The AMBI index indicated excellent ecological conditions in 18-year-old mangrove zone on Maoyan Island, while poorer conditions were observed in the mangrove zone of Zhoushan City. Environmental factors, such as sand content, organic carbon content, and elevation, significantly influenced macrobenthic community distribution. Overall, our findings suggest that the 18-year-old mangrove zone on Maoyan Island is ecologically stable and demonstrates significant restoration effects. Using macrobenthos to assess the restoration efficacy of mangroves proves to be both effective and feasible. Furthermore, while the mangroves have successfully established and grown, their long-term survival depends on the active involvement of local stakeholders, highlighting the importance of long-term monitoring and adaptive management strategies.

Dielectric breakdown characteristics of flux-contaminated printed circuit boards in different environmental conditions

Dielectric breakdown characteristics of flux-contaminated printed circuit boards in different environmental conditions

Soil macrofauna communities vary by land use type and environmental conditions in the Serengeti-Mara ecosystem

Soil macrofauna communities vary by land use type and environmental conditions in the Serengeti-Mara ecosystem

Dynamics of major and trace elements during leaf litter decomposition in semi-arid mangrove subject to urban runoff.

This study examined the dynamics of major elements and trace metals (TM) during litterfall decomposition in two mangrove forests-control and urban-along New Caledonia's coast. A litterbag experiment was carried out for 72days for the two main species (Rhizophora stylosa, and Avicennia marina) of the island. Results showed that the urban runoff enhances the leaching of some major elements (K, Mg, Na) during litter decomposition. The enrichment of TM in litter is also faster at the urban site. The dynamics of some major elements and TM are rather influenced by species metabolisms or element's characteristics such as Mn which does not increase in concentration in the decomposing litter. This study concludes that urban runoff accelerates the leaching of major elements and the enrichment of TM during leaf litter decomposition in mangrove forests, with species-specific factors and environmental conditions also playing significant roles in influencing these dynamics.

Accumulation, translocation and transformation of artificial sweeteners in plants: A critical review.

Artificial sweeteners (ASs) have become an increasingly significant concern as an emerging contaminant. The widespread utilization has given rise to environmental consequences that are progressively harder to disregard. ASs infiltrate both aquatic and terrestrial ecosystems through the discharge of wastewater effluents and the application of manure and biosolids. These compounds can be absorbed and accumulated by plants from soil, water and the atmosphere, posing potential risks to ecological systems and human health. However, limited data available on plant absorption, translocation, and metabolism of ASs hinders a comprehensive understanding of their impact on ecosystem. This study aims to comprehensively summarize the global distribution of ASs, along with elucidating patterns of their uptake and accumulation within plants. Furthermore, it seeks to elucidate the pivotal factors governing ASs absorption and translocation, encompassing hydrophilicity, ionic nature, plant physiology, and environmental conditions. Notably, there remains a significant knowledge gap in understanding the biodegradation of ASs within plants, with their specific degradation pathways and mechanisms largely unexplored, thereby necessitating further investigation. Additionally, this review provides valuable insights into the ecotoxicological effects of ASs on plants. Finally, it identifies research gaps and outlines potential avenues for future research, offering a forward-looking perspective on this critical issue.

Effects of various laser cladding materials on the tribological properties of damaged wheel treads under various temperatures and humidities

Laser cladding technology is used to repair damaged wheels and plays an important role in prolonging their service life. Additionally, the temperature and humidity of the environment have important effects on the operation of the repaired wheels. In this study, widely used 316L and 420 stainless steel alloy powders were selected as cladding materials, and three environmental conditions (25℃-RH60%, 50℃-RH60%, and 50℃-RH90%) were set according to changes in temperature and humidity in different areas of China. Friction and wear tests were performed under different temperature and humidity conditions on a damaged wheel after local repair by laser cladding. The results clearly show that there are demarcated equiaxed and directional columnar grain regions in the 316L cladding, whereas there are uniform plate and strip martensite structures in the 420 cladding, which are well formed by the metallurgical bonding of the wheel substrate. From 25℃-RH60% to 50℃-RH90%, the friction coefficient, plastic deformation thickness, and wear rate of the wheel–rail tended to decrease. However, the wear rates of the 420-coated wheels increased as the environmental conditions increased from 25°C-RH60% and 50°C-RH60%, and the wear rates of the corresponding rail samples remained high. The main forms of surface damage are fatigue cracks and material spalling. With increasing temperature and humidity, the damage to the bonding zone between the cladding and substrate surface decreases. The damage to the cladding profile is caused mainly by cracks at different angles and spalling pits. In the 25°C-RH60% environment, cracks initiate in the profile of the bonding zone and propagate along the plastic rheological line to the interior of the material. In comparison, the locally repaired wheel with 316L stainless steel alloy powder as the laser cladding material has better tribological properties and is more suitable for repairing damaged wheels.

A model for h24 simulation of photovoltaic solar panels temperatures at any environmental condition

A model for h24 simulation of photovoltaic solar panels temperatures at any environmental condition

Strengthening the evidence for seasonal intertidal exploitation in Mesolithic Europe and new insights into Early Holocene environmental conditions in the Bay of Biscay from the oxygen isotope composition of Phorcus lineatus (da Costa, 1778) shells

Marine molluscs have been exploited by human societies since prehistoric times. Such practices have often resulted in large accumulations of shell remains in archaeological sites that offer unique information on biological, ecological and cultural aspects of human interaction with coastal systems in the past. In this study, stable oxygen isotope (δ18O) analysis was carried out on archaeological shells of Phorcus lineatus (da Costa, 1778) from the Mesolithic shell midden site of J3 (northern Iberian coast) to determine the seasonality of intertidal collection. The results indicate a consistent pattern of winter exploitation, supporting the emerging view that collections were governed by cost-benefit and management principles that are now widespread documented in other coastal Mesolithic sites in Europe. The consistent seasonal collections of P. lineatus during colder months can be taken as evidence of specie-specific management strategy to optimize yield while preserving local populations for future exploitation. Our results reinforce the view that European hunter-gatherers developed ecological knowledge on specific animal resources that persisted over large geographic areas. Additionally, from a palaeoenvironmental perspective, the sea surface temperatures (SST) inferred from δ18O values derived from mollusc shells (SSTδ18O) indicate that coastal marine waters during the Early Holocene in the southern Bay of Biscay were warmer than those of today. These environmental conditions are evaluated in relation to changes in insolation and ocean currents over time.

Enhancing milk-based drinks with lyophilized guar gum-coated cyanidin-3-O-glucoside-loaded nano-nutriosomes: Physicochemical and antioxidant characterizations.

Cyanidin-3-O-glucoside (C3G) is a flavonoid compound recognized for its diverse biological properties. It is considered one of the most promising flavonoids due to its potential health benefits. Still, its use in functional foods, particularly beverages, is limited due to degradation and instability under various environmental conditions. Recent advancements involving novel freeze-dried guar gum-coated nano-nutriosome (FD-GG-NS) carriers have demonstrated effective strategies to address these challenges. The purpose of this work was to develop and evaluate a novel freeze-dried guar gum-coated nano-nutriosomes that would improve the physicochemical stability and antioxidant activity of C3G in milk-based beverages. The results exhibited that C3G was successfully encapsulated in freeze-dried NS and GG-C3G-NS, with good encapsulation efficacy (>91.02 %) and particle sizes varied from 175.27 to 186.60 nm within a respectable range of PDI (<0.3). Firstly, to investigate the optimum concentration 0.4 % was shown to be the best concentration due to improved stability and dietary fiber content. The FD-GG-C3G-NS in milk drinks improved the color, turbidity, ζ-potential, and sensory assessment while declining apparent viscosity and acidity with improved antioxidant activity during storage for 15th days at 4 °C. Thus, integrating C3G into functional dairy drinks using guar gum-coated nano-nutriosomes has broad prospects in the food industry.

Latitudinal changes in blubber fatty acids of the South American sea lion along the Southeast Pacific Coast.

The composition of marine mammal blubber is influenced by factors such as diet and environmental conditions. Here, we investigate the thermal influence on fatty acid composition and degree of unsaturation in the blubber of 151 South American sea lions (Otaria byronia). Samples were collected at ten locations along the Chilean coast and spanned a latitudinal range of approximately 2500km, an arc of 23°. We found a significant latitudinal gradient in the biochemical composition of sea lion blubber. At higher colder latitudes the endogenous fatty acids in the blubber were more unsaturated, as indicated by the desaturation index. In cold conditions the modification of fatty acids from saturated to unsaturated improves fluidity of cell membranes, which is important for thermal insulation. Thus, the higher degree of unsaturated endogenous fatty acids at higher latitudes may help sea lions maintain thermal balance in colder environments. For the dietary-sourced fatty acids however, we found the opposite latitudinal pattern, here the overall degree of unsaturation decreases with latitude. The lower proportion of polyunsaturated fatty acids in blubber at higher latitudes may be influenced by the sea lion's dietary choices. Additionally, the presence of extremely high levels of 18:2n-6 in some sea lions south of 40°S, values more typical of terrestrial origin, suggests they consumed farmed salmon. The observed variation in fatty acid profiles across the latitudinal gradient implies that differences in fatty acid composition are not solely attributed to dietary variation, but potentially also to endogenous metabolism in response to environmental conditions.

Spatial distribution of bacteria in response to phytoplankton community and multiple environmental factors in surface waters in Sanggou Bay.

Coastal bays link terrestrial and oceanic carbon reservoirs and play important roles in marine carbon cycles. Particulate organic carbon (POC) produced by phytoplankton is a major autochthonous carbon source in coastal bays. Previous studies on the fate of POC produced by phytoplankton mainly focused on the relationship between phytoplankton and zooplankton in classic food webs, while our knowledge on the roles of bacterioplankton is still limited, particularly in bays under highly intensive aquaculture activities. Here, we investigated bacterial community structure, and the influence of environmental factors and phytoplankton biomass and community structure based on samples collected in August 2022 from Sanggou Bay, a typical aquaculture bay in northern China. Environmental conditions, phytoplankton and bacterial community structure differed significantly between different aquaculture areas, showing higher relative abundance of Synechococcus sp. in the mixing area of shellfish and kelp culture (Area II) than the shellfish culture area (Area I). In contrast, Marivita cryptomonadis was more abundant in Area I, associated with elevated dissolved inorganic nitrogen (DIN), POC, POC/PN (the molar ratio of POC to particulate nitrogen) and sterol-derived total phytoplankton biomass. The strong correlation between total phytoplankton biomass and particle-associated bacteria indicated the important role of this bacterial fraction in processing organic compounds produced by phytoplankton. Significant correlations between bacterial community composition and POC/PN suggested more organic carbon potentially entering detrital biomass pools in Area I compared to Area II. Our results suggest that spatial distribution patterns of bacterial community structure were regulated by multiple abiotic and biotic factors and had a profound impact on the fate of organic carbon under highly intensive aquaculture activities in Sanggou Bay.

Artificial light at night reduces predation and herbivory rates in a nearshore reef.

Artificial light at night (ALAN) is an escalating anthropogenic stressor that can affect ecological communities over a range of spatial scales by altering key ecological processes, such as predation and herbivory. Shallow subtidal reefs are highly diverse and productive habitats that are vulnerable to ALAN. We investigated rates of consumption by fish (predation and herbivory) under different light treatments (ALAN, dark and daylight conditions) using standardised bioassay methods, i.e. squidpops and Ulva pops in situ. We also used GoPros to record predator identity, number of strikes and time to strike in ALAN and daylight treatments. Contrary to previous studies, we found that predation and herbivory rates were significantly lower in ALAN treatments than in daytime and dark treatments. The highest predation and herbivory rates were observed in daytime treatments. The identity of predator species, time to strike and number of strikes also differed between daytime and ALAN treatments. Due to low light conditions, dark treatments were not filmed. Our findings suggest that ALAN can alter predation in unexpected ways, depending on the environmental conditions and species affected. Future coastal management strategies need to account for light pollution as a major stressor to preserve valuable ecological resources.

Sustainable Hull maintenance strategies in Baltic Sea region through case studies of RoPax vessels.

Determining optimal maintenance strategies in unique maritime environments like the Baltic Sea is challenging, as it should consider various aspects, including ship characteristics and environmental conditions. This study employs the decision support tool HullMASTER (Hull MAintenance STrategies for Emission Reduction) to assess the life cycle costs of different hull maintenance scenarios for RoPax vessels in the Baltic Sea. Findings indicate that optimal hull management can save operators up to €9.3 million and reduce socio-environmental damage costs by €7.9 million over ten years compared to a less proactive baseline. Notably, biofouling pressure decreases from the high-salinity Skagerrak and Kattegat to the low-salinity Baltic Proper, emphasizing the need for tailored maintenance strategies. Among the coatings analyzed, non-biocide foul-release coatings are the most sustainable choice, reducing emissions to the ocean and the atmosphere. These findings will provide practical guidelines for sustainable hull management strategies, contributing to enhanced operational efficiency and marine environmental protection.

N-acyl-homoserine-lactones as a critical factor for biofilm formation during the initial adhesion stage in drinking water distribution systems.

The N-acyl-homoserine-lactone (AHLs)-mediated quorum sensing (QS) system is crucial for the coordination of microbial behaviors within communities. However, the levels of AHLs in biofilms in drinking water distribution systems (DWDSs) and their impact on biofilm formation remain poorly understood. Herein, we simulated DWDSs via biofilm reactors to explore the presence and influence of AHLs during the initial stages of biofilm formation on pipe walls. Glass, polypropylene random copolymer (PP-R) and stainless steel (SS) were used as the coupon materials and the three parallel experimental groups were set up and named accordingly. The glass material is considered to form biofilms only minimally and is therefore used as a negative control. By day 30, the concentration of AHLs in biofilm phase in both PP-R group and SS group reached 1200-1800ng/L. The predominant AHLs were C6-HSL, C8-HSL, and C10-HSL, with a significant positive correlation between AHLs and biofilm biomass. Metagenomic analysis revealed that microbes exhibiting significant differences among the three groups all demonstrated notable correlations with AHLs. Subsequent analysis of QS genes revealed that the genes associated with AHLs biosynthesis and QS receptors were more abundant in the PP-R and SS groups with biofilm formation. Additionally, we analyzed the abundance of genes related to cell motility, transmembrane transport, tricarboxylic acid cycle, and genetic information synthesis. The co-occurrence network indicates that these processes exhibit a strong correlation with QS genes. This study demonstrates the pivotal role of AHLs in microbial communication during the initial stages of biofilm formation in DWDSs and indicates that the regulatory pathways and mechanisms of AHLs may vary under different environmental conditions.

Temperature Requirements Can Affect the Microbial Composition Causing Sour Rot in Grapes.

Sour rot (SR) is a late-season non-Botrytis rot affecting grapevines, resulting from a complex interplay of microorganisms, including non-Saccharomyces yeasts and acetic acid bacteria. Nonmicrobial factors contributing to disease development encompass vectors (e.g., Drosophila spp.), the presence of wounds or microcracks on grape berry surfaces, and environmental conditions during berry ripening. The microbial complexes within SR-affected grapes exhibit variability among different bioclimates and seasons, with certain microorganisms predominating under specific conditions. This study examined the influence of environmental conditions on the microbiome composition associated with SR-affected grape bunches, utilising data from 41 locations across three distinct Italian bioclimates. We selected nine yeast and two bacterial species frequently isolated from sour-rotted grapes for analysis. The growth responses of these microorganisms to temperature were assessed by categorising them into four ecophysiological clusters. Furthermore, we analysed the distribution of these microorganisms and their respective ecophysiological clusters across the three bioclimates. The results indicate that the microbiomes involved in SR can vary according to the bioclimatic conditions of the grape-growing area. Further research is required to comprehend the ecological requirements of these microorganisms, define their ecological niches to understand their geographical distribution and epidemiology, and enhance SR management strategies.

Genome-wide association mapping and genomic prediction analyses reveal the genetic architecture of grain yield and agronomic traits under drought and optimum conditions in maize

BackgroundDrought is a major abiotic stress in sub-Saharan Africa, impacting maize growth and development leading to severe yield loss. Drought tolerance is a complex trait regulated by multiple genes, making direct grain yield selection ineffective. To dissect the genetic architecture of grain yield and flowering traits under drought stress, a genome-wide association study (GWAS) was conducted on a panel of 236 maize lines testcrossed and evaluated under managed drought and optimal growing conditions in multiple environments using seven multi-locus GWAS models (mrMLM, FASTmrMLM, FASTmrEMMA, pLARmEB, pKWmEB, ISIS EM-BLASSO, and FARMCPU) from mrMLM and GAPIT R packages. Genomic prediction with RR-BLUP model was applied on BLUEs across locations under optimum and drought conditions.ResultsA total of 172 stable and reliable quantitative trait nucleotides (QTNs) were identified, of which 77 are associated with GY, AD, SD, ASI, PH, EH, EPO and EPP under drought and 95 are linked to GY, AD, SD, ASI, PH, EH, EPO and EPP under optimal conditions. Among these QTNs, 17 QTNs explained over 10% of the phenotypic variation (R2 ≥ 10%). Furthermore, 43 candidate genes were discovered and annotated. Two major candidate genes, Zm00001eb041070 closely associated with grain yield near peak QTN, qGY_DS1.1 (S1_216149215) and Zm00001eb364110 closely related to anthesis-silking interval near peak QTN, qASI_DS8.2 (S8_167256316) were identified, encoding AP2-EREBP transcription factor 60 and TCP-transcription factor 20, respectively under drought stress. Haplo-pheno analysis identified superior haplotypes for qGY_DS1.1 (S1_216149215) associated with the higher grain yield under drought stress. Genomic prediction revealed moderate to high prediction accuracies under optimum and drought conditions.ConclusionThe lines carrying superior haplotypes can be used as potential donors in improving grain yield under drought stress. Integration of genomic selection with GWAS results leads not only to an increase in the prediction accuracy but also to validate the function of the identified candidate genes as well increase in the accumulation of favorable alleles with minor and major effects in elite breeding lines. This study provides valuable insight into the genetic architecture of grain yield and secondary traits under drought stress.