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Conventional Al-air battery has many disadvantages for miniwatt applications, such as the complex water management, bulky electrolyte storage and potential leakage hazard. Moreover, the self-corrosion of Al anode continues even when the electrolyte flow is stopped, leading to great Al waste. To tackle these issues, an innovative cotton-based aluminum-air battery is developed in this study. Instead of flowing alkaline solution, cotton substrate pre-deposited with solid alkaline is used, together with a small water reservoir to continuously wet the cotton and dissolve the alkaline in-situ. In this manner, the battery can be mechanically recharged by replacing the cotton substrate and refilling the water reservoir, while the thick aluminum anode can be reused for tens of times until complete consumption. The cotton substrate shows excellent ability for the storage and transportation of alkaline electrolyte, leading to a high peak power density of 73 mW cm−2 and a high specific energy of 930 mW h g−1. Moreover, the battery discharge capacity is found to be linear to the loading of pre-deposited alkaline, so that it can be precisely controlled according to the mission profile to avoid Al waste. Finally, a two-cell battery pack with common water reservoir is developed, which can provide a voltage of 2.7 V and a power output of 223.8 mW. With further scaling-up and stacking, this cotton-based Al-air battery system with low cost and high energy density is very promising for recharging miniwatt electronics in the outdoor environment.

In contemporary power plants, poor air temperature is one of the primary causes of rising unit temperatures and deteriorating boiler performance. The primary issue with an air preheater is air leakage on the gas flue side, which results in poor thermal performance. The high ash content of Indian coal exacerbates the issues with air tube heating. Air preheaters re developed to fulfill operational needs while taking into account the most important factors. Heat transmission, leakage, and pressure reduction are all factors to consider. The performance of the air-conditioning heater is being evaluated in this study using the Fluent 14.0 analytical tool from Computational Fluid Dynamics (CFD).

Battery power has been a popular choice of delivering DC power to many portable RF systems including wireless sensor nodes/internet of Everything (IoE). An autonomously powered RF system of the orders of 100’s of µwatts is becoming increasingly popular in recent times because of integrated solutions in energy harvesting. The minimum sensitivity of an RF energy harvester and the targeted deliverable output voltage for a specific load resistance are dictated by threshold voltage of transistors used and reverse leakage of such transistors. A detailed look into the architectures of rectifiers can help tackle design problems in the RF-DC conversion process. So in this work we focused on the design of integrated RF energy harvesting by studying four important architectures of RF-DC converters. To achieve a fair comparison between these architectures, a matching network operating at 0.8 MHz is designed and applied for simulation. All of these converters are tested in LT-SPICE XVII using the same designed matching network and the rectifiers are implemented in 180 nm CMOS technology.

Experimental investigation has been performed to study the leakage and wear characteristics of carbon seal working at high circumferential speed. To expand the scope of application, two newly designed carbon seals were compared: #1 Carbon Seal (CS1) with the inner diameter of 136 mm and including 4 segments, #2 Carbon Seal (CS2) with the inner diameter of 212 mm and including 6 segments. Air leakage tests were firstly conducted in the Medium-speed Seal Test Rig. The pressure ratio changed from 1.04 to 2.02 with the rotating speed varying from 0 to 18300 r/min. Of paramount concern was the durability test, including 300 h running time accumulated by three different working conditions, which was separately implemented on each carbon seal. The morphology variation of the friction surface, wear and leakage were recorded. Results indicated that the leakage monotonously increases with the pressure ratio and decreases with the rotating speed. Comparing with CS1, more typical features exist on the friction surface of CS2, which are generated by more severe wear. Continually, leakage characteristics deteriorate. Furthermore, fitted formula has been educed for the life prediction of carbon seal, which could provide some supports for aero-engine design.

Enhancing damping characteristic is one of the effective methods to solve the instability problem of the rotor system. The three-dimensional numerical analysis model of scallop damper seal was established, and the effects of inlet pressures, preswirl ratios, rotational speeds, interlaced angles and seal cavity depths on the rotordynamic characteristics of scallop damper seal were studied based on dynamic mesh method and multi-frequencies elliptic whirling model. Results show that the direct stiffness of the scallop damper seal increases with decreasing inlet pressure and increasing rotational speed and cavity depth. When the seal cavity is interlaced by a certain angle, which shows positive direct stiffness. The effective damping of the scallop damper seal increases with the increasing inlet pressure, the decreasing preswirl ratio and the rotational speed and cavity depth. There exists an optimal interlaced angle to maximize the effective damping and the system stability. The leakage of the scallop damper seal is significantly reduced with decreasing inlet pressure. The preswirl will reduce the leakage flowrate, and the rotational speed has a slight effect on the leakage performance. The leakage of the scallop damper seal decreases with increasing seal cavity depth.

With the continuous development of deep oil and gas, minerals, geothermal resources, and other resources, there are increasingly more stringent requirements for equipment. In particular, the ultra-high-pressure dynamic seals of deep mining device need to be developed. Therefore, considering the use of dynamic seals in unique deep mining environments, an ultra-high-pressure rotating combined dynamic seal was designed and developed and its sealing performance was experimentally measured and analyzed. The results show that the experimental device can operate stably under a pressure of up to 150 MPa and a rotating speed of 76 r/min, and can also operate normally under a rotating speed of up to 140 r/min and a sealing pressure of 120 MPa. During the operation of the ultra-high-pressure rotating combined dynamic seal, the sealing ring does not show obvious damage, which vouches for its sealing performance. No leakage of flow and pressure was detected in the all seal structures within the sealing pressure range of 0∼150 MPa. Therefore, the dynamic sealing performance of the device is intact under ultra-high-pressure conditions and can be applied in deep mining environments at a certain depth. The research and development of this device can aid future deep energy exploration and exploitation.

Various structural defects deteriorate tunnel operation status and threaten public safety. Current tunnel inspection methods face problems of low efficiency, high equipment expense, and difficult data management. Combining the deep learning model and the 3D reconstruction method based on structure from motion (SfM), this paper proposes a novel SfM-Deep learning method for tunnel inspection. The high-quality 3D tunnel model is constructed by using images taken every 1 m along the longitudinal direction. The instance segmentation of leakage in longitudinal images is realized using the mask region-based convolutional neural network deep learning model. The SfM-Deep learning method projects the texture of the images after defect recognition to the 3D model and realizes the visualization of leakage defects. By projecting the model to the design cylindrical surface and expanding it, the tunnel leakage area is quantified. Through its practical application in a Shanghai metro shield tunnel, the reliability of the proposed method was verified. The novel SfM-Deep learning method can help engineers efficiently carry out intelligent tunnel detection.

The electro-hydrostatic actuator (EHA) used in more electric aircraft (MEA) has been extensively studied due to its advantages of high reliability and high integration. However, this high integration results in a small heat dissipation area, leading to high-temperature problems. Generally, to reduce the temperature, a wet cooling method of using the pump leakage oil to cool the motor is adopted, which can also increase the difficulty of accurately predicting the system temperature in the early design stage. To solve this problem, a dynamic coupling thermal model of a wet EHA is proposed in this paper. In particular, the leakage oil of the pump is used as a coupling item between the electrical system and the hydraulic system. Then, an improved T-equivalent block model is proposed to address the uneven distribution of axial oil temperature inside the motor, and the control node method is applied to hydraulic system thermal modeling. Meanwhile, a dynamic coupling thermal model is developed that enables a dynamic evaluation of the wet EHA temperature. Then, experimental prototypes of wet motor and wet EHA are developed, while the temperature response of the wet motor at different rotation speeds and different loads and the temperature response of the wet EHA at no-load condition were verified experimentally at room temperature, respectively. The maximum temperature difference between the experimental and theoretical results of the wet motor as well as the experimental and theoretical results of the wet EHA is less than 8 °C. These test results indicate that the dynamic coupling thermal model is valid and demonstrate that the thermal coupling modeling method proposed in this paper can provide a basis for the detailed thermal design of EHA.

As an extreme manifestation of environmental degradation, karst rock desertification is caused by soil loss and rock exposure. In some areas with serious rocky desertification, there is no soil to be eroded or leaked. The soil loss in these areas superimposes soil erosion and unique subsurface loss by soil leakage through fissures, pipelines, sinkholes, etc., which directly reduce soil resources and accelerate rocky desertification. However, the factors driving soil erosion and subsurface loss by soil leakage are still unclear. Rainfall experiments were conducted on simulated slopes with surface-exposed bedrock and subsurface fissures based on field investigations in a karst rocky desertification area of Guizhou Province, China. Four factors, including rainfall intensity, slope gradient, bedrock exposure rate and subsurface fissure degree, were considered in the experiment. We found that the amount of soil surface erosion and subsurface leakage loss is driven not only by the runoff volume but also by other influential factors. Rainfall intensity is the driving factor determining the amount of surface erosion and subsurface leakage loss of soil and water and the relationship between them. The slope gradient plays a leading role only in subsurface fissure flow leakage loss. The bedrock exposure rate drives the surface soil erosion rate, shows a critical value (30%), and dominates the fissure flow leakage loss rate. Subsurface fissure density plays an important role in the surface loss of soil and water; however, an increase in the subsurface fissure density does not obviously accelerate the subsurface leakage loss of soil and water. Although this result, obtained from laboratory simulations, may differ at the field scale or larger, it could provide a foundation for systematic studies on soil erosion/leakage and insights into the relations between rocky desertification and soil erosion/leakage and their driving factors in karst rocky desertification.

Running applications on a rooting device makes the application vulnerable to data leakage. Therefore, many applications that require a high level of security are not allowed to run on rooted device. Common technique of detecting rooted device is by using Android API to discover rooting trace. However, the detection can be bypassed using Java function hooking script by the people who want to run the app on rooted device. This research will give illustration that the bypassing process becomes more easy with automation tool and hybrid analysis. In order to create the script, we use combination of static and dynamic analysis with three phases with specific function. Phase 1 aims to detect the estimated Java method that detect rooting, phase 2 will analyze that method on an unrooted device, then phase 3 will create the bypassing script based on the previous result. We also use automation tool to speed up the static analysis. We create two types of script: one that can be used on general application, and the other one that only can be used on specific app. Those types implement different scope: one with the certain Java method, and the other one with specific parameter or return value. In the end, we find that bypassing rooting detection is not complicated if the app use Java function to detect the rooted device. To complicate bypassing process, we encourage the developers to implement more advanced detection rooting technique.

Flexible quasi-solid zinc-ion batteries (ZIBs) have large potential in power applications due to the low price, wearable nature, safety, and high capacity. However, the use of transition metal sulfide cathodes in ZIBs has not been studied extensively and the underlying mechanism and theoretical basis of this type of batteries are not well understood. Herein, a highly active cobalt-doped Ni3S2 porous nanocone framework (C12NS) is designed and demonstrated as a zinc-ion battery electrode. First-principles calculation and experiments reveal that the cobalt dopant improves the battery properties greatly. The assembled flexible zinc-ion battery exhibits a high specific capacity of 453.3 mAh g−1 at a current density of 0.4 A g−1 in as well as excellent cycling stability as manifested by a capacity retention ratio of 89.5% at a current density of 4 A g−1 after 5000 cycles. The peak energy density of 553.9 Wh kg−1 is also superior to those of most recently reported NiCo-based zinc-ion batteries. More importantly, the flexible battery can be operated under severe mechanical bending and even continues to work after physical puncturing without showing leakage. These exciting results not only reveal a novel design of cathode materials for zinc-based batteries, but also suggest their immense commercial potential in portable and wearable electronics.

A real-time and molecule-level monitoring of the interfacial dynamic interactions between molecules and a cell membrane is of vital importance. Herein, taking TAT, one of the most representative cell penetrating peptides, as an example, a photo-voltage transient technique and a dynamic giant bistratal vesicle (GBV) leakage method were combined with the traditional giant unilamellar vesicle (GUV) leakage assays, to provide a molecule-level understanding of the dynamic membrane interaction process performed in a low ionic strength and neutral pH condition. The photo-voltage test based on supported phospholipid bilayers showed a quick disturbance (1 min) followed by a continuous reconstruction of the membrane by peptides, leading to a slight destruction (at TAT concentrations lower than 1 μg mL

Gate valve is mainly used to turn on or turn off the pipeline in pneumatic conveying. When the gate valve is fully open, the particles are easy to collide with the cavity rear wall and enter into the cavity, resulting in particles’ accumulation in the cavity. The particles in cavity will accumulate between the cavity bottom and the flashboard bottom wall and prevent the gate from turning off normally. Meanwhile, the particles’ collision with cavity rear wall will cause serious erosion. Both the particles’ accumulation and erosion will cause the poor sealing of the gate valve, further resulting in the leakage of the pipeline system. To reduce the particles’ accumulation in cavity and erosion on cavity when the gate valve is fully open, we simplify the gate valve into a cavity structure and study it. We find that adding a slope upstream the cavity can effectively reduce the particles’ accumulation in the cavity and the erosion on the cavity rear wall. In this work, Eulerian–Lagrangian method in commercial code (FLUENT) was used to study the gas–solid two-phase flow and erosion characteristics of a cavity with a slope. The particle distribution shows that the particles with Stokes number St = 1.3 and St = 13 cannot enter the cavity due to the slope, but the particles with St = 0.13 enter the cavity following the gas. For St = 13, the particles collide with the wall many times in the ideal cavity. Erosion results show that the slope can transfer the erosion on cavity rear wall to the slope and reduce the maximum erosion rate of the wall near the cavity to some degrees.

Dielectric polymer composites with conducting fillers would have great potential for diverse applications if their severe leakage loss could be addressed. In this regard, ternary composites using both ceramic and conducting materials as fillers might be an enabler for high dielectric constant and low dielectric loss. Herein, ternary composites with both Ti3C2Tx MXene conducting nanosheets and CaCu3Ti4O12 (CCTO) dielectric particles embedded in silicone rubber were studied. It was found that a ternary composite with 1.2 wt% (0.40 vol%) Ti3C2Tx MXene and 12 wt% (2.58 vol%) CCTO could provide an overall superior performance that include a high dielectric constant of 8.8, low dielectric loss of less than 0.0015, good thermal stability up to 450 °C, and excellent mechanical properties with tensile strength of 569 kPa, elastic module of 523 kPa and elongation at break of 333%. The outstanding performance is attributed to the improved uniform dispersion and good interfacial compatibility of mixed fillers in the polymer matrix, suggesting ternary composites might be a better option over their binary counterparts in preparing high performance dielectric composites.

Despite of the hazardous risk of Pb2+ leakage, lead dioxide has been attributed as a quasi-ideal anode material with high oxygen evolution potential, excellent conductivity, good stability and low cost in electrochemical oxidation wastewater treatment technique. In this study, a novel Ti/PbO2 anode was fabricated by embedding raw materials that are readily and cheaply available, i.e., hairs. The structure-activity relationship of the new electrode was firstly revealed by material and electrochemical characterizations. Then different levels of pollutants (azo dye, phenol and maleic acid) were used to investigate the electrochemical oxidation performance of the new electrode. Finally, the accelerated electrode lifetime and Pb2+ leakage tests were carried out. Results showed that the embedded hairs changed the preferential crystallographic orientation of PbO2 and decreased the grain size. Hairs introduced additional roughness and active sites, and decreased the electrode impedance, especially under 5 mg/cm2 of embedding amount. The removal efficiencies of different target pollutants were enhanced more or less by embedding appropriate amount of hairs, depending on the current density, but loading excessive hairs had a negative effect. The accumulation of intermediate products during phenol degradation was also changed by the hairs. The new electrode could undergo ∼550 h of harsh electrolysis. It is also relieved that the Pb2+ leakage was found to be suppressed during this long-term electrolysis process.

The hydrogen pressure inside tanks and its adjacent pipes can reach up to 70 MPa in fuel cell vehicles. This is the weak links of hydrogen leakage. The diagnosis time of mainstream hydrogen leakage diagnosis method based on hydrogen concentration sensors (HCSs) is easily affected by the number and location of installed sensors. In this study, a data-driven diagnosis method is proposed for the high-pressure hydrogen leakage. Fisher discrimination analysis and linear least squares fitting are used for data preprocessing, relevance vector machine is used for pattern recognition. When the total volume of tanks is 82 L and the hydrogen leakage flow rate is larger than 2 g/s, the diagnosis accuracy of the proposed method is higher than 95% and the diagnosis time is constant. When the leakage location is far away from HCSs, the proposed method can the diagnose hydrogen leakage in a shorter time than mainstream method.

Directional solidification of Ti–46Al–8Nb (at.%) intermetallic in the Y2O3 doped BaZrO3/Al2O3 composite ceramic mould was carried out using Bridgman apparatus. To increase the success rate of Ti–46Al–8Nb single crystals preparation and improve the quality of the ingots, the failure mechanism of the mould in directional solidification experiments was evaluated. Nucleation and propagation of cracks in the moulds were investigated by tracing each key process of the experiment, the effect of pores in the mould on the target alloy was revealed by studying the mould/metal interface. The results show that the macrocracks in the facecoat of the mould would lead to the leakage of the alloy melt. Furthermore, the alloy melt would infiltrate into the mould through large-size pores, which would increase the oxygen content of the target alloy, and also form inclusions containing O, Zr, Si and Y elements in the alloy ingot.

This work reports the fabrication of AuNR@MSNs [i.e., gold nanorods (AuNRs) coated with mesoporous silica nanoshells (MSNs)] with independent sensitivities to pH and near-infrared (NIR) light for reversible on–off switching of drug release without premature drug leakage. The fabrication involves the incorporation of lauric acid (LA) as a thermosensitive gatekeeper, followed by the coating of tannic acid (TA) layers as a pH-sensitive gatekeeper. The protonation–deprotonation of the TA layers according to change in pH can result in their swelling–deswelling to induce pH-sensitive drug release, while the solid–liquid phase transition of LA by NIR light-induced heat generation in AuNRs enables the NIR light-controlled release of preloaded drug molecules. The interplay between these dual gatekeepers allows the release of pre-loaded drug from the AuNR@MSN-LA@TAs (i.e., AuNR@MSNs incorporating LA and TA) only at acidic conditions under NIR light irradiation, without premature drug leakage under inactive conditions (neutral pH or no NIR light). Moreover, the reversibility of the gatekeepers can make an on–off mannered drug release. Benefiting from the capability of the gatekeepers to induce pH-/temperature-sensitive release, along with the photothermal ability of AuNRs, the AuNR@MSN-LA@TAs can exhibit a satisfactory anticancer performance without undesired drug leakage.

Experiments are conducted to study leakage and piping through circular geomembrane holes from the overlying silty sand tailings. Three subgrades, a poorly graded gravel, a well-graded gravel, and a poorly graded sand are studied. Test results show that leakage through the geomembrane hole is not proportional to the surface area of the hole. A 5-fold increase in hole diameter from 10 to 50 mm results in an approximately 6-fold increase in leakage. With the filter incompatible subgrade, piping is prone to occur at small consolidation stress and/or with a larger hole. Open voids within soil skeleton induced by piping result in a 2- to 4.5-fold higher leakage than in the no-piping cases. The extent of silty sand piping and internal erosion depends on the filter compatibility and surface regularity of the subgrade, which could be significantly improved by increasing its fine particle component or placing a layer of nonwoven needle-punched geotextile beneath the geomembrane.

The European heat pump market is growing every year as European legislation moves towards the use of natural refrigerants that have less global warming potential than conventional refrigerants. Even though heat pumps are very efficient, the appearance of hard-to-detect faults increases energy consumption. The present study emulated some of the most common faults on a variable-speed heat pump charged with propane. The faults tested were evaporator fouling, compressor valve leakage, liquid line restriction and refrigerant overcharge. The effect of these faults on performance and several heat pump features are described. Evaporator fouling was the fault with least COP degradation and compressor valve leakage with the most (7% and 56% COP reduction, respectively). The results are compared with the results from a comparable study. The heat pump covered the demand generated by nearly all the faults at the expense of increasing the power consumption. The features of each fault are summarized in a chart, which could be used as table for diagnosing faults.

While MOSFET miniaturization continues to face increased challenges related to process variations, supply voltage scaling and leakage currents, exploratory devices such as Graphene Nanoribbon Field Effect Transistors (GNRFET), Tunnel Field Effect Transistor (TFET), and Carbon Nanotube Field Effects Transistors (CNFET) could provide solutions for continued device scaling with better power/performance trade-offs. The GaN TFET used in this work is a heterojunction device, where the material properties of Ga and N result in a bandgap of 3.2eV and ultra-low IOFF current. Moreover, the properties of Ga and N result in a steep-switching device with a subthreshold swing of 30mV/decade. The structure of graphene material results in high conductivity of electrons, even at very high operating temperatures, making GNRFETs a high-performance device. However, graphene specific line-edge roughness can degrade performance, and thus process related variations can have a negative impact for GNRFETs. In CNFETs, the mobility and the velocity of the conducting carriers are functions of the carbon nanotube and the gate length. The length and the diameter of the carbon nanotube material adds parasitic capacitance and resistance to the model, contributing to slower speed of the device. In this paper, the impact on power, performance, and static noise margins (SNM) of the traditional single-port 6T-SRAM and modified single-port 8T-SRAMs designed using exploratory devices are analyzed with a set figure of merit (FOM), elucidating the material properties of the devices. The results obtained from this work show that GNRFET-based SRAM have very high performance with a worst-case memory access time of 27.7 ps for a 16x4-bit 4-word array while CNFET-based SRAM bitcell consume the lowest average power during read/write simulations at 3.84 µW, while TFET- based SRAM bitcell show the best overall average and static power consumption at 4.79 µW and 57.8 pW. A comparison of these exploratory devices with FinFET and planar CMOS showed that FinFET-based SRAM bitcell consumed the lowest static power at 39.8 pW and CMOS-based SRAM had the best read, write, and hold SNMs of 201 mV, 438 mV and 413 mV respectively.

Leakage is always a concern in the interface between the cylinder block and the head. Nowadays, sealing of this interface is almost exclusively achieved by multi-layer steel head gaskets. However, it is not only the gasket's quality that is responsible for perfect sealing. An equally important role is played by the surface topography of the mating surfaces. The top surface of the cylinder block and the bottom surface of the cylinder head are machined by face-milling and present periodic tool marks features. Based on the surface topography measured by high definition metrology, this paper presents a novel sealing analysis method to evaluate the sealing performance of the critical topography region around the combustion chambers. The method consists of three modules: tool paths or channels reconstruction, sealing region segmentation based on channels' directions, and sealing analysis on sealing regions with different channel directions. An engineering case demonstrates the sealing analysis procedures and verifies the effectiveness of the sealing analysis method. The analysis of 12 ring-shaped sealing regions found that channels' directions do have a significant impact on surfaces' sealing properties. Circumferential channels or paths are advantageous for surface sealing, while radial channels are prone to leakage.

This work addresses the issues of long-term leakage rate prediction, which is crucial for durability study of proton exchange membrane fuel cells (PEMFCs). A theoretical model is presented for the leakage rate of compressive seal structures in PEMFCs, based on the combination of three numerical techniques, namely Lattice-Boltzmann method (LBM) simulations for rough wall interfacial gaps, a numerical 3D rough-surface generation technique, and Finite-Element-Analysis (FEA) for micro-contact mechanics of single asperity. The model clearly reveals the quantitative influence of various factors on the leakage rate without any empirical regression coefficients, and therefore can be easily integrated with structural mechanics and aging mechanism analyses. Long term sealing performance comparisons with three types of rubber material identify liquid silicone rubber to have the optimal durability. When influences of water environment are taken into account, an accelerated degradation of sealing performance can be observed after approximately 3000 h of operation. In addition, the effect of stress loss on leakage rate can be effectively suppressed by reducing surface roughness, reducing gasket thickness and increasing strain level. The proposed theoretical model provides an effective approach for the design of metal-bipolar-plate PEMFCs seal structures.

The motion trajectory of hydrogen leakage is an essential safe issue for the application of hydrogen energy. A dimensionless fast-running motion trajectory prediction model is proposed to predict the dispersion characteristics of the buoyant jet of hydrogen leakage for the accident. The impact of different leakage angles, leakage velocity and thermal stratification of ambient air on hydrogen leakage behavior was analyzed. The new developed model was verified by experimental results in literatures. Leakage hydrogen can flow upwards freely in a uniform environment. However, it shows an oscillating trajectory at a certain height in a thermally stratified environment, which is so called “locking phenomenon”. The trajectory of hydrogen leakage is upward and hydrogen gathers at the top of the space to form stratification in a uniform environment, while the hydrogen leakage shows an oscillating trajectory at a certain height in a thermal stratification environment. With the increase of Froude number Fr, it shows that the stable height and maximum height of the leakage airflow have a trend of rising first and then falling in a thermally stratified environment. The findings are expected to give guidance in real-world situations, for example, a larger Fr value and a larger temperature gradient can lead to a decrease in the stable height in the thermally stratified environment. It is found that the fitting of the stable height with different temperature gradients satisfies the power function relationship. This work is expected to be helpful for reducing hydrogen leakage accumulation and explosion risk.

An ancient B.T.M. with P.C.M. was controlled through the issues of high inflexibility of phase change material, leakage problems and very low conductivity in thermal energy. This research paper reports a facile batter thermal management and creativity along with induced non-rigid phase change material composites. This battery model can be determined by the flexible phase change material composites along with an intervention due to the recovery in shape and non-rigidity of flexible phase change components. This assemble was modelled to be efficient and compact without any requirement for grease. A constant state reveals various stages of phase change material which has various properties in thermal efficiency. A unified state was linked with the recovery shape of flexible phase change components, which can cause a low resistance in FCPCM and battery. Battery thermal management demonstrates the perfect process of thermal control power. If the battery was discharged from 90 to 10% of charge, then the temperature of flexible phase change components depends upon battery thermal management. It was 44.5 °C during the 3.5 °C rate, which was 29.8 °C lower than no phase change material. It also reveals low-temperature oscillation inside the long-time process and range of heat of recovered phase change material. The performance of battery thermal management and its flexibility will give perceptions of passive battery thermal management systems.

Linear compressor has received continuous attention owing to its high energy conversion efficiency and oil-free operation. The dynamic behavior of a linear compressor is critical to understand its operation mechanism. However, the dynamic behavior of linear compressor cannot be fully visible. In response to this issue, a real-time measurement system is established to analyze the dynamic behavior of linear motor, piston and valve movements and the cylinder pressure. And deprived effects of gas force, i.e., piston offset and leakage are also discussed. The results show that current/displacement curves generate distortion on account of the nonlinear characteristic of gas force. Distortion of current curves (THD is up to 73.69% at 60Hz) is more obvious due to the minor inductance. The valve appears delay opening, flutter, additional displacement fluctuation and delay closing compared with ideal valve. A high spring stiffness of valve makes slight difference to piston offset. The expansion/compression index in the p-V diagram with a high frequency has apparent increase owing to the variations of duration of heat exchange. The piston offset is nearly constant with the increasing of strokes while piston offset increases with the increment of discharge pressure/frequency. The leakage loss proportion with evaporation temperature at 5°C and condensation temperature at 30∼40°C does not exceed 6%.

Summary As an emerging energy-harvesting technology, enhancing the output performance of triboelectric nanogenerators (TENGs) is crucial for its practical application. Here, a dielectric enhancement effect is firstly proposed to improve the output performance of TENGs. It is found that the dielectric enhancement layer greatly elevates the triboelectrification effect, and the enhanced performance is verified by all types of TENGs. Thus, the output power of alternative current TENG (AC-TENG) and direct current TENG (DC-TENG) realizes 8.5-fold and 2.6-fold enhancement of normal devices, respectively. Besides this, the dielectric enhancement layer with leakage performance is proven to be necessary for DC-TENG to produce a continuous output. Our work provides a simple and universal strategy for elevating the performance of all types of TENGs, which is beneficial to the promotion of large-scale energy harvesting by TENGs.

This research focuses on reactive hydrogen leakage due to the fracturing of high-pressure hydrogen tanks to develop a coupled computing method that can simultaneously perform reactive fluid-structure interaction analyses. The integrated computational approach to reactive hydrogen leakage with combustion due to wall crack propagation was implemented using a hybrid of the coupled particle and Eulerian methods. This computational method provides valuable safety information for predicting crack propagation and hydrogen leakage with combustion reaction in pressure tanks as an essential part of assessing hydrogen as an energy vector. As a result, the effect of crack formation and wall boundary conditions on hydrogen turbulent diffusion and concentration distribution and the thermodynamic behavior of the chemical reaction were predicted computationally. It was found that a combustion reaction does not occur near the streamwise axis at the duct center because there is an excess of hydrogen fuel, which increases scalar dissipation, and that the combustion reaction separated into upper and lower regions as it proceeded.

This paper mainly studies the synchronization issue of quaternion-valued fuzzy cellular neural networks (QVFCNNs) with leakage delays. To avoid non-commutativity, we decompose the QVFCNNs into an analogous real-valued system. Then, we investigate the existence of almost periodic solutions based on the Banach fixed point theorem. Also, a novel state-feedback controller is designed to guarantee the synchronization of the global exponential almost periodicity. Finally, two examples are given to illustrate the effectiveness of our results.

Piston rod packing, a critical part of compressor provides dynamic sealing surrounding the piston rod. Typically, casings with one or more rings in each, are bolted to the cylinder head using the flange for providing effective sealing. During operation the packing rings are subjected to cyclic loads under high pressure and high-speed operating conditions. The pressure to which packing rings are subjected is usually as high as the pressure in compressor chamber. Failure of the packing to operate satisfactorily can result in plant downtime which eventually may affect the output. Hence, packing rings need to be critically designed. In this paper an attempt is made to develop a mathematical model of various forces and pressures acting on packing ring with respect to crank angle. The paper also illustrates the approach for calculation of axial and radial thickness. Distorted profile predicted using the given Fourier series can be used to calculate the leakage area. Compressor reliability and cost-effectiveness can be effectively predicted using the developed model.

To overcome the leakage of phase change materials (PCMs) above melting temperature, PCMs are commonly encapsuled by chemically crosslinked networks, which bring the issues of reparability, reprocess-ability and recyclability making for the environment pollution and resource waste. Herein, a reversible aromatic disulfide is adopted to form dynamic epoxy networks which not only encapsulate polyethylene glycol (PEG) as the shape-stabilized PCMs (SSPCMs) but also address the issues about the un-recyclability of traditional SSPCMs. The PEG was well encapsulated and uniformly dispersed in disulfide-based epoxy due to the elaborate molecular design. The obtained SSPCMs (named EXAP2) shows typical solid–solid phase transitions characteristic and thermal reliability with high latent heat value of 82.7 J/g. Besides, the EXAP2 exhibit dynamic performance and can be reprocessed by hot press via the disulfide bonds exchange reaction above topology freezing temperature (Tv). And the reprocessed EXAP2 exhibits close phase change properties with the original sample, implying the reprocessing does not affect the crystalline structure and encapsuling capability of disulfide crosslinked networks. This strategy prove a significant way for fabricating the novel SSPCM with recyclability, reprocessability and reliability.

Corrosion is regarded as one of great challenges for the application of salts-based phase change materials. To address such problem, a novel skeleton of modified diatomite-based porous ceramic was used to load NaNO3 salt and develop shape-stabilized NaNO3. Particularly, thermophysical properties of composites with skeletons of unmodified and modified diatomite-based porous ceramics (UM-DC and M-DC4) were analyzed. The results showed that these two skeletons effectively prevented NaNO3 from leakage and were chemically compatible with NaNO3. Shape-stabilization of NaNO3 using porous ceramic hardly changed phase transition temperature, but decreased latent heat and enhanced thermal stability. M-DC4 possessed a capacity to load 58.67 wt% salt, nearly 10 wt% higher than other porous ceramics. Compared with NaNO3/UM-DC, NaNO3/M-DC4 performed a higher thermal energy storage density and efficiency of 382.92 J/g and 58.71%, respectively, within 130–330 °C. Importantly, NaNO3/M-DC4 exhibited much better cycling stability during 500 thermal cycles, benefited by the improved micro-flow of molten salt in M-DC4; while NaNO3/UM-DC appeared crack after 100 thermal cycles. Accordingly, the novel skeleton could greatly enhance thermophysical properties of shape-stabilized NaNO3. Such composites could be easily integrated into solar thermal energy storage system. This work proposed a new strategy for the application of salts-based phase change materials.

Ionic liquids, as a kind of liquid conductors with the unique inherent abilities of rapid self-healing, highly adaptive deformation, reconstruction, as well as high ionic conductivity, have been highly praised and recommended as a new competitive conducting material for green electronics. However, ionic liquids are likely encountered with the leakage problems when they are integrated into electronic devices. This issue as well as the need to develop intelligent electronics stimulate the innovation of ionic liquids with response characters besides conducting performance. Some "innovative" or "functional" ionic liquids consisting dynamic chemical bonds can reversibly switch between different states in response to external stimuli. These specialized ionic liquids afford powerful supplements to minimize the issue of leakage of ionic liquid conductors from electrical circuits, and also exhibit the properties of self-healing, reprocessing, adaptive deformation, which accord with the forthcoming era of Internet of Things. This minireview systematically summarizes the progresses of ionic liquid-based conductors containing dynamic bonds, particularly highlighting their applicable merits in self-healing, stretchable, and recyclable aspects. We also discuss the challenges in the next period and describe an unambiguous future of this research area.

Experiments are conducted to quantify leakage through holes in a geomembrane (GMB) overlain by tailings with 30% fines and underlain by a well-graded gravel. Analytical and empirical equations for predicting leakage through a circular hole are used to analyze the data. Test results show that changing the hole shape from circular to noncircular increases the leakage. Leakage through 2000 mm2 triangular, diamond, and square holes are all 15% higher than the 2000 mm2 circular hole. An increase by up to 33% is observed for a rectangular hole. The analytical equations for predicting leakage and head loss through a hole given by the modified Rowe-Booker equation are experimentally verified. The spatial distribution of fines content within about five diameters of the hole is shown to have a notable impact on leakage. Up to a 100% increase in leakage is detected due to 3% reduction in the fines content around the hole. For homogeneous tailings, the ratio of head loss within the hole and above the hole to total head loss are independent of consolidation stress and water head and primarily depend on the hole geometry (i.e., shape and size). Finally, the combined effect of tailings thickness and water head on leakage is discussed.

Microencapsulating phase-change materials (PCMs) into CaCO3 shell is considered as an effective way to resolve the leakage problem of the microcapsule system and enhance its heat transfer. Herein, we designed and fabricated a type of phase-change microcapsule system based on an n-docosane core and CaCO3/Fe3O4 composite shell using a nonaqueous emulsion-templated self-assembly technology for enhancing solar photothermal energy absorption, conversion and storage performance. The type and addition amount of templating agent and the mass ratio of PCM core to wall material play key roles in the formation of microcapsules with a controllable spherical or rhombohedral morphology and a perfect core-shell microstructure. The resultant phase-change microcapsules show a satisfactory latent heat-storage capacity of around 140 J/g, high encapsulation ratio of over 59%, high thermal conductivity of 0.795 W m−1 K−1, excellent leakage prevention capability and good thermal cycle stability when synthesized under the optimum synthetic condition. More importantly, the phase-change microcapsules exhibit a significant enhancement in solar photothermal conversion and storage performance due to the presence of Fe3O4 nanoparticles in their shell, and their photothermal conversion efficiency was improved by 47.9% compared to the corresponding microcapsules without Fe3O4. In conclusion, the phase-change microcapsules developed in this work show considerable potential in high-efficient solar energy utilization.

Radial leakage was commonly regarded as the primary factor restricting the aero-thermodynamic performance of scroll compressors. In this paper, a passive flow control approach of micro-grooves in scroll wrap tip for the radial leakage in the scroll compressor was proposed, and its flow characteristics were numerically investigated. The impact of micro-grooves geometric parameters, such as groove number, depth, and partitions, on the flow control effect of the radial leakage was discussed, which was obtained by analyzing the evolution of the flow field and its influence on the performance of the scroll compressor. Results showed that the adoption of micro-grooves in scroll wrap tip yielded a significant limitation on the radial leakage, and geometrical parameters of the micro-grooves directly affected the flow control performance. Increasing groove numbers and partitions decreased the radial leakage effectively, while the leakage decreased first and then increased with the increase of the groove depth. The energy dissipation induced by the continuous throttling effect, jet expansion, and vortex in the groove cavity was the main flow control mechanism. The quadruple-grooves with the groove width of 0.5 mm and the groove depth of 100 μm were adopted in this study eventually. The volumetric and isentropic efficiency of the scroll compressor raised up 2.1 and 1.0 percentage point compared to the original case, respectively. Through reasonable working conditions and micro-grooves geometry, the aero-thermodynamic performance of the oil-free scroll compressor could be improved effectively by the scroll wrap tip with micro-grooves.

Phase change materials (PCMs) have garnered intensive attention due to their high energy density and stable energy output in the field of thermal energy storage. However, the low thermal conductivity (TC) and liquid phase leakage of PCMs during phase transition significantly prevent widespread applications. Recently, two-dimensional (2D) materials are being extensively applied in improving the performance of PCMs, relying on their ultrahigh TC and excellent loading capacity. Importantly, their superior optical and electrical properties can offer PCMs with multi-responsive thermal energy conversion ability. This review summarizes the latest developments, emerging trends and challenges of 2D materials for advanced PCMs. We proceed from the importance of thermal energy storage and the key roles of 2D materials in the performance improvement of PCMs. Then, the fundamentals related to energy storage and thermal conduction mechanism of PCMs is systematic discussed. Further, the major preparation strategies and the major applications of 2D materials-based PCMs are emphasized in the thermal management of lithium-ion battery, solar-thermal, solar-thermal-electric and electro-thermal conversion and storage. Finally, the challenges and emerging perspectives are envisaged for deepening the future study and extending the applications of 2D materials for high-performance PCMs.

The rapid development of next-generation flexible electronics stimulates the growing demand for flexible and wearable power sources with high energy density. Li metal capacitor (LMC), combining with a Li metal anode and an activated carbon cathode, exhibits extremely high energy density and high power density due to the unique energy storage mechanism, thus showing great potential for powering wearable electronic devices. Herein, a flexible LMC based on an in situ prepared PETEA-based gel polymer electrolyte (GPE) was reported for the first time. Owing to the high ionic conductivity of PETEA-based GPE (5.75 × 10−3 S/cm at 20 °C), the assembled flexible LMC delivers a high capacitance of 210 F/g at 0.1 A/g within the voltage range from 1.5 V to 4.3 V vs. Li/Li+, a high energy density of 474 Wh/kg at 0.1 A/g and a high power density of 29 kW/kg at 10 A/g. More importantly, PETEA-based GPE endows the LMC with excellent flexibility and safety, which could work normally under abuse tests, such as bending, nail penetration and cutting. The in situ prepared PETEA-based GPE simplifies the fabrication process, avoids the risk of leakage and inhibits the growth of Li dendrite, making LMC a promising flexible energy storage device for the flexible electronic field.

Phase change materials (PCMs) have been extensively characterized as promising energy materials for thermal energy storage and thermal management to address the mismatch between energy supply and demand in various energy systems. To overcome the long-standing drawbacks of PCMs, such as low thermal conductivity, liquid leakage, phase separation, and the supercooling problem, advanced form-stable phase change composites (PCCs), which are fabricated by chemical modifications or the incorporation of functional additives, are of great significance for overcoming these shortcomings and promoting the broad-scale application of PCMs. Herein, we comprehensively review the state-of-the-art and critical issues of PCCs with a special focus on the preparation, thermal performance, and applications of PCCs. The different preparation methods are summarized and classified as hybrid confinement, encapsulation and polymerization of PCMs. Moreover, the thermal performances of metal-, carbon-, and ceramic-based PCCs are analyzed and compared systematically. Furthermore, the versatile applications of PCCs for energy harvesting, thermal storage, and thermal management are also summarized. Finally, future outlooks and prospects associated with the development of PCCs for high energy density and power density are highlighted. This review provides comprehensive and in-depth insights into the progress of PCCs regarding material preparation, thermal performance, energy storage and thermal management.

In this paper we investigated the stability of fractional order fuzzy cellular neural networks with leakage delay and time varying delays. Based on Lyapunov theory and applying bounded techniques of fractional calculation, sufficient criterion are established to guarantee the stability. Hybrid feedback control is applied to derive the proposed results. Finally, numerical examples with simulation results are given to illustrate the effectiveness of the proposed method.

This paper reviews materials challenges and recent progress for selective area regrowth and doping for vertical gallium nitride (GaN) power devices. The purpose is to realize randomly placed, reliable, contactable, and generally useable laterally patterned p-n junctions, which are the building blocks for various advanced power rectifiers and transistors. The general regrowth process and regrowth dynamics in trenches were discussed, where the effects of trench geometries, growth methods, and bulk substrates were elucidated. Comprehensive materials characterization techniques were utilized to analyze the regrown structures, including scanning electron microscopy, transmission electron microscopy, atom probe tomography, scanning probe microscopy, and secondary-ion mass spectrometry. Cathodoluminescence and secondary electrons in scanning electron microscopy and atom probe tomography were used to achieve lateral and vertical dopant profiling at a sub-micron scale. The regrowth interface after dry etching accumulated a high density of impurities and charges, contributing to the formation of a p+-n+ tunneling junction. This hypothesis was further confirmed by the electrostatic potential profile at the regrowth interface using electron holography. Novel etching technologies were investigated to improve the regrowth interface. It was found that low-power dry etching significantly reduced the interfacial charges and the reverse leakage currents of regrown p-n junctions. Photoelectrochemical wet etching was found to be effective in reducing deep-level defects near the regrowth interface. Atomic layer etching uses self-limiting chemical processes, thus removing the damaged layers without inducing further etching damage. Tertiarybutylchloride-based in situ etching may serve as an alternative etching method to dry etching with reduced etching damage. In terms of devices, regrown p-n junctions with low leakage currents and vertical junction field-effect transistors were demonstrated. Further improvements in selective area regrowth and associated devices can be expected using regrowth optimization and regrowth interface engineering via surface treatments and low-damage etching. These results represent an important step towards realizing selective area regrowth and doping for high performance GaN power electronics devices and systems.

In this paper, the influence of paraffin/expanded vermiculite-diatomite form stable composite phase change materials (paraffin/EVC-D FSCPCM) on the strength and thermal properties of the mortar was studied through experiments and numerical simulations. The mechanical properties, thermal conductivity and thermoregulation performance of the paraffin/EVC-D FSCPCM integrated mortar were studied in detail. Meanwhile, the energy-saving effect of the paraffin/EVC-D FSCPCM integrated mortar in building was studied by numerical simulation. Thermal-cycling test results indicated a 10.9% leakage reduction of form stable composite phase change material with a diatomite coating. Strength test results showed the addition of diatomite increased the compressive strength of paraffin/EVC-D FSCPCM integrated mortar. The thermoregulation performance test showed the paraffin/EVC-D FSCPCM integrated mortar displayed good thermoregulation performance regardless of the testing conditions (lab-scale or actual environment). During laboratory-scale thermal regulation performance testing, when the volume replacement rate of paraffin/EVC-D FSCPCM to sand reaches 70%, the paraffin/EVC-D FSCPCM integrated mortar reduced the maximum temperature of the testing room by 3.1 °C; in an actual environment, it reduced the maximum temperature of the wall board by 2.68 °C. The simulation results showed that in summer, compared with cement mortar, the use of paraffin/EVC-D FSCPCM integrated mortar in the building could save 17.03% of energy consumption.

In rotary compressors, adding one cylinder to the conventional two in the axial direction without increasing the flow rate and load per cylinder can be expected to be an effective means for further increasing the capacity without deteriorating efficiency and reliability. This paper presents the prototype design with three different specifications for a three-cylinder rotary compressor, their performance measurement results, and their efficiency analysis. To investigate a bending deformation of the crankshaft, we have performed an axis behavior analysis as the elastic body and used the results for the efficiency analysis. Our efficiency analysis finds that the three-cylinder rotary compressor requires a middle bearing between the cylinders to reduce leakage in the compression chamber. The three-cylinder prototype demonstrates a higher COP than two-unit operation of the two-cylinder conventional models in almost the entire refrigeration capacity range and a great advantage in the medium capacity range especially.

High dielectric response and low leakage conduction are desired in polymer/ceramic composite dielectrics for capacitive energy storage. Rational structural design of hybrid ceramic filler can lead to a balance between high dielectric constant and insulation in composites. In this study, high dielectric constant and breakdown strength were achieved in fluoropolymer/mesoporous silica@CdTe nanocomposite films. Mesoporous silica nanoparticles (MSNs) were employed owing to their high insulation and complex electron-leakage channel. CdTe quantum dots combined with pore-canal inwalls of MSNs were employed because of their internal exciton polarization and MSNs/CdTe interface polarization. Compared with polymer/MSNs composites, polymer/MSNs@CdTe composites exhibited remarkably improved dielectric constant, slightly increased dielectric loss, and slightly reduced breakdown strength. High dielectric constant of ternary composites was ascribed to exciton orientation inside CdTe and interfacial dipole orientation between MSNs and CdTe. High breakdown strength was attributed to high insulation in MSNs and long-range electron transfer inside MSNs@CdTe. An optimal ternary composite with 12 wt% MSNs@CdTe showed a high dielectric constant of ~56, low dielectric loss of ~0.19 at 100 Hz, and high breakdown strength of ~308 MV m-1. The results of this study can provide insights for enabling large-scale fabrication of modern composite dielectrics based on mesoporous particles@semi-conductive quantum dots fillers.

High-quality ferroelectric films of Mn-doped Pb(Zr0.3Ti0.7)O3 (PMZT) were prepared using the sol-gel method, and the temperature dependence of ferroelectric, dielectric, and leakage current properties (J–E) were explored in detail using the top electrode/ferroelectric films/bottom electrode capacitor heterostructure. The enhancement of polarization and dielectric properties by element doping is clearly observed by 3% Mn-doping. Such enhancement is beneficial for the application of these films in ferroelectric random-access memory. In addition, the analysis of leakage current reveals symmetric behavior with 3% Mn-doping and the leakage current density gradually increases with increasing temperature, which may be due to the movement of domain wall and oxygen vacancy. The dominant leakage current conduction mechanism is bulk-limited ohmic or interface-limited Schottky emission conduction within a wide temperature range. The results might be meaningful for further work on ferroelectric electrical devices with improved ferroelectric and dielectric properties.

Metal–organic framework (MOF) membranes hold great promise in energy-efficient chemical separations. The outstanding challenges of the microstructural design stem from (1) thinning of membranes to immensely reduce the mass-transfer resistance (for high permeances); (2) tuning of orientation to optimize the selective transport of gas molecules, and (3) reinforcement of intercrystalline structure to subside leakage through defective gaps (for high selectivity). Here, we propose the ZIF-L membrane that is completely confined into the voids of the alumina support through an interfacial assembly process, producing an appealing membrane-interlocked-support (MIS) composite architecture that meets the requirements of the microstructural design of MOF membranes. Consequently, the membranes show average H2 permeances of above 4000 GPU and H2/CO2 separation factor (SF) of above 200, representing record-high separation performances of ZIF-L membranes and falling into the industrial target zone (H2 permeance > 1000 GPU and H2/CO2 SF > 60). Furthermore, the ZIF-L membrane possessing the MIS composite architecture that is established with alumina particles as scaffolds shows mechanical stability, scraped repeatedly by a piece of silicon rubber causing no selectivity loss.

The development and application of hydrogen energy in power generation, automobiles, and energy storage industries are expected to effectively solve the problems of energy waste and pollution. However, because of the inherent characteristics of hydrogen, it is difficult to maintain high safety during production, transportation, storage, and utilization. Therefore, to ensure the safe and reliable utilization of hydrogen, its characteristics relevant to leakage and diffusion, ignition, and explosion must be analyzed. Through an analysis of literature, in combination with our practical survey analysis, this paper reviews the key issues concerning hydrogen safety, including hydrogen incident investigation, hydrogen leakage and diffusion, hydrogen ignition, and explosion.

The present paper is focused on development of the thermodynamic model and a heat-driven Vuilleumier refrigerator. Thermodynamic properties and performance are predicted by thermodynamic model. On the other hand, a prototype Vuilleumier refrigerator with crank drive mechanism is built and the performance is measured. In the thermodynamic model, the refrigerator is divided into five working spaces for analysis, including hot chamber, hot regeneration chamber, middle chamber, cold regeneration chamber and cold chamber. Also, the influence of clearance leakage between middle chamber and buffer chamber is investigated. The effects of geometrical parameters, charged pressure, rotating speed, heating temperature, cooling temperature and heat loading on the cold head temperature are evaluated. In addition, the numerical results and the experimental data under different operating parameters are compared for model validation. As the Vuilleumier refrigerator operated at 22 bar pressure, 600 rpm rotating speed, 900 K heating temperature and 276 K cooling temperature, the cold head can reach a zero-load temperature of 221 K. When a 0.7 W heating load is applied on the cold head, cold head temperature of 252.6 K and coefficient of performance of 0.0068 can be obtained.

CO2 shipping is a viable transport alternative when pipelines are impractical. Lack of experience in large-scale CO2 shipping projects implies uncertainty in selecting optimal cargo conditions and operational safety procedures. The risk of uncontrolled release of CO2 arises in case of mechanical failure of storage or cargo vessels, and a thorough understanding of the discharge phenomena, including the propensity for solid formation, is necessary to develop safety protocols. A refrigerated experimental setup is established in this study to investigate the release phenomena of liquid CO2 under shipping conditions. The rig features a dome-ended cylindrical pressure vessel, a discharge pipe section and a liquid nitrogen refrigeration system that enables conditioning near the triple point – at ∼0.7 MPa, 223 K - and higher liquid pressures (∼2.6 MPa, 263 K). Pressure, temperature and mass monitoring were considered to enable an extensive observation of the leakage behaviour under typical operation scenarios. Three different sets of experiments were considered to inform the designer in the selection of optimal process conditions, with low-pressure (0.7 – 0.94 MPa, 223–228 K), medium-pressure (1.34–1.67 MPa, 234–245 K) and high-pressure tests (1.83–2.65 MPa, 249–259 K) demonstrating distinct behaviours relative to phase transitions, leakage duration and solidification of inventory.