Severe Environmental Conditions Research Articles

Cozy den or winter walk: the effects of climate and supplementary feeding on brown bear winter behavior

AbstractHibernation is a key adaptation for coping with unfavorable climatic conditions and low food availability in areas with severe winter conditions. While understanding the physiology and phenology of this adaptation has received considerable attention, comparatively little information is available on how hibernation will be affected by changing climate conditions. We used GPS telemetry data from 20 free‐ranging brown bears monitored over 31 winters between 2007 and 2022, to identify behavioral strategies of bears during winter. We applied behavioral change point analysis to quantify brown bears’ hibernation phenology in a population close to the bear's southern latitudinal range limit in Europe where supplementary food is available to bears year‐round. We observed winter behavior patterns that varied across age and reproductive classes but also within individuals between winters. Among 31 winter events, we registered six cases in which bears exhibited a single hibernation/stationary period and 19 events where hibernation was split into up to five stationary periods. Moreover, six winter events did not show behaviors consistent with hibernation and individuals remained partly or completely active throughout winter. The movement of these active bears decreased with increasing snow depth. In addition, these winter‐active bears showed higher fidelity to supplementary feeding sites during the winter period compared to the rest of the year. Our data suggest that an abundance of human‐provided food resources during winter may facilitate the emergence of different wintering strategies in brown bears. Furthermore, supplemental feeding sites in combination with predicted mild winters and prolonged natural food availability suggest that the use of hibernation as an energy‐saving strategy to overcome severe environmental conditions may decrease in the future.

Different Scenarios for the Origin and the Subsequent Succession of a Hypothetical Microbial Community in the Cloud Layer of Venus.

The possible existence of a microbial community in the venusian clouds is one of the most intriguing hypotheses in modern astrobiology. Such a community must be characterized by a high survivability potential under severe environmental conditions, the most extreme of which are very low pH levels and water activity. Considering different scenarios for the origin of life and geological history of our planet, a few of these scenarios are discussed in the context of the origin of hypothetical microbial life within the venusian cloud layer. The existence of liquid water on the surface of ancient Venus is one of the key outstanding questions influencing this possibility. We link the inherent attributes of microbial life as we know it that favor the persistence of life in such an environment and review the possible scenarios of life's origin and its evolution under a strong greenhouse effect and loss of water on Venus. We also propose a roadmap and describe a novel methodological approach for astrobiological research in the framework of future missions to Venus with the intent to reveal whether life exists today on the planet.

Quantitative analysis of the spatial distance between autophagy-related membrane structures and the endoplasmic reticulum in Saccharomyces cerevisiae

ABSTRACT Macroautophagy/autophagy is the process by which cells degrade their cytoplasmic proteins or organelles in vacuoles to maintain cellular homeostasis under severe environmental conditions. In the yeast Saccharomyces cerevisiae, autophagy-related (Atg) proteins essential for autophagosome formation accumulate near the vacuole to form the dot-shaped phagophore assembly site/pre-autophagosomal structure (PAS). The PAS then generates the phagophore/isolation membrane (PG), which expands to become a closed double-membrane autophagosome. Hereinafter, we refer to the PAS, PG, and autophagosome as autophagy-related structures (ARSs). During autophagosome formation, Atg2 is responsible for tethering the ARS to the endoplasmic reticulum (ER) via ER exit sites (ERESs), and for transferring phospholipids from the ER to ARSs. Therefore, ARS and the ER are spatially close in the presence of Atg2 but are separated in its absence. Because the contact of an ARS with the ER must be established at the earliest stage of autophagosome formation, it is important to know whether the ARS is tethered to the ER. In this study, we developed a rapid and objective method to estimate tethering of the ARS to the ER by measuring the distance between the ARS and ERES under fluorescence microscopy, and found that tethering of the ARS to the ER was lost without Atg1. This method might be useful to predict the tethering activity of Atg2. Abbreviation: ARS, autophagy-related structure; Dautas, automated measurement of the distance between autophagy-related structures and ER exit sites analysis system; ERES, endoplasmic reticulum exit site; PAS, phagophore assembly site/pre-autophagosomal structure; PCR, polymerase chain reaction; PG, phagophore/isolation membrane; prApe1, precursor of vacuolar aminopeptidase I; Qautas, quantitative autophagy-related structure analysis system; SD/CA; synthetic dextrose plus casamino acid medium; WT, wild-type

A Corrosion- and Repair-Based Reliability Framework for Offshore Platforms

Offshore platforms are important infrastructures that often face severe environmental conditions, such as corrosion, throughout their lifetime. This can continuously decrease their structural robustness. Despite the availability of many anti-corrosion strategies, there is still a need for a sound management scheme that can systematically address the lifetime operation of offshore platforms under corrosion. To address this, the work here proposes a corrosion- and repair-based reliability framework for the lifetime operation of offshore platforms. A fixed offshore platform is designed based on current design codes for severe environmental conditions in a given return period, and the effect of corrosion on the structure’s serviceability is modeled. The results show that the extent of the corrosion depth and damage in different years highly affects the ability of a repair to restore a damaged element to its original design strength. The results also show that the residual reliability of the structural members under the splash zone becomes almost zero after the first 10 years of the operation period, implying that these members require quick repair strategies. This study establishes a management program for fixed offshore platforms subjected to long-term corrosion by performing reliability analyses on the components of the platforms and evaluating the maintenance of the components in the splash zone. In the absence of commonly accepted contemporary industry practice standards, this study proposes a corrosion growth model based on API-RP-2A, DNV, and NORSOK standards that can effectively evaluate code-based structural designs. The framework developed here can help offshore platform owners in their decision-making process for corrosion-based safety analysis.

Machine Learning Approaches for Predicting the Ablation Performance of Ceramic Matrix Composites

Materials used in aircraft engines, gas turbines, nuclear reactors, re-entry vehicles, and hypersonic structures are subject to severe environmental conditions that present significant challenges. With their remarkable properties, such as high melting temperatures, strong resistance to oxidation, corrosion, and ablation, minimal creep, and advantageous thermal cycling behavior, ceramic matrix composites (CMCs) show great promise as a material to meet the strict requirements in these kinds of environments. Furthermore, the addition of boron nitride nanoparticles with continuous fibers to the CMCs can offer thermal resistivity in harsh conditions, which will improve the composites’ strength and fracture toughness. Therefore, in extreme situations, it is crucial to understand the thermal resistivity period of composite materials. To forecast the ablation performance of composites, we developed six machine learning regression methods in this study: decision tree, random forest, support vector machine, gradient boosting, extreme gradient boosting, and adaptive boosting. When evaluating model performance using metrics including R2 score, root mean square error, mean absolute error, and mean absolute percentage error, the gradient boosting and extreme gradient boosting machine learning regression models performed better than the others. The effectiveness of machine learning models as a useful tool for forecasting the ablation behavior of ceramic matrix composites was effectively explained by this study.

The Research Progress on the Interaction between Mammalian Gut Microbiota and the Host's Metabolism Homeostasis during Hibernation.

Hibernating mammals confront seasonal and harsh environmental shifts, prompting a cycle of pre-hibernation feeding and subsequent winter fasting. These adaptive practices induce diverse physiological adjustments within the animal's body. With the gut microbiota's metabolic activity being heavily reliant on the host's diet, this cycle's primary impact is on this microbial community. When the structure and composition of the gut microbiota changes, corresponding alterations in the interactions occur between these microorganisms and their host. These successive adaptations significantly contribute to the host's capacity to sustain relatively stable metabolic and immune functions in severe environmental conditions. A thorough investigation into the reciprocal interplay between the host and gut microbiota during hibernation-induced adaptive changes holds promise for unveiling new insights. Understanding the underlying mechanisms driving these interactions may potentially unlock innovative approaches to address extreme pathological conditions in humans.

An agent-based modelling framework for performance assessment of search and rescue operations in the Barents Sea

AbstractIn recent years, the increase in Arctic offshore activities has raised concerns about the search and rescue (SAR) operations as mitigative measures to ensure the safety of shipping and cruise activities. Performing SAR operations in the remote Arctic offshore environment is exceptionally challenging due to the severe environmental conditions, including low temperatures, high waves, strong winds, heavy snow showers, sea ice, spray icing, dense fog, limited visibility, and polar low pressures. Moreover, the scarcity of port infrastructure along the Arctic coastline exacerbates the difficulties faced during SAR operations. Tackling the aforementioned challenges necessitates a comprehensive modelling framework for analysis of SAR operations in the Arctic that is able to consider the dynamics and uncertain nature of Arctic harsh environmental conditions, and the constraints imposed by the limited capacity of Arctic SAR infrastructure. To this aim, this paper proposes an agent-based modelling (ABM) framework to assess the performance of SAR operations while tackling such challenges in the Arctic. A Monte Carlo simulation approach is used to model the dynamics and uncertainty of weather and sea conditions using historical data, using which some severity levels are determined. Expert judgement process is then used quantify the impacts of such severity levels on the performance of rescue agents, and thus, on the total rescue time. To validate the proposed framework, an illustrative case in the Norwegian Barents Sea is considered, where the performance of SAR infrastructure is examined under different rescue scenarios. According to the results of this paper, the total rescue time is the longest during December to February, and the shortest rescue time is associated with months May to August. Some recommendations are further proposed to improve the performance of SAR infrastructure in the Barents Sea.

Identification of corrosion factors in blast furnace gas pipe network with corrosion big data online monitoring technology

To mitigate the accelerated corrosion of blast furnace gas pipelines induced by severe environmental conditions, this study has established an extensive high-throughput sensor system in the field. It leverages corrosion big data technology to investigate the corrosion factors affecting industrial gas pipelines and to precisely analyze the influence of related variables. The results indicated that temperature reduction is the driving factor that causes increased pipeline corrosion. On one hand, temperature fluctuations impact the evaporation and condensation of moisture in the tube. On the other hand, temperature fluctuations, in conjunction with corrosive gases, exhibit significant coupling effects, resulting in more severe corrosion. In addition, critical points for relative humidity and temperature are evident. When humidity exceeds 50%, corrosion in the pipe begins to increase, reaching its peak at 70%. The increase in temperature has a slowing effect on pipeline corrosion, reaching a peak value at 40°C. The response of corrosion rate to the concentration of corrosive gases follows a linear pattern. Based on these observations, we propose an effective corrosion control scheme.

Study of partial discharge and breakdown phenomena at triple junctions under various conditions of pressure and temperature

The presence of a triple junction constitutes a potential source of failure in many industrial applications. The reinforcement of the local electric field due to differences in relative permittivity facilitates the formation of partial discharges (PD) which weaken the insulation system and eventually lead to complete breakdown. Additionally, severe environmental conditions (temperature, pressure) associated with certain applications (e. g. nuclear or aeronautical sector) should be considered because of their influence on discharge phenomena occurring at triple junctions. In this study, the behaviour of partial discharge inception voltage (PDIV) and of breakdown (flash-over) voltage (BIV) is compared in the case of a triple junction with an aluminium oxide disc as a solid insulator when the system is heated up to 400 °C. While the PDIV decreases strongly for temperatures above 300 °C, this effect disappears for the BIV. It is proposed that this behaviour is due to the fact that relative permittivity of the aluminium oxide disc increases with temperature at low frequencies, but remains relatively stable at high frequencies, regardless of the temperature.

Slip‐resistant connections subjected to freeze‐thaw cycles

AbstractThere are many examples of steel structures subjected to severe environmental conditions with bolted connections directly exposed to climatic agents such as steel bridges, mining transfer towers, wind towers etc. In this experimental research, non‐slip joints with M16 and M20 bolts have been studied. The specimens were subjected to fourteen 12 h freeze‐thaw cycles, with periodic immersion in water and temperature oscillation. Subsequently, the connections were subjected to a slip test under monotonic load. The results were compared with other equal joints not subjected to freeze‐thaw cycles and kept at room temperature for the same time. Some interesting conclusions are extracted from this piece of research. It was observed that freeze‐thaw cycles negatively affect the slip resistance of non‐slip joints with GB+ZE surfaces, even with a slight increase in clamping force. Samples with SR and GB surfaces increase in their slip resistance was observed.

Durability Properties of Macro-Polypropylene Fiber Reinforced Self-Compacting Concrete.

Concrete is one of the most commonly used construction materials; however, its durability plays a pivotal role in areas where the concrete is exposed to severe environmental conditions, which initiate cracks inside and disintegrate it. Randomly distributed short fibers arrest the initiation and propagation of micro-cracks in the concrete and maintain its integrity. Traditional polypropylene fibers are thin and encounter the problem of balling effects during concrete mixing, leading to uneven fiber distribution. Thus, a new polypropylene fiber is developed by gluing thin ones together, forming macro-polypropylene fibers. Thus, different amounts of fibers, 0-1.5% v/f with an increment of 0.5% v/f, are used in different grades of concrete to study their impact on durability properties, including resistance to freezing and thawing cycles, sulfate, and acid attacks. A total of 432 cube samples were tested at 28, 56, and 92 days. The results reveal that the maximum durability, in terms of compressive strength loss, is noted with a fiber content of 1% with improved resistance of 72%, 54%, and 24% against freeze-thaw cycles, sulfate attack, and hydrochloric acid attack, respectively, at 92 days. Thus, the resulting fiber-reinforced concrete may be effective in areas where these extreme exposure conditions are expected.

Biological reclamation of post-technogenic landscapes of Yakutia: problems and prospects

In the context of intensive industrial development in the Republic of Sakha (Yakutia), the issue of restoring technogenically disturbed areas is becoming increasingly relevant. Technogenic landscapes formed during the extraction of mineral deposits often have negative effects on the environment, and severe environmental conditions hinder the restoration of ecosystems affected by industrial activities. This study synthesized the long-term research results of scientists from the Research Institute of Applied Ecology of the North named after Prof., Dr. Savvinov (NEFU) on the study of succession and soil restoration processes in post-technogenic landscapes of placer deposits in the basins of the Anabar River and the Aldan River, as well as at the diamond and coal ore deposits in the Mirninsky, Aldansky and Neryungrinsky regions of Yakutia. Our study demonstrated that the effective restoration of technogenically disturbed landscapes is relevant to the use of seeds and planting materials from local flora in the biological stage of reclamation. On the dumps of ore deposits composed of rocks that are slowly weathered under hypergenesis conditions, effective restoration can be achieved only with the formation of technogenic soil. Due to the deficit of (decipher) PPP and (decipher)PSP, it is necessary to create a technology for the biological reclamation of disturbed lands with the use of alternative materials.

Large-Scale Fabrication of Tunable Sandwich-Structured Silver Nanowires and Aramid Nanofiber Films for Exceptional Electromagnetic Interference (EMI) Shielding.

The recent advancements in communication technology have facilitated the widespread deployment of electronic communication equipment globally, resulting in the pervasive presence of electromagnetic pollution. Consequently, there is an urgent necessity to develop a thin, lightweight, efficient, and durable electromagnetic interference (EMI) shielding material capable of withstanding severe environmental conditions. In this paper, we propose an innovative and scalable method for preparing EMI shielding films with a tunable sandwich structure. The film possesses a nylon mesh (NM) backbone, with AgNWs serving as the shielding coating and aramid nanofibers (ANFs) acting as the cladding layer. The prepared film was thin and flexible, with a thickness of only 0.13 mm. AgNWs can easily form a conductive network structure, and when the minimum addition amount was 0.2 mg/cm2, the EMI SE value reached 28.7 dB, effectively shielding 99.884% of electromagnetic waves and thereby meeting the commercial shielding requirement of 20 dB. With an increase in dosage up to 1.0 mg/cm2, the EMI SE value further improved to reach 50.6 dB. The NAAANF film demonstrated remarkable robustness in the face of complex usage environments as a result of the outstanding thermal, acid, and alkali resistance properties of aramid fibers. Such a thin, efficient, and environmentally resistant EMI shielding film provided new ideas for the broad EMI shielding market.

Optimal Design of Rotor Sails Based on Environmental Conditions and Cost

Rotor sails are one of the promising solutions to reducing the energy consumption and CO2 emissions of ships. Previous studies focused on how rotor sails affect ship dynamics and energy consumption. In the present study, an optimization-based workflow was proposed to find the optimal design of a rotor sail based on given environmental conditions for a target ship. Since the performance of a rotor sail depends on both operational conditions and the design of the rotor sail, a two-level optimization problem was proposed to separate the optimization of operational conditions and rotor sail design. At the operational level, the spin ratio of a given rotor sail was optimized at each time step under different environmental conditions. Then, the design of the rotor sail was optimized on the design level considering the initial cost of rotor sails and the average operational cost of the ship depending on the environmental conditions and their probabilities. The reductions in energy consumption of ships having optimal rotor sail designs, considering 5-year, 10-year, 15-year, and 20-year investment plans were found to be 0.34%, 2.7%, 3.91%, and 4.29%, respectively. When more severe environmental conditions were assumed for the 10-year investment plan, the diameter of the rotor sail increased and the reduction in energy consumption increased from 2.7% to 4.06%.

Numerical Investigation of a Floating-Type Support Structure (Tri-Star Floater) for 9.5 MW Wind Turbine Generators

A numerical investigation of floating-type substructures for wind turbine generators was conducted by using time-domain simulation. A Tri-Star floater for 8–10 MW generators, which was developed by Samsung Heavy Industries (SHI), was chosen as the floating substructure. To make the anchor system, catenary mooring lines, considering redundancy, were installed on the floater. The main sources of external force on the wind turbine generator are wind, waves, and currents. To consider severe environmental conditions, Design Load Cases (DLCs) 1.6 and 6.1 of the IEC guidelines (IEC 61400-3-1) were chosen. From the measured environmental data for the installation site, the main parameters for the simulation conditions were obtained. The tilt angle and horizontal movement of the floater and the mooring tension for the different mooring systems were checked. The response of the floater during the failure of the mooring was also studied, and the critical failure of the mooring was confirmed. During the failure of the mooring, the redundancy system worked well, in which the movement of the floater was constrained within the criteria for all scenarios.

Design consideration and recent developments in flexible, transparent and wearable antenna technology: A review

AbstractThe wearable technology and flexible electronics have been convoluted in modern technologies and many of applications especially insensors, biomedical, displays, solar panels, glasses, smart cities, integrated circuits, and wireless body area network (WBAN). They offer capability of mechanical deformation conditions mainly stretchable, bendable, foldable features and capable to severe environmental conditions. Nowadays, a device having lightweight, low‐profile, compact in size and flexible deployment on the system platforms is preferred. With the flexibility in the design of the antenna, they require flexible, robust, easy to wear, visually imperceptible, unobtrusiveness, and planar material for the realization. The characteristics of the wearable antenna may vary according to the material conductivity and their optical transparency, substrate selection and their thickness along with permittivity opted for and mechanical deformation behavior. Generally, the textile material is utilized to design the flexible wearable antenna due to material flexibility which can minimize the losses and enhance the antenna performance. Conversely, the visually imperceptible and flexible material is utilized to design transparent wearable antenna due to appropriate trade‐off between conductivity and optical transparency of the materials. For diverse WBAN applications, the flexible, transparent, and wearable antennas are utilized. This paper elaborates the comprehensive review and the state‐of‐the‐art research on the diverse categories of the wearable antennas based on the substrate characteristics such as flexibility and transparency. In addition, it provides the broad investigation of the flexible and transparent materials utilized to design wearable antennas and different tissue layers with their dielectric properties to develop the human multilayer phantom model.

Structure-function relationships in the nasal cavity of Arctic and subtropical seals

The heating and moistening of inhaled air, and the cooling and moisture removal from exhaled air, are crucial for the survival of animals under severe environmental conditions. Arctic mammals have evolved specific adaptive mechanisms to retain warmth and water and restrict heat loss during breathing. Here, the role of the porous turbinates of the nasal cavities of Arctic and subtropical seals is studied with this in mind. Mass and energy balance equations are used to compute the time-dependent temperature and water vapor profiles along the nasal passage. A quasi-1D model based on computed tomography images of seal nasal cavities is used in numerical simulations. Measured cross-sectional areas of the air channel and the perimeters of the computed tomography slices along the nasal cavities of the two seal species are used. The model includes coupled heat and vapor transfer at the air-mucus interface and heat transfer at the interfaces between the tissues and blood vessels. The model, which assumes constant blood flow to the nose, can be used to predict the temperature of the exhaled air as a function of ambient temperature. The energy dissipation (entropy production) in the nasal passages was used to measure the relative importance of structural parameters for heat and water recovery. We found that an increase in perimeter led to significant decreases in the total energy dissipation. This is explained by improved conditions for heat and water transfer with a larger complexity of turbinates. Owing to differences in their nasal cavity morphology, the Arctic seal is expected to be advantaged in these respects relative to the subtropical seal.

Marine Bacterial Community Structures of Selected Coastal Seawater and Sediment Sites in Qatar.

Severe environmental conditions can have a diverse impact on marine microorganisms, including bacteria. This can have an inevitable impact on the biofouling of membrane-based desalination plants. In this work, we have utilized indicator bacteria such as total coliform, fecal coliform, and Pseudomonas aeruginosa, as well as 16S rRNA sequencing, to investigate the impact of environmental conditions and spatial variations on the diversity of bacterial communities in the coastal waters and sediments from selected sites in Qatar. The concentration levels of indicator bacteria were affected by increasing temperatures and pH, and by decreasing salinity of seawater samples. Diversity indices and the molecular phylogeny demonstrated that Proteobacteria, Bacteroidetes, and Cyanobacteria were the dominant phyla in all locations. The most abundant operational taxonomic units (OTUs) at the family level were from Flavobacteriaceae (27.07%, 4.31%) and Rhodobacteraceae (22.51%, 9.86%) in seawater and sediment, respectively. Alphaproteobacteria (33.87%, 16.82%), Flavobacteria (30.68%, 5.84%), and Gammaproteobacteria (20.35%, 12.45%) were abundant at the species level in both seawater and sediment, while Clostridia (13.72%) was abundant in sediment only. The results suggest that sediment can act as a reservoir for indicator bacteria, with higher diversity and lower abundance compared to seawater.

Tomato salt-responsive pseudo-response regulator 1, SlSRP1, negatively regulates the high-salt and dehydration stress responses.

Under severe environmental stress conditions, plants inhibit their growth and development and initiate various defense mechanisms to survive. The pseudo-response regulator (PRRs) genes have been known to be involved in fruit ripening and plant immunity in various plant species, but their role in responses to environmental stresses, especially high salinity and dehydration, remains unclear. Here, we focused on PRRs in tomato plants and identified two PRR2-like genes, SlSRP1 and SlSRP1H, from the leaves of salt-treated tomato plants. After exposure to dehydration and high-salt stresses, expression of SISRP1, but not SlSRP1H, was significantly induced in tomato leaves. Subcellular localization analysis showed that SlSRP1 was predominantly located in the nucleus, while SlSRP1H was equally distributed in the nucleus and cytoplasm. To further investigate the potential role of SlSRP1 in the osmotic stress response, we generated SISRP1-silenced tomato plants. Compared to control plants, SISRP1-silenced tomato plants exhibited enhanced tolerance to high salinity, as evidenced by a high accumulation of proline and reduced chlorosis, ion leakage, and lipid peroxidation. Moreover, SISRP1-silenced tomato plants showed dehydration-tolerant phenotypes with enhanced abscisic acid sensitivity and increased expression of stress-related genes, including SlRD29, SlAREB, and SlDREB2. Overall, our findings suggest that SlSRP1 negatively regulates the osmotic stress response.

Sustainable development of ultra high-performance concrete using basil plant waste: Investigation at normal and extreme conditions

This study highlights the potential of using Basil plant (BP) waste as a viable and sustainable alternative to partially replace cement in ultra-high-performance concrete (UHPC), which can contribute to developing more sustainable and eco-friendly building materials. It investigates the effect of BP waste powder as an alternative solution on the performance of UHPC under high temperatures and severe environmental conditions. The aim was to achieve environmentally friendly green UHPC by minimizing cement content. The effect of using BP as a cement replacement with different percentages of 10 %, 20 %, 30 %, and 40 % by weight, on compressive strength, splitting tensile strength, sorptivity, and microstructure was evaluated. In addition, investigation was performed at different conditions of ambient temperature, high temperatures of 300 °C and 600 °C and severe environments subjected to chlorides and sulfates. The results showed that premixing UHPC with 30 % BP waste could improve compressive strength, with a maximum increase of 10 % at 28 days, and with decreasing sorptivity by 28 %. Additionally, the microstructure analysis revealed that incorporating BP waste leads to a denser structure and a reduction in the average pore size of the UHPC, which can enhance the durability and longevity of UHPC in construction applications. The findings of this study have important implications for the construction and building materials industry, which is under increasing pressure to adopt sustainable construction practices.