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[Display omitted] Thermochromic dyes (TCDs) based on a three-component color change system suffer from solid rigidity and liquid leakage issues because of the intrinsic solid–liquid phase change performance, resulting in difficulty in temperature visualization applications for smart wearable fields. Despite considerable efforts in microencapsulation of thermochromic dyes, designing and fabricating essentially flexible thermochromic phase change films still need to be explored. Herein, a one-sided adhesive gradient-crosslinked thermochromic film is reported to address these issues to make a trade-off between stability and flexibility, excellent thermochromic performance, and temperature visualization. The thermochromic wearable films have been fabricated exploiting tea polyphenol thermochromic dyes, vinyl dimethylsiloxane, and hydrosilicone oil via the salt-template-assisted method and gradient crosslinking strategy, which have porous structures with an average pore size of 12.8 μm and a porosity of 28 %. Due to the spatial limiting threshold effect of the porosity structure, interconnected 3D polysiloxane porous networks can provide ample support for tea polyphenol thermochromic dyes and effectively prevent liquid leakage. Upon heating, the thermochromic film changes from blue to white with the K/S value decreasing from 7.69 to 0.78 and the Δ E * increasing from 2.7 to 16.1 at 610 nm, and the color-changing temperature is 42 °C. Gradient crosslinked thermochromic films exhibit excellent temperature-responsive color change properties, desirable one-side adhesion, and thermal energy storage, enabling multicolor temperature displays and temperature-controlled multilevel information transfer. [ABSTRACT FROM AUTHOR]

In the industry, liquid leakage can occur during accidental events. When liquids leak out of the container or reactor, they can harm creatures, humans, and the environment. A measurement technique that can visualize the leakage location within a reasonable budget is therefore required. This paper proposes a low-cost ultrasonic measurement to estimate the leakage point in the container or reactor. The measurement system utilizes only a single ultrasonic transducer and compact pulser/receiver. The basic ultrasonic velocity profiler (UVP) is used as the measurement algorithm. The concept operates with a small angle rotation on the measurement line. The velocity vector profile is then reconstructed, and the leakage point is estimated. The experimental demonstration was conducted in a rectangular water tank to simulate the leakage location. The measurement result was found to be reasonable, meaning the leakage location can be estimated from the vector profile obtained. [ABSTRACT FROM AUTHOR]

Highlights Micro-extrusion compression molding and surface modification were proposed for the mass fabrication of a superhydrophobic thermoplastic polyurethane sensor (TCGS). Inspired by scorpions, TCGS features Archimedean spiral crack arrays and micropores, achieving 218.13 sensitivity at 2% strain, a 4300% increase, and over 5000 usage cycles of durability. The robust superhydrophobicity of TCGS improves sensitivity and stability for detecting small-scale liquid leakage, allowing precise monitoring across various sizes and compositions while providing early warnings in various scenarios.

Highlights: Micro-extrusion compression molding and surface modification were proposed for the mass fabrication of a superhydrophobic thermoplastic polyurethane sensor (TCGS). Inspired by scorpions, TCGS features Archimedean spiral crack arrays and micropores, achieving 218.13 sensitivity at 2% strain, a 4300% increase, and over 5000 usage cycles of durability. The robust superhydrophobicity of TCGS improves sensitivity and stability for detecting small-scale liquid leakage, allowing precise monitoring across various sizes and compositions while providing early warnings in various scenarios. Liquid leakage of pipeline networks not only results in considerable resource wastage but also leads to environmental pollution and ecological imbalance. In response to this global issue, a bioinspired superhydrophobic thermoplastic polyurethane/carbon nanotubes/graphene nanosheets flexible strain sensor (TCGS) has been developed using a combination of micro-extrusion compression molding and surface modification for real-time wireless detection of liquid leakage. The TCGS utilizes the synergistic effects of Archimedean spiral crack arrays and micropores, which are inspired by the remarkable sensory capabilities of scorpions. This design achieves a sensitivity of 218.13 at a strain of 2%, which is an increase of 4300%. Additionally, it demonstrates exceptional durability by withstanding over 5000 usage cycles. The robust superhydrophobicity of the TCGS significantly enhances sensitivity and stability in detecting small-scale liquid leakage, enabling precise monitoring of liquid leakage across a wide range of sizes, velocities, and compositions while issuing prompt alerts. This provides critical early warnings for both industrial pipelines and potential liquid leakage scenarios in everyday life. The development and utilization of bioinspired ultrasensitive flexible strain sensors offer an innovative and effective solution for the early wireless detection of liquid leakage. [ABSTRACT FROM AUTHOR]

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Plunger lift is one of the commonly used processes for liquid extraction and gas production in gas wells. Owing to the gap between the plunger and the tubing wall, liquid leakage and gas channeling during the lifting process are inevitable. Liquid leakage reduces the amount of lifted liquid, and gas channeling is not conducive to the complete utilization of formation energy. Furthermore, the gas that breaks through the gap into the top of the plunger also hinders plunger movement. To address this problem, we used CFD to simulate plunger movement in the tubing and analyzed the influence of various factors, such as plunger velocity, pressure difference between the upper and lower ends, and plunger diameter, on liquid leakage and air channeling. The results indicated that when the plunger rises and drains the liquid, the plunger velocity increases, the leakage between the plunger and the tubing increases, and the gas channeling volume decreases. When the pressure difference between the upper and lower ends of the plunger increases, leakage loss is reduced. The larger the plunger diameter, smaller the interval between the plunger and the tubing, and smaller the less leakage loss. The results of the study validate the influencing factors of plunger lift leakage and gas channeling, optimizing the plunger structure and improving the efficiency of plunger lifting. [ABSTRACT FROM AUTHOR]

Owing to the advantages of non-volatility, outstanding fluidity and easy recyclability, ionic liquid-based electronics, such as thermometer, strain sensors and thermoelectric converters, have been growing as attractive alternatives to traditionally solid electronics. The fluidic character endows the ionic liquid-based circuit with self-healing ability, satisfying the needs of longer lifetime and less waste generation for electronics, while at the same time brings the risk of leakage. Avoiding the leakage without sacrifice of self-healing ability is one of the major challenges for constructing ionic liquid-based electronic devices. In this feature article, we summarize our recent progresses in developing two types of self-healing electrical devices based on ionic liquids with little risk of leakage. One type involves the encapsulation of ionic liquids in self-healing polymers, and the other type uses ionic polymers or free-standing ionic liquids which are successfully formulated as intrinsically conductive, self-healing, and recyclable electronic devices without additional encapsulation. In the end, a comprehensive outlook is prospected for the future development of ionic liquid-based self-healing electronics, which is expected to spur more innovative work in this field. [ABSTRACT FROM AUTHOR]

Abstract A novel Na 2 SO 4 @SiO 2 @Al 2 O 3 -SiO 2 phase change material doped aerogel composite (PDAC) using the sol-gel technique is prepared. This new kind of composite material is composed of a core-shell structured Na 2 SO 4 @SiO 2 phase change material (PCM) with high melting temperature and Al 2 O 3 -SiO 2 aerogel with high thermal resistance and low thermal conductivity. The effects of PCM amounts and heat treatment temperatures on the physicochemical properties of Na 2 SO 4 @SiO 2 @Al 2 O 3 -SiO 2 PDCA are investigated. X-ray diffraction (XRD) shows that when the mass percentage of Na 2 SO 4 @SiO 2 PCM powders increases to 36.7%, the peaks corresponding to Na 2 SO 4 can be well observed. The boehmite phase within Na 2 SO 4 @SiO 2 @Al 2 O 3 -SiO 2 PDAC can be transformed to γ-Al 2 O 3 via structural adjustment after heat treatment at 600 °C. The pore size distribution doesn't shift after 600 °C heat treatment, and the most probable pore diameter is at around 30 nm. Transmission Electron Microscopy (TEM) shows that the Na 2 SO 4 @SiO 2 PCM powders with diameters at around 500 nm can be effectively trapped and are homogeneously distributed within the aerogel matrix even after further heat treatment at 1000 °C, therefore, liquid leakage can be inhibited during melting process. The peak latent heat of Na 2 SO 4 @SiO 2 @Al 2 O 3 -SiO 2 PDCA can be as high as 153.84 J/g with the PCM mass percentage at 36.7%. The Brunauer-Emmett-Teller (BET) specific surface area increases from 419.3 m2/g to 630.6 m2/g due to structural adjustment, and then decreases to 277.7 m2/g caused by volume shrinkage. Thermal simulation results show that the total melting time can be 254.8 s, and development of the temperature distribution keeps well with that of the liquid fraction. The velocity distribution of the liquid PCM keeps at 0 due to the constraint of aerogel matrix. This Na 2 SO 4 @SiO 2 @Al 2 O 3 -SiO 2 PDAC can be a promising high temperature PCM in thermal energy storage applications. [ABSTRACT FROM AUTHOR]

Abstract Plunger lift is an economical method to solve the liquid loading problem in wells. Following our previous research (Zhao et al., 2018), which focused on the steady-state process of liquid leakage during lifting, the transient variations of plunger velocity, liquid leakage and stress conditions during plunger lifting process are investigated theoretically and experimentally in this paper. Based on the force analysis and finite difference method, the transient physical model for the mass and gas volume fraction of gas-liquid column above plunger is proposed. Combining the similarity experiments and infrared measuring technology, the proposed transient model is verified quantitatively with the relative deviation less than ±10%. The results show that both the liquid leakage and the gas volume fraction of gas-liquid column above plunger cannot be neglected during plunger lifting. The transient change rules of lifting differential pressure, plunger velocity, gas volume fraction of gas-liquid column and liquid leakage flow rate during lifting process are obtained. The influences of liquid loading condition and gas production rate on transient plunger lifting process are discussed. Through the dimensionless analysis, a dimensionless correlation for transient gas volume fraction of gas-liquid column is developed. Highlights • The transient physical model for liquid leakage during plunger lifting was proposed. • The effects of liquid leakage on transient plunger lifting process were analyzed quantitatively. • The operating and well condition parameters affecting transient fluid sealing during lifting were determined. [ABSTRACT FROM AUTHOR]

Microencapsulated composite material using Na 2 SO 4 as core and SiO 2 as shell for high temperature thermal energy storage is prepared. The effects of silica mass percentages within the Na 2 SO 4 @SiO 2 PCM composites on thermal conductivity, thermal stability, melting temperature, and latent heat are investigated. No new phases are formed during the encapsulation process. The spherical silica nanoparticles with diameters at around 300 nm are well decorated on the surface of Na 2 SO 4 . The PCM composite with 5.4% silica addition is determined as the optimal sample due to its excellent comprehensive properties. The inhibition of liquid leakage during melting can be effectively realized. The thermal conductivity of Na 2 SO 4 @SiO 2 PCM under high temperatures (600–800 °C) can be increased to 0.59 W/(m K), 0.62 W/(m K), and 0.87 W/(m K), respectively. The initial and peak melting temperatures of the Na 2 SO 4 @SiO 2 are tested at 885.20 °C and 887.91 °C, respectively. The latent heat is determined as high as 170.6 J/(g K), and the total heat storage density including latent and sensible heat with a temperature span of 100 °C is 390.6 J/g, and the mass loss is observed < 1% under 1000 °C. In addition, the latent heat loss percentage after 50 thermal cycle tests is ≤ 4.3%. [ABSTRACT FROM AUTHOR]

• Study aims at synthesizing solid–solid PCMs suitable for cooling pavements. • New formula of solid–solid PCMs were determined. • Innovatively consider if PCMs can withstand harsh conditions of pavements. • M_PU5 had slight deformation ratio of 0.23% after held at 200 °C for 2 h. • The prepared asphalt mixture slab containing M_PU5 could be cooled by 4.8 °C. Effective cool pavement technologies with using phase change materials (PCMs) are of great significance to alleviate Urban Heat Island (UHI) effect and improve the functionality, safety and service life of asphalt pavements. This study focuses on the development of polyurethanes (PUs) as solid–solid PCMs (s-s PCMs) that are suitable for asphalt pavement cooling utilizations. First, a range of PUs were synthesized through two-step polymerization reactions. Successful synthesis was confirmed by the Fourier transform infrared (FTIR) spectroscopy test. Next, characterizations were performed on the synthesized PUs. It is demonstrated that a PU with a larger isocyanate content usually sustains a higher temperature without liquid leakage. The applicable s-s PCM among the synthesized PUs is M_PU5 with 4,4′-diphenylmethane diisocyanate (MDI) as the isocyanate and the molar ratio of MDI and polyethylene glycol (PEG) being 5, due to its desirable latent heat storage capacity of 93.5 J·g−1 and phase change temperatures of 36–48.3 °C, excellent thermal stability and reliability, and its strong ability to withstand harsh conditions of asphalt pavements. Finally, the feasibility of M_PU5 for actively cooling asphalt pavements has been verified by outdoor test. The investigated results provide a basis and reference for building cool asphalt pavement systems with using s-s PCMs. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to evaluate the impact of super-chilling on the quality of Atlantic salmon (Salmo salar) pre-rigor fillets. The fillets were kept for 45min in a super-chilling tunnel at −25°C with an air speed in the tunnel at 2.5m/s, to reach a fillet core temperature of −1.5°C, prior to ice storage in a cold room for 4 weeks. Super-chilling seemed to form intra- and extracellular ice crystals in the upper layer of the fillets and prevent myofibre contraction. Lysosome breakages followed by release of cathepsin B and L during storage and myofibre–myofibre detachments were accelerated in the super-chilled fillets. Super-chilling resulted in higher liquid leakage and increased myofibre breakages in the fillets, while texture values of fillets measured instrumentally were not affected by super-chilling one week after treatment. Optimisation of the super-chilling technique is needed to avoid the formation of ice crystals, which may cause irreversible destruction of the myofibres, in order to obtain high quality products. [Copyright &y& Elsevier]

Abstract: Farmed Atlantic cod (Gadus morhua L) were subjected to computerised X-ray tomography (CT) to evaluate CT as a non-destructive and rapid method for analysing muscle dry matter percentage (DM%) and liquid leakage in cod fillets. The study consisted of a total of 317 Atlantic cod (three batches) with gutted weights varying from 0.7 to 2.7 kg. The fish were scanned at four anatomical defined positions in the longitudinal direction. DM% in whole fillets correlated positively with average CT values over all scan positions, demonstrating that CT can be used as a non-destructive method to predict dry matter percentage in cod (r =0.6 to 0.9; SEP=0.3 to 0.7 DM%). The scan position anterior to the hind back fin gave highest prediction accuracy (r =0.63 to 0.93), and DM% in whole fillets provided better information than DM% analysed in specific anatomic positions. CT value and DM% increased from head to tail in all three batches (P <0.001), demonstrating that the CT-method can provide information also about the variation of DM% within fillets. Classification of liquid leakage during storage into low (<6%), medium (6–10%) and high (>10%) amounts also corresponded significantly with distinct CT (HU) intervals, demonstrating the potential for studying and improving liquid holding capacity in cod fillets using CT. Significant differences were detected in CT and DM% between sexes and between families (P <0.001) indicating genetic variation in these traits and a potential for improvement by selective breeding. [Copyright &y& Elsevier]