High Temperature Water Research Articles

Tolerance of free-living larval stage of a parasite from coastal mining areas in northern Humboldt Current to copper pollution at low and high temperatures.

Metal pollution is a worldwide problem and one of the greatest threats to ecosystem integrity due to its toxicity, persistence, and bioaccumulation in biological systems. Anthropogenic pollution impacts marine organisms and host-parasite dynamics, with the northern Chilean coast experiencing elevated copper levels in marine waters and sediments due to mining activities. In this study, we assessed the effects of exposure to copper concentrations at low and high-water temperatures on the survival and longevity of the marine parasite Himasthla sp. cercariae (Trematoda: Digenea) using the snail Echinolittorina peruviana as its first intermediate host. Snails were collected from intertidal rocky pools in northern Chile (23°S). To assess parasite survival and longevity, cercariae were collected from a pool of infected snails, and their mortality was recorded every 6 hours until all cercariae were dead. In a preliminary experiment conducted at 19°C, cercariae were exposed to different copper concentrations (0.2, 1.5, 3.0, and 6.0 mg/L) for 78 hours. Cercariae showed tolerance to copper. However, at the higher copper concentration (6 mg/L), survival was negatively impacted (50%) at 54 hours. In contrast, at the lower concentration (0.2 mg/L) and in the control group, cercariae sustained a 73-90% survival rate even after 54 hours. Based on these findings, we conducted subsequent experiments involving two copper treatments (0.2 and 3.0 mg/L) and two temperatures (14 and 22°C). Survival and longevity were significantly higher at lower temperature and copper concentration (14°C and 0.2 mg/L). Conversely, at higher temperature and copper concentration (22°C and 3 mg/L), survival and longevity decreased to only 66 hours. Our results show that Himasthla sp. cercariae tolerated most copper concentrations, with vulnerability observed primarily in high water temperatures, indicating an adverse effect on cercariae performance. This study contributes valuable insights into how parasites respond to environmental pollution, in marine ecosystems influenced by anthropogenic activities.

The oxidation-dissolution behavior of Cr-coated Zr alloy in high temperature water

The corrosion and dissolution behavior of Cr-coated Zr alloy were investigated in high temperature water under varying dissolved oxygen (DO) and temperatures. Results demonstrate that the oxidation and dissolution rates of Cr coatings increase significantly with higher DO levels and temperature, while the Zr substrate remains unaffected by DO concentration. At DO levels below 10 ppb, Cr coatings exhibit high stability, but at 300 ppb DO, rapid corrosion/dissolution and spallation occur. The electrochemical potential (ECP) shifts in response to temperature and DO, driving the dissolution mechanism through three distinct region: steady-state, field-assisted dissolution (FAD), and complete dissolution. During the FAD period, a porous nanocrystalline Cr2O3 layer with residual Cr forms, characterized by non-uniform dissolution due to preferential oxidation at grain boundaries and microstructural defects. The soluble HCrO4− ions form at the base of the porous layer, followed by partial recrystallization at the surface, leading to the development of a thin Cr2O3 crystalline layer.

Patterns and Drivers of CO2 and CH4 Fluxes in an Urbanized River Network and Their Response to Restoration

AbstractCarbon evasion from urban river networks becomes increasingly significant as urbanization accelerates. However, there remains a limited understanding of the overall carbon emission impact integrating CO2 and CH4 dynamics, particularly in response to ecological restoration efforts. In this study, we investigated patterns of fluvial CO2 and CH4 diffusive fluxes across an urban river network in Wuxi, China. Our results reveal that water quality variables, especially dissolved oxygen (DO) and phosphorus content, predominantly influence the variability of carbon emissions. These factors exhibit a stronger correlation with CO2 emissions compared to CH4, indicating a net increase in carbon emissions as water quality deteriorates. Seasonally, higher water temperatures, phosphate levels, and lower DO concentrations lead to increased carbon emissions during summer months. Spatially, areas with lower carbon emissions (averaged 86 mmol m−2 d−1 CO2 and 0.13 mmol m−2 d−1 CH4) are primarily situated near the lake and in river sections where significant water quality improvements have been achieved through ecological restoration efforts. Cluster analysis shows that over 60% of high‐carbon emission (averaged 162 mmol m−2 d−1 CO2 and 1.21 mmol m−2 d−1 CH4) sites in the study area have undergone ecological restoration, suggesting potential for further carbon emission reduction through enhanced restoration practices. Our findings underscore the importance of implementing carbon reduction strategies such as nutrient removal and aeration for oxygenation within water ecological restoration initiatives. Effective matching of restoration strategies holds further potential for mitigating carbon emissions from urban river networks.

Conversion of Monosaccharides into Aromatic Compounds over a Charcoal-supported Platinum Catalyst in High-temperature Water

Conversion of Monosaccharides into Aromatic Compounds over a Charcoal-supported Platinum Catalyst in High-temperature Water

Under the microscope: Reduced Activation Ferritic Martensitic Steel Eurofer-97 Following Ion-Irradiation and High-Temperature High-Pressure Water Exposure

Under the microscope: Reduced Activation Ferritic Martensitic Steel Eurofer-97 Following Ion-Irradiation and High-Temperature High-Pressure Water Exposure

Anhydrous microwave synthesis as efficient method for obtaining model advanced glycation end-products

IntroductionAdvanced glycation end-products (AGEs) are capable of stimulating oxidative stress and inflammation. This study investigates the synthesis of medium crosslinked AGEs (the most optimal form of AGEs because of soluble in water, used in many assays as markers) and their biochemical properties.MethodsOne of model protein–myoglobin from horse heart muscle (MB) and a chosen respective glycation factor – D-melibiose (mel), acrolein (ACR), D-glucose (glc), 4-hydroksynonenal (4HNE), trans-2-nonenal (T2N), methylglyoxal (MGO) – were subjected to high temperature water synthesis (HTWS) and high temperature microwave synthesis in anhydrous conditions (HTMS). The syntheses were deliberately carried out in two different conditions to check whether adding an additional energy source (microwaves) while lowering the temperature and shortening the reaction time would allow for more effective obtaining of medium-cross-linked AGEs, monitored with SDS-PAGE. Products were analyzed using fluorescence measurements, Enzyme-Linked Immunosorbent Assay (ELISA) and immunoblotting tests and electrophoretic mobility shift assay to evaluate their ability to activate nuclear factor kappa-light-chain-enhancer (NF-κB).ResultsMedium cross-linked AGEs were more efficiently obtained in HTMS. Fluorescence was high for MB-ACR, MB-T2N and MB-glc products. Anti-MAGE antibodies showed reactivity towards MB-mels of HTMS and HTWS, and the MB-4HNEs from HTMS. HTWS products, apart from MB-ACR, did not activate NF-κB, whereas MB-ACR, MB-4HNE, MB-mel, and MB-T2N products of HTMS strongly activated this factor that indicates their strong pro-inflammatory properties.ConclusionHTMS is a fast and efficient method of synthesizing medium cross-linked AGEs.

A probabilistic assessment of ship blackout incident with Fault Tree Analysis into (FTA) Bayesian Network (BN)

Blackouts in maritime activities can cause propulsion loss and dangerous maritime conditions. Bayesian risk analysis is applied to ship blackout incidents in this study to improve understanding and reduce risks. Using Fault Tree Analysis (FTA), a Bayesian Network (BN) model incorporates fuel quality, lubricating oil quality, sensor error, injector error, and mechanical defects to estimate blackout probability. The model analyses how hazards and their interactions affect this situation using probabilistic inference. Sensitivity analysis identifies variables that affect blackout probabilities and prioritises risk mitigation solutions. Based on prior and posterior probabilities, ‘Automatic Voltage Regulator Failure’ (0.03 prior, 0.17 posterior), ‘Rotor Mechanical Fault’ (0.03 prior, 0.15 posterior), and ‘High Cooling Water Temperature’ (0.03 prior, 0.13 posterior) are the top three blackout causes. Other significant variables include ‘Switchboard Line Failure,’ ‘Faulty Fuel Pump,’ ‘Rotor Open Circuit,’ and ‘Temperature Sensor Failure’ in relative amounts. Bayesian risk analysis can identify and minimise marine blackout concerns, giving decision-makers a comprehensive framework for informed decision-making and proactive risk management. This research emphasises blackout accidents’ importance, improving maritime transportation safety and reliability.

Improving the performance of hot water storage tanks using chimney type heaters

Hot water storage tanks (HWST) are high energy consumption devices. One way of reducing energy consumption is improving thermal stratification of the HWST. Improving thermal stratification will supply hot water faster for users, reduce the energy they consumed, increase efficiency in solar collectors or heat exchanger. In this work, the electrically heated HWST is led under investigation to improve the thermal stratification by imposing a chimney over the heating element to accelerate the top layer temperature by natural convection. Various tank sizes (38, 50, 62, and 75 litres) were investigated. The chimney height (HC), chimney diameter (DC) and chimney natural flow area (Df= 9.5, 2.5 and 1.5 cm) were also analysed to find the optimal chimney. The experiments revealed that using chimney in the HWST will accelerate the natural circulation to the upper layer in the storage tank. This will reduce the amount of energy required to perform the same operation without a chimney. Using chimney type heaters (CTH) in the HWST is favorable especially when tanks volume to heating element power increases. The entropy generation and distorted exergy of the system were improved by using CTH, thus the available reversable work increases. High hot water temperatures were attained in a shorter time which favorite such HWST. Higher efficiencies in case of solar heat collectors (due to lower cold-water temperatures in the bottom layers). Dynamic mode of CTHHWST represents a significant issue which needs detailed investigation which is currently under investigation.

Study on Performance Deterioration of Asphalt and Asphalt Mixtures Containing Mafilon under Internal Salt Freeze-Thaw Cycles

The purpose of this work is to determine the implications of internal salt freeze-thaw cycles on performance deterioration to asphalt and asphalt mixtures containing Mafilon (MFL). The deterioration to different numbers of F-TCs and different MFL contents on asphalt properties and mechanism were investigated by physical properties tests and microcosmic tests. Then the damages of road performance indexes of asphalt mixtures containing different MFL contents were studied by road performance tests. The experimental results show that asphalt containing MFL after F-TCs has a remarkable decline in ductility and penetration, while growth in softening point. Internal salt F-TCs are most damaging to the cryogenic properties of asphalt. Chemical reactions and salt aging effects occur in salt F-TCs, raising the glass transition temperature of asphalt. Road performance tests indicate the deterioration of internal salt F-TCs to high temperature stability and water stability is the most pronounced, with 29.18% and 21.78% reduction, respectively.

Evaluating a Polyhouse Pond-based Aquaculture Production System for Cultivating Neolissochilus hexagonolepis (Chocolate Mahseer) in the Agro-climatic Conditions of Meghalaya, Northeast India

This study evaluated a polyhouse pond aquaculture system (PPAS, 200m2) for cultivating chocolate mahseer (Neolissochilus hexagonolepis) under Meghalaya’s agro-climatic conditions. Over two years, chocolate mahseer growth, survival, and biomass production in PPAS were compared against a conventional open pond aquaculture system (OPAS, 200m2). PPAS demonstrated substantial advantages, with fish exhibiting 34.6% higher final weight (112.24 ± 7.10g vs 83.38 ± 9.91g), 34.8% greater daily weight gain (0.31 ± 0.02 g/day vs 0.23 ± 0.03 g/day), 7.8% higher specific growth rate (1.10 ± 0.04 %/day vs 1.02 ± 0.08 %/day), and 16.1% better survival rate (83.85 ± 5.02% vs 72.20 ± 6.85%) compared to OPAS. Consequently, PPAS total fish biomass (941.97 ± 91.20 kg/ha) was 56.5% greater than OPAS (601.84 ± 90.60 kg/ha). PPAS maintained an average 2.4°C higher water temperature, with a 3.2°C difference during winter. Despite higher initial investment (₹ 85,000 vs ₹ 50,000) PPAS net profit (₹ 6,872) was substantially higher than OPAS (₹ 2,432) due to increased biomass. This innovative system mitigates environmental constraints, meriting further research for enhancing economic viability and long-term sustainability in adverse climatic regions.

Effect of Constant Cyclic Stress Coupling on the Fatigue Behavior of 304LN Stainless Steel.

The stress state of the primary circuit main pipeline is very complex mixed constant stress and periodic cyclic stress during the operation of nuclear power plants, which often affects the failure behavior of the stainless steel (SS) pipe. The fatigue behavior of 304LN SS under mixed constant stress and cyclic stress was investigated, and it was found that the coupling effect of constant stress and cyclic stress has a significant collaborative acceleration on the fatigue behavior. The research results showed that the cracks in the 304LN SS did not propagate even after 78 days under both constant load conditions of 5 KN and 7.5 KN, while the crack growth rate (CGR) of the specimen increased by about an order of magnitude when coupled with a cyclic fatigue load. The fatigue life of 304LN SS was the longest under 200 °C high-temperature water, and its life was roughly the same under 250 °C and 300 °C water. In a 300 °C high-temperature water environment, the fatigue life under the coupling of constant stress and cyclic fatigue stress is significantly lower than that under symmetric cyclic stress alone. There is a synergistic acceleration effect on the fatigue life of 304LN SS when constant stress is coupled with periodic cyclic stress, which is attributed to the combined effect of a corrosion environment and mechanical factors.

Interseismic Locking of the Xiaojiang Fault May Be Controlled by Pore Fluid Pressure

AbstractAlthough fault locking state has been widely acquired with space geodetic observations, the mechanisms controlling fault locking are poorly known. Here, we infer the locking state of the Xiaojiang fault with a viscoelastic deformation model and integrated GNSS data, based on which we probe the mechanism that may control the locking pattern of the fault. Our results reveal four highly locked asperities along the Xiaojiang fault, which are separated by weak locking zones. Relying on the inferred locking degree and spring water temperature along the fault, we construct a model to connect the fault hydraulic conductivity with the cooling process of upwelling water. Model results suggest that high spring water temperature correlates with high hydraulic conductivity. Further, we use an experimental law to infer that the obtained high hydraulic conductivity may associate with high pore fluid pressure, which in turn weakens the fault frictional strength and leads to weak locking.

Comparative Hydrogen Production Routes via Steam Methane Reforming and Chemical Looping Reforming of Natural Gas as Feedstock

Hydrogen production is essential in the transition to sustainable energy. This study examines two hydrogen production routes, steam methane reforming (SMR) and chemical looping reforming (CLR), both using raw natural gas as feedstock. SMR, the most commonly used industrial process, involves reacting methane with steam to produce hydrogen, carbon monoxide, and carbon dioxide. In contrast, CLR uses a metal oxide as an oxygen carrier to facilitate hydrogen production without generating additional carbon dioxide. Simulations conducted using Aspen HYSYS analyzed each method’s performance and energy consumption. The results show that SMR achieved 99.98% hydrogen purity, whereas CLR produced 99.97% purity. An energy analysis revealed that CLR requires 31% less energy than SMR, likely due to the absence of low- and high-temperature water–gas shift units. Overall, the findings suggest that CLR offers substantial advantages over SMR, including lower energy consumption and the production of cleaner hydrogen, free from carbon dioxide generated during the water–gas shift process.

Immunity Induction in Catfish (Clarias gariepinus) with Feed Containing Red Ginger Extract after High Temperature Treatment

This study aims to evaluate the effect of feeding feed containing red ginger extract on the immunity and survival of catfish (Clarias gariepinus) fingerlings exposed to high temperature conditions. The research was carried out experimentally with a Completely Randomized Design (CRD) consisting of four treatment doses of red ginger extract (A: 0 ml/kg, B: 30 ml/kg, C: 40 ml/kg, D: 50 ml/kg) and three replications. Parameters observed included survival rate, white blood cell count, red blood cell count. The results showed that the addition of red ginger extract to feed was able to increase catfish survival by up to 90% at a dose of 50 ml/kg. A significant increase in the number of white blood cells and red blood cells in fish given red ginger extract indicates a better immune response. Red ginger extract has proven effective in helping fish adapt to thermal stress by increasing immunity and resistance to high water temperatures.

Treatment of turbine blades in electric power stations by adding nano oxides to the matrix material (Al80-Ni20)

Abstract A base material of Al80-Ni20 was used and mixed with variable proportions of Nano chromium oxide (Cr2O3) at percentages of 2, 4, 6, 8 and 10%, as well as with Nano magnesium oxide (MgO) at percentages of 2, 4, 6, 8 and 10%. These mixtures were then applied using the thermal spraying method with a flame. This particular method is commonly used for repairing cracks and protecting turbine blades in electric power stations from external corrosion. However, it is important to note that this method may face challenges when exposed to high-temperature water vapour, salts and other working conditions experienced by turbine blades. Samples were prepared by thermally sintering the coating at 1000 °C for two hours. Various measurements were performed to assess the structural properties using a scanning electron microscope (SEM), as well as other physical tests such as porosity, hardness, adhesion strength and frictional wear. The SEM analysis revealed that the presence of 10% Cr2O3 resulted in a surface that was uniformly free from external defects, whereas the addition of MgO led to a less homogeneous surface. The physical data obtained indicated a preference for Cr2O3, as evidenced by the porosity results (4.5%) observed after thermal sintering at 10%, as well as the hardness (193 HV), adhesion strength (40 MPa) and wear (2.90 × 10−5 g cm−1) measurements. Moreover, the analyses of the properties of MgO under the same conditions included porosity (10%), hardness (155 HV), adhesion strength (35 MPa) and wear (5.50 × 10−5 g cm−1).

Full-spectrum solar water decomposition for hydrogen production via a concentrating photovoltaic-thermal power generator-solid oxide electrolysis cell system

This study introduces a novel solar-powered concentrating photovoltaic-thermal power generator-solid oxide electrolysis cell system designed to enhance hydrogen production efficiency by optimizing both electrical and thermal energy utilization. The system incorporates a thermal power generator to convert excess high-temperature thermal energy into electrical energy, addressing energy losses associated with high-temperature water electrolysis. Thermodynamic analysis shows that the integration of the thermal power generator improves energy and exergy efficiencies to 0.60 and 0.52, while lowering the optimal operating temperature to 1173 K. The system’s efficiency is sensitive to the proportion of electrical energy supplied by the thermal power generator, with an optimal range identified between 0.1 and 0.2. Higher temperatures improve hydrogen production and efficiency, but increased voltage negatively impacts thermodynamic efficiency. These findings demonstrate that the proposed system offers substantial improvements over conventional solar hydrogen production methods, making it a promising candidate for sustainable hydrogen production. Further research will focus on system integration, material costs, and scalability for commercial use.

Soil Bacteria from the Namib Desert: Insights into Plant Growth Promotion and Osmotolerance in a Hyper-Arid Environment

The Namib Desert is characterized by a number of abiotic stresses, including high temperature, high salinity, osmotic pressure, alkaline pH, and limited water availability. In such environments, dry soils typically exhibit a low water potential, scarce nutrients, and high concentrations of dissolved ions, collectively creating a challenging habitat for microbial life. In this study, 89 bacterial isolates belonging to 20 genera were identified. Bacteria demonstrated significant osmotolerance, with some strains thriving at polyethylene glycol (PEG) concentrations exceeding 20%. Furthermore, these bacteria demonstrated halotolerance, high pH tolerance, and capacity to produce plant growth-promoting (PGP) traits under conditions of osmotic stress. Osmotolerant bacteria exhibited higher proficiency in siderophore production, potassium solubilization, and phosphorus solubilization, all of which are critical for supporting plant growth in nutrient-scarce and stressful environments, such as deserts. However, alginate production was higher in isolates that were less osmotolerant, indicating the potential for a compensatory mechanism in strains that were more sensitive. These findings highlight the complex strategies employed by desert bacteria to survive and support host plants in extreme environments. The present study not only enhances our understanding of microbial adaptations in arid ecosystems, but also provides important information for the development of potential applications for these bacteria in the reclamation of arid land and agricultural practices aimed at improving crop resilience to abiotic stress.

Unveiling the synergistic effect of thermal aging and irradiation corrosion on the passivation performance and stress corrosion cracking of 308 L stainless steel under high-temperature water environment

This study investigated coupling of thermal aging with irradiation corrosion, and carried out the microstructure and electrochemical characterization of 308 L stainless steel (SS). The passivation performance of 308 L SS was studied under the simulated pressurized water reactor (PWR) environmental condition and its stress corrosion cracking (SCC) performance was tested under thermal aging-irradiation conditions. The experimental results indicate that thermal aging results in spinodal decomposition of δ-ferrite, giving rise to G-phase precipitate and carbide precipitate formation at δ/γ-phase interface, whereas irradiation causes Cr depletion and Ni enrichment at the interface. Both thermal aging and irradiation lead to the decreased corrosion resistance of 308 L SS. Under coupling conditions of the two, severe Cr loss occurs at the phase boundary, which leads to severe corrosion on δ/γ phase boundary and also reduces SCC resistance of 308 L SS.

Silicon–carbon superhydrophobic nano-structure for next generation semiconductor industry

Abstract Superhydrophobic surfaces are important in waterproof applications that withstand harsh chemical exposure, ultraviolet radiation, and heat. Surface energy modification of the surface, such as silanization or (fluoro)polymer coatings, increases the hydrophobicity of the nanostructure. The present study follows a bilayer architecture that turns hydrophilic silicon into a superhydrophobic one. The first step creates a unique silicon–graphene hybrid structure on the silicon surface by coating graphene on the P-type silicon substrate. In the second step, low surface energy material (a combination of hexadecyltrimethoxysilane and hexamethyldisilazane) is coated by the dip coating process. This study investigates the durability of superhydrophobicity under severe mechanical, thermal, and chemical conditions. High-temperature tolerance and water jet tests are also performed. The present work also involves the study of coating regeneration. This approach can be applied to all shapes and sizes of silicon–graphene surfaces and is proven to be excellent in the semiconductor industry.

Pengaruh Kualitas Air terhadap Keanekaragaman Plankton di Bozem: Analisis Parameter Fisik, Kimia, dan Biologi Ekosistem Perairan

Water quality plays an important role in maintaining the balance of aquatic ecosystems, including the abundance and diversity of plankton. This study aims to analyze the effect of various water quality parameters such as temperature, dissolved oxygen (DO), carbon dioxide (CO2) levels, Biochemical Oxygen Demand (BOD), pH, brightness, and turbidity on plankton diversity in Bozem. Data were obtained from eight observation stations with water quality parameter measurements and plankton sampling. The results showed that the water quality in Bozem was not optimal, with low DO values ​​(1.79 mg/L), high water temperatures (average 31.05°C), and low brightness (0.30 m), which contributed to the decline in plankton abundance. A total of 39 plankton genera were identified, with Synedra as the most dominant genus. Poor water quality inhibits plankton growth, which can impact the balance of the food chain in these waters. This study shows the importance of better water quality management to maintain the sustainability of aquatic ecosystems in Bozem. This study also contributes to the understanding of the multifactorial interactions between water quality parameters and plankton.