High Temperature Environment Research Articles

Assessing responses to heat in a range-shifting, nocturnal, flying squirrel

Abstract Over the last few decades North American flying squirrels (Glaucomys spp.) have experienced dramatic northward range shifts. Previous studies have focused on the potential effects of warming winter temperatures, yet the hypothesis that rising summer temperature had a role in these range shifts remained unexplored. We therefore sought to determine the effect of high environmental temperatures on the thermoregulation and energetics of flying squirrels in an area of the Northeast of North America with a recent species turnover. Unable to find a logistically feasible population of the northern species (Glaucomys sabrinus), we focused on Southern Flying Squirrels (G. volans). Using flow-through respirometry, we measured the relationship between metabolic rate, evaporative water loss, and body temperature at high ambient temperatures. We also measured core body temperature in free-ranging flying squirrels using temperature-sensitive data loggers. We detected no significant increase in metabolic rate up to ambient temperatures as high as 40 °C. However, evaporative water loss increased at temperatures above 36.2 °C. Free-ranging body temperature of flying squirrels followed a circadian pattern with a ~2 °C difference between active and resting phase modal body temperatures. Rest-phase body temperatures were influenced by environmental temperatures with higher resting temperatures observed on days with higher daily maximum ambient temperatures but not to an extent that energy or water costs were significantly increased during rest. We found that, due to a relatively high level of thermal tolerance, high ambient temperatures are unlikely to cause an energetic strain on Southern Flying Squirrels. However, these findings do not preclude negative impacts of high ambient temperatures on the northern species, and these may still play a role in the changing distributions of Glaucomys in North America.

A novel laser-EMAT ultrasonic longitudinal wave resonance method for wall thickness measurement at high temperatures

In this paper we propose a novel ultrasonic longitudinal wave resonance method for measuring the thickness of metal walls using a laser-electromagnetic acoustic transducer (Laser-EMAT). The method is based on the surface constraint mechanism (SCM) of the material and is expected to be capable of accurately detecting local thinning of metal walls in a non-contact manner and at high temperatures. Based on finite element analysis of laser-EMAT ultrasonic resonance measurement of aluminum alloy thickness, we investigated the effects of such key factors as SCM, irradiation parameters of laser source, and the size of EMAT receiving coil on the accuracy of thickness measurement (resonance frequency position) and on the amplitude of the resonance wave. Both numerical simulations and experiments are conducted to demonstrate that the measurement accuracy of the proposed method is not affected by SCM, irradiation laser source parameters, and EMAT receiving coil size, and that accurate detection of stepped aluminum plates with thickness thinning from 3.0 mm to 0.5 mm is achieved. Furthermore, we were able to perform rapid detection of aluminum thin plate thickness at 500 °C temperature with an EMAT lift-off of 5.0 mm and achieved a relative experimental error as small as 3.40 %. The results obtained in this study showed that the proposed method performed well in non-contact measurement of metal thinning in harsh environment of high temperature.

Optical, Structural, and Morphological Characterization of Titanium Oxide (TiO2) Nanoparticles from Laser Ablation in Deionized Water

In this research, we focus on the synthesis of titanium oxide (TiO2) nanoparticles using the Nd:Utilization of YAG laser pulse ablation technique in liquid environments, with pulse energies from 100 to 500 millijoules. The process employs a Nd:YAG laser operating at a frequency of 6 Hz and a wavelength of 1064 nm. (The TiO2 nanoparticles synthesized in this study could be used in different high-temperature environments, as they are characterized by favorable physical, chemical, and mechanical properties). The synthesized product was further treated by calcination for four hours at temperatures higher than 600°C which promoted crystalline structure in the lattice. Comprehensive analyses were carried out to determine the nanoparticles' features. Optical features were studied through UV-visible spectroscopy to examine the absorption spectrum and band gap. The detailed examination of the crystal and surface structures was done using X-ray diffraction and field emission scanning electron microscopy (FE-SEM), in order to obtain insight into the structural integrity and the morphology of the titanium oxide nanoparticles. The study provides a deeper insight into TiO2 nano particle production and their characteristics, thereby emphasizing their suitability for advanced material applications.

Thermal expansion, lattice vibration, and isotope effect on hydrogen diffusion in BCC Fe, Cr, and W from first-principles calculations.

Fe, Cr, and W are important elements in the alloys of in-reactor materials and operate in high-temperature environments with thermal expansion. Their tritium-impeding abilities are crucial to the radiation safety of various nuclear reactors. In this study, first-principles density functional theory is combined with quasi-harmonic approximation to evaluate factors that can affect the interstitial formation energy and diffusion coefficient of hydrogen isotopes in body-centered cubic (BCC) Fe, Cr, and W, including thermal expansion, metal host lattice vibrations, phonon density-of-states (pDOS) coupling diffusing atoms, and isotope effects. Calculation results indicate that the interstitial formation energy decreases as lattice expansion increases, whereas the jump barriers remain almost constant. Thermal expansion, host lattice vibration, and pDOS coupling minimally affect the diffusion coefficients of hydrogen isotopes in Fe, Cr, and W. The diffusion coefficient ratios between hydrogen isotopes are higher than the inverse ratio of the square root of the isotope mass at low temperatures. However, they decrease to the inverse ratio of the square root of the isotope mass at temperatures exceeding 800K. This study comprehensively investigates factors that affect the diffusion coefficients of hydrogen isotopes in BCC Fe, Cr, and W, thus providing a firm theoretical foundation for predicting the diffusion coefficients of tritium at different temperatures using protium/deuterium diffusion coefficients.

Effects of surface finishes, heat treatments and printing orientations on stress corrosion cracking behavior of laser powder bed fusion 316L stainless steel in high-temperature water

Stress corrosion cracking (SCC) of laser powder bed fusion 316 L stainless steel in oxygenated high-temperature water environments with chloride addition at 288 °C was studied. The influences of surface finishes (as-built, mechanically polished, Hirtisation® and shot peened), heat treatments (solution annealing at 1066 and 1150 °C and hot isostatic pressing) and the printing orientations on SCC were evaluated. Hirtisation resulted in a lower SCC susceptibility than as-built or polished surface while shot peening showed the lowest apparent SCC resistance. A high annealing temperature decreases SCC resistance. The effect of printing orientation is material and environment dependent.

From simulation to reality: CFD-ML-driven structural optimization and experimental analysis of thermal plasma reactors

Thermal plasma reactors offer an environment of high temperature, enthalpy, and reactivity, making them highly efficient for solid waste treatment and promising for clean energy production from municipal and industrial waste. Optimal geometrical parameters of the reactor can enhance waste treatment and reactor performance. This study presents a comprehensive analysis of 11 key geometrical parameters of a thermal plasma reactor. Utilizing CFD Fluent software, numerical simulations were conducted to generate a dataset. Subsequently, a predictive model focusing on the average temperature in the core melt zone was trained using six Machine Learning (ML) algorithms. The Particle Swarm Optimisation (PSO) algorithm optimized the hyperparameters of the Gradient Booster Regression (GBR) model, which was combined with a Genetic Algorithm (GA) to identify the reactor's optimal geometrical parameters. A DC arc plasma torch-solid waste thermal plasma reactor treatment system was established on this basis. The study also explored the effects of gasification coefficient, reaction temperature, and thermal plasma jet mode on system performance. Findings indicate that the PSO-GBR model achieved the highest prediction accuracy, with the temperature in the core reaction zone reaching 3621 K. The deviation between numerical simulations and machine learning predictions was a mere 1.3%. Enhancing syngas yield and energy efficiency is achievable by controlling reaction temperature and increasing the gasification coefficient. A laminar plasma jet mode, at equal power, provides a more effective reaction environment. The accuracy and reliability of the machine learning-driven regression model and optimization results are significant in guiding the optimal design of plasma reactors and advancing waste-to-energy conversion processes.

Damage behavior of carbon fiber electrothermal adhesive films after long-term electrothermal and hygrothermal aging treatment

Carbon fiber electrothermal adhesive films (CFEAFs) are the primary heating elements in wood-based electrothermal composites, and their durability is key to ensuring their long-term performance in high-temperature and high-humidity environments. In this work, the failure mechanism of CFEAFs was discussed by using long-term hygrothermal coupled treatments after electrothermal treatments at different power densities. The results showed that for CFEAFs which were only electrothermal treatment, increasing the power density produced more microscopic cracks on the surface, destroyed chemical bonds, and caused the thermal stability to decrease. The pyrolysis temperature decreased by 16.25 °C from 292.61 °C to 276.36 °C. Furthermore, under the coupled effects of electrothermal and hygrothermal treatments, the microscopic cracks on the CFEAFs became more obvious, and the surface roughness increased. The entry of water molecules further affected the chemical structure of the molecules inside CFEAFs, the maximum tensile strength of the whole material decreased by 65.6%, and the Tg decreased from 221.5 °C to 216.4 °C. These results provide a technical reference for using carbon fiber paper as the heating element of wood-based electrothermal composites to prevent electrical safety hazards during long-term cold-hot cycling.

Emission Spectra of Uranium Particulates at High Temperature.

The emission spectrum of micron-scale uranium particulates at high temperatures in the ultraviolet, visible, and near-infrared spectral regions is investigated using a heterogeneous shock tube. Temperatures from 3000 to 9000 K are characterized in an inert argon environment and with incremental amounts of added oxygen. Atomic line spectra do not emerge above the continuum emission spectrum until between 4500 and 5000 K in pure argon, and 6100 and 6600 K in 1% oxygen. For 5% oxygen, however, the threshold for atomic emission drops below 3800 K. Uranium monoxide molecular emission in the strongest visible band at 595.4 nm is not observed at any condition. Uncertainties in particle temperature determination in high-temperature shock tube environments are discussed, and limitations to such measurements are presented, such as those from experimental factors such as the powder loading method and expected detection limits of uranium species in relevant conditions.

A high-resolution characterization of surface film formed on alloys 800 and 690 exposed to chloride and thiosulfate-containing solution at 300°C

Purpose This paper aims to characterize the surface film formed on Alloys 800 and 690 in chloride and thiosulfate-containing solution at 300°C. Design/methodology/approach Alloy 800 and 690 were immersed in chloride and thiosulfate-containing solution at 300°C up to five days, and then the surface film was analyzed by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and energy dispersive X-ray spectrometers (EDX). Findings Through static immersion experiments in a high-temperature and high-pressure water environment, the alloy samples covered by surface film after five days of immersion were obtained. The morphology of the surface film was characterized at both horizontal and cross-sectional scales using SEM and focused ion beam-TEM techniques. It was observed that due to the influence of the quartz lining, the surface film primarily exhibited a bilayered structure. The first layer contained a significant amount of SiO2, with a higher content of metal hydroxides compared to metal oxides. The second layer was predominantly composed of Fe, Ni and Cr, with a higher content of metal oxides compared to metal hydroxides. Originality/value The results showed that the materials of the lining of the autoclave could significantly influence the film composition of the tested material, which should be paid attention when analyzing the corrosion mechanism at high temperature.

Microstructural study on in-situ high-entropy (NbMoTaWV)C reinforced nanocrystalline NbMoTaWVC refractory high entropy alloys prepared by mechanically alloying

Refractory high-entropy alloys (RHEAs) can be commonly regarded as the best candidates for potentially substituting for the nickel-based superalloys practically used in the areas of aviation and nuclear industry, which can significantly endure in high-temperature and harsh environment. In this work, a nanocrystalline NbMoTaWVC RHEA is successfully produced by mechanical alloying method and X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and spherical aberration corrected transmission electron microscopy (AC-TEM) are employed to systematically characterized the microstructural details of NbMoTaWV and NbMoTaWVC RHEAs mechanically alloyed powders. Our results can support the evidence that the observable minimum nanoparticle sizes of the NbMoTaWV and NbMoTaWVC RHEAs considerably decrease to approximately ∼100 nm. Furthermore, the average grain sizes are gradually refined and thus notably drop to around of 30–50 nm, and five elemental powders can be found to be homogeneously alloyed. The evidence can be confirmed that the order of solid solution may be proposed as follows: Nb → Mo → V → Ta → W. The chemical short-range order occurred at the local nanoscale of NbMoTaWV and NbMoTaWVC RHEAs. Meanwhile, further microstrutural analysis can demonstrate that NbMoTaWV and NbMoTaWVC RHEAs powders with ultrafined grain have a bcc phase structure and bcc + bct matrix phases combined with high-entropy tungsten carbides (NbMoTaWV)C and (NbMoTaWV)2C of nano-precipitated phases, respectively, suggesting that the martensitic transformation probably occurred. The NbMoTaWV and NbMoTaWVC RHEAs powders of locally crystal lattice distortion rates reached approximately 8.07% and 6.33%.

Development of Machining Device with Real-Time Visualization of Boundary Surface on Tool Rake Face and Cutting Chip

Analysis of cutting phenomena has been conducted for a long time and many researchers have elucidated the phenomena that may occur at the cutting-edge during machining; for example, built-up edges and welding phenomena on cutting edge. However, the existing research has focused on observing the tool and chips after machining, when the tool and work material have been cooled, and are under atmospheric pressure. Therefore, we consider that it is different from the phenomenon that occurs during cutting. Because the cutting edge of a tool is in a high-temperature and high-pressure environment during machining and is released from such an environment after machining, the cutting edge must be visualized to discuss the actual cutting phenomena. There have been research reports in the past that have visualized the backside of cutting chips; however, that experiment was far from actual cutting phenomena and was conducted at significantly low cutting speed. Thus, the visualization of the cutting phenomenon is physically extremely difficult at the cutting edge. Under such circumstances, this study developed a device that observed the behavior of the boundary surface between cutting chips and the rake face in real time from the backside of the rake face during machining. By using the developed device, we could visualize this phenomenon to acquire the data directly and visually, which can otherwise be grasped only indirectly. In this device, a camera was mounted on a tool holder, and a cutting tip made of a transparent material was used to observe rake face, cutting edge, and flank face which can be visualized during machining from the backside of the rake face within one field of view. This paper reports on the outline of the developed device, its method, and the results of experimental observation of the state of two-dimensional cutting using a lathe.

High temperature and mesostructure effect on aluminum foam compression responses

Closed-cell Al foam is widely utilized in high-temperature environments due to its high strength-to-weight ratio and considerable energy absorption capability. However, the mechanical properties depend on temperature and mesostructure. In this paper, the compressive responses of Al foams at temperatures ranging from 25 ℃ to 600 ℃ are investigated by experimental tests and two types of high-fidelity finite element simulations, including the X-ray computed tomography (CT) reconstructed model and Voronoi model. A deep learning approach is employed to remove tiny pores of CT slices, simplifying geometry features and improving the computational efficiency of the CT reconstructed model. A novel improved Voronoi model with high accuracy is proposed, considering the nonuniform distribution of cell wall thickness in actual closed-cell Al foams. A temperature-depend macro constitutive model is established and validated through the experimental and numerical results. This work reveals the influence mechanism of temperature and mesostructure on the mechanical responses of Al foams, and exhibits significant potential for the application of Al foams in high temperature environment.

Dingo optimization algorithm-based random forests model to evaluate the compressive strength of the concrete at elevated temperatures

The qualities of the materials employed to manufacture concrete are significantly impacted by high temperatures, which results in a noticeable decrease in the material’s strength characteristics. Concrete must be worked very hard and allowed to reach the required compressive strength (fc). Nevertheless, a preliminary estimation of the desired outcome may be made with an outstanding degree of reliability by using supervised machine learning algorithms. The study combined the Dingo optimization algorithm (DOA), Coot bird optimization (COA), and Artificial rabbit optimization (ARO) with Random Forests (RF) evaluation to determine the fc of concrete at high temperatures. The abbreviations used for the combined methods are RFD, RFC, and RFA, respectively. Remarkably, removing the temperature (T) parameter from the input set leads to a remarkable 1100% improvement in the effectiveness index (PI) and normalized root mean squared error (NRMSE), while causing a significant fall in the coefficient of determination (R2). The findings suggest that all RFD, RFC, and RFA have substantial promise in properly forecasting the fc of concrete at high temperatures. More precisely, the RFD algorithm demonstrated exceptional precision with R2 values of 0.9885 and 0.9873 throughout the training and testing stages, respectively. Through a comparison of the error percentages for RFD, RFC, and RFA in error-based measurements, it becomes evident that RFD exhibits an error rate that is about 50% smaller compared to that of RFC and RFA. This prediction is crucial for various industries and applications where concrete structures are subjected to elevated temperatures, such as in fire resistance assessments for buildings, tunnels, bridges, and other infrastructure. By accurately forecasting the compressive strength of concrete under these conditions, engineers and designers can make informed decisions regarding the material’s suitability and performance in high-temperature environments, leading to enhanced safety, durability, and cost-effectiveness of structures.

Intestinal microflora promotes Th2-mediated immunity through NLRP3 in damp and heat environments.

With the worsening of the greenhouse effect, the correlation between the damp-heat environment (DH) and the incidence of various diseases has gained increasing attention. Previous studies have demonstrated that DH can lead to intestinal disorders, enteritis, and an up-regulation of NOD-like receptor protein 3 (NLRP3). However, the mechanism of NLRP3 in this process remains unclear. We established a DH animal model to observe the impact of a high temperature and humidity environment on the mice. We sequenced the 16S rRNA of mouse feces, and the RNA transcriptome of intestinal tissue, as well as the levels of cytokines including interferon (IFN)-γ and interleukin (IL)-4 in serum. Our results indicate that the intestinal macrophage infiltration and the expression of inflammatory genes were increased in mice challenged with DH for 14 days, while the M2 macrophages were decreased in Nlrp3 -/- mice. The alpha diversity of intestinal bacteria in Nlrp3 -/- mice was significantly higher than that in control mice, including an up-regulation of the Firmicutes/Bacteroidetes ratio. Transcriptomic analysis revealed 307 differentially expressed genes were decreased in Nlrp3 -/- mice compared with control mice, which was related to humoral immune response, complement activation, phagocytic recognition, malaria and inflammatory bowel disease. The ratio of IFN-γ/IL-4 was decreased in control mice but increased in Nlrp3 -/- mice. Our study found that the inflammation induced by DH promotes Th2-mediated immunity via NLRP3, which is closely related to the disruption of intestinal flora.

Effect of ambient temperature on the adsorption performance of automotive activated carbon: An experimental and molecular simulation study

The ambient temperature is a non-negligible factor when evaluating the adsorption performance of automobile activated carbon. In this study, dynamic tests of butane adsorption on activated carbon were carried out at ambient temperatures of 293 K, 313 K, and 333 K. In addition, molecular simulation method was used to analyze the influence mechanism of temperature on the adsorption performance of activated carbon. The results show that the working capacity of automotive activated carbon decreases by 15.9% to 20.2% and the butane breakthrough time is shortened by 21.4% to 37.5%, as the ambient temperature is increased from 293 K to 333 K. In the high temperature environment, the thermal movement of the gas molecules is more intense so that the kinetic energy and diffusion coefficient of the butane molecules are increased. When activated carbon adsorbs multilayer butane molecules, the temperature increase mainly reduces the adsorption sites after the first adsorption layer (around 5.5 Å).

Mineralized structures from the Alhué mining district, Chile: Using fluid inclusions and textures

The Alhué mining district (AMD) of the Coastal Range in Central Chile is situated approximately 70 km southwest of the city of Santiago and hosted in stratified Jurassic and Early Cretaceous sequences which are common in central Chile. More than 79 faults and veins are recognized in the AMD hosted in andesites and tuffs with clear structural control showing two distinct trends. Precious‐metal mineralization locally extends over strike lengths of up to 1000 m along these structures with grades averaging at 5 ppm gold and 23 ppm of silver. In this study, a University of Chile – YAMANA GOLD joint research project was created to better understand this particular deposit and explore the origin of gold anomalies found in the district using drill core, mine, and surface samples. Wide internal variations in homogenization temperature and electrolytes were observed at all scales: on the district scale, in mineralized structures intersected in drill core, and in hand specimens. This variability may reflect the diversity of ore-forming conditions in the mining district in addition to the different processes (including fault motion over time) and geochemical components within the district. Textural analyses and fluid inclusion assemblages (FIA) provide evidence for boiling and flashing mechanisms at several localities. Raman spectroscopy and LA-ICP-MS techniques allowed a better characterization of the fluid composition and mineral paragenesis. The presence of gold (∼3.8 ppm) and silver (∼1424 ppm) in both vapor-rich only FIAs (i.e. that contain 99 % vapor) hosted in quartz and liquid-rich FIA hosted in sphalerite implies that gold was transported as sulfide and chloride complexes. The AMD shows a transition from a high temperature environment (sometimes containing calc-silicate minerals) to a low temperature (epithermal) system. This mineralization depended on the type of vein system which tend to be mineralized in strike slip faults e.g. Maqui and Lorena structures. The consequence of flashing documented at dilational jogs, structural intersections and fault bends was likely an important outcome leading to the precipitation of metals at the AMD.Coexisting liquid-rich and vapor-rich fluid inclusions contained in a FIA were observed at the deepest levels in the Chilco vein and the proportion of samples showing boiling increases with depth, indicating that additional precious metal resources may be present below current exploration depths. In summary, our new results reveal that gold, silver and base metal veins found at the AMD in Chile are unique hydrothermal polymetallic ore deposits that are structurally controlled and related to an orogenic environment. A general model for the AMD is one where high temperature fluids from deep crustal mafic magmatic systems, probably as products of a devolatilization and far-from-equilibrium conditions, reach subsurface conditions along faults and are mineralized along these faults. Because having a truly unique ore deposit in the geologic record is very unlikely, the AMD forms an important case study that helps understand structurally controlled ore deposits. Thus our work can form a model for future exploration in the AMD and provide insight into exploration in other sites in Chile and along continental margin settings worldwide, in both poorly characterized known deposits and at greenfield sites.

A novel sensor with excellent high-temperature performance for in-situ temperature measurement

Real-time access to critical information about system temperature variations is essential for evaluating system performance in some of the high-temperature and harsh environments. Given the technical difficulty of accurately obtaining the temperature of a high-temperature and harsh environment, a new sensor package structure is proposed. Combining ceramic sintering and isostatic pressure molding methods, the thermal junction is fixed in the temperature measurement end face of the alumina ceramic substrate, while the shell design threads play a role in fixing the sensor and preventing loosening. This paper conducted repeatability, upper-temperature limit, and high-temperature serviceability assessment tests on the sensor. The results show that the sensor maximum repeatability error is 2.4%. The sensor can continue to operate at 1200°C for more than 6 hours with no signal interruption and the upper limit of temperature measurement is 1307°C. The results demonstrate the feasibility and practicality of temperature measurement by this sensor in high-temperature and harsh environments.

Unleashing the potential of a new Y–BaTiO3/graphene oxide nanocomposites for boosting the dielectric stability at high temperature

This report presents a novel dielectric study of Ba1-xYxTi(1-x/4)O3 (x = 0, 2 %, 4 %, 6 %, and 8 %) with graphene oxide (GO) via sonication. BaTiO3 (BT) is a well-known ceramic material with excellent properties, and its temperature stability is crucial for high-temperature applications. However, there is a lack of scientific research exploring this stability at elevated temperatures. This research provides valuable insights into the stability of BaTiO3-Yttrium-based ceramics, particularly in conjunction with graphene (BYT@GO), paving the way for potential applications in high-temperature environments. The tetragonality of the structures was identified by powder X-ray diffraction. A uniform grain size was observed for BT@GO, However, BYT@GO (Y% = 2 %, 4 %, 6 %, and 8 %) exhibited a homogeneous morphology and dense microstructure, as observed by scanning electron microscopy. Dielectric measurements were conducted to evaluate the permittivity of the materials as a function of frequency at room temperature. All ceramics demonstrated stable permittivity and low dielectric losses as a function of frequency (<2 × 10−4 for BT@GO, 4 × 10−3 for BYT4%@GO, 6 × 10−3 for BYT6%@GO, and 8 × 10−3 for BYT8%@GO). In addition, BT@GO and BYT 8 %@GO exhibited exceptional dielectric stability at temperatures ranging from 20 to 300 °C.

Instantaneous thermal fracture behaviors of a bimaterial with a penny-shaped interface crack via generalized fractional heat transfer

In the high-temperature environment, a larger thermal expansion mismatch of a bimaterial leads to marked thermal stresses and interface crack growth. In this paper, a generalized fractional heat conduction model is used to determine the instantaneous thermal fracture behaviors of a bimaterial interface crack. An axisymmetric thermoelastic problem is solved with the aid of Goodier's thermoelastic displacement potential and Love's potential functions. A mixed initial-boundary value problem is then converted to a singular integral equation of second kind by using the Hankel and Laplace integral transforms. Numerical results of the intensity factors of heat flux and thermal stresses are evaluated using Stehfest's Laplace inversion scheme. The influence of fractional kernel functions with power and exponential law are analyzed, respectively, for aluminum-steel and steel-epoxy, respectively. The thermal stress intensity factors exhibit more wave-like behaviors based on Riemann-Liouville and Atangana-Baleanu models which is different from Caputo-Fabrizio and the complete diffusion model.

Bio-inspired superhydrophobic fiber membrane for oil-water separation and non-destructive transport of liquids in corrosive environments

Conventional polymer separation membranes or coatings suffer from poor separation performance and serious failure in highly corrosive environments, due to their low chemical and mechanical stability. Herein, a simple electrospraying and electrospinning strategy was used to prepare flexible superhydrophobic carbon fiber membranes (FSCFM). The wettability of FSCFM was improved by forming a lotus leaf-like hierarchical rough structure on its surface. The FSCFM exhibited an excellent permeation flux of immiscible oil-water mixtures (up to 15,800 L m-2 h-1) and water-in-oil emulsions (over 5,500 L m-2 h-1), while the separation efficiencies were always kept at more than 99% after 25 consecutive separations. Even in corrosive environments, its separation performance did not show any degradation. Notably, except for recovering floating oil under external driving forces with excellent cyclic stabilities, FSCFM was also able to transport various corrosive solutions with high efficiencies (99.9%). After multiple mechanical damages and bending cycles, the FSCFM remained superhydrophobic. It could also maintain its repellency in strong acids/bases, high salt solutions and even under high-temperature environments (94.5 °C). These superior properties make it a strong candidate for oil-water/emulsion separation and non-destructive transport of highly corrosive fluids.