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Wetting phenomena have been widely observed in our daily lives, such as dew on lotus leaf, and applied in technical applications, e.g., ink-jet printing. In contrast to constant liquid–solid and solid–gas interfacial tensions in Young's law, we here focus on the wetting phenomena by considering varying fluid–solid interfacial tensions. We analyze the energy landscape, the map of Young's contact angle, the number and corresponding contact angle of local energy minima, and the contact angle hysteresis for a liquid droplet on a solid substrate in a gas phase. In addition, a gas bubble on a solid substrate in a liquid phase has been scrutinized from the aspect of surface energy minimization. The wetting effect has been regarded, where the liquid and gas species penetrate into the solid phase on the microscopic scale [F. Wang and B. Nestler, Phys. Rev. Lett. 132, 126202 (2024)]. We assume the liquid–solid and the solid–gas interfacial tensions to be a function dependent on the volume fraction of the liquid and the gas species and investigate the impact of the size ratio of the droplet to the solid surface that is overlooked in existing theories on the wetting phenomena. Our finding sheds light on the microscopic origin of the contact angle hysteresis and the droplet size effect on the wetting phenomena. [ABSTRACT FROM AUTHOR]

In molecular physics, it is often necessary to average over the orientation of molecules when calculating observables, in particular when modeling experiments in the liquid or gas phase. Evaluated in terms of Euler angles, this is closely related to integration over two- or three-dimensional unit spheres, a common problem discussed in numerical analysis. The computational cost of the integration depends significantly on the quadrature method, making the selection of an appropriate method crucial for the feasibility of simulations. After reviewing several classes of spherical quadrature methods in terms of their efficiency and error distribution, we derive guidelines for choosing the best quadrature method for orientation averages and illustrate these with three examples from chiral molecule physics. While Gauss quadratures allow for achieving numerically exact integration for a wide range of applications, other methods offer advantages in specific circumstances. Our guidelines can also be applied to higher-dimensional spherical domains and other geometries. We also present a Python package providing a flexible interface to a variety of quadrature methods. [ABSTRACT FROM AUTHOR]

It is shown that the transport coefficients (self-diffusion, shear viscosity, and thermal conductivity) of the Weeks–Chandler–Andersen (WCA) fluid along isotherms exhibit a freezing density scaling (FDS). The functional form of this FDS is essentially the same or closely related to those in the Lennard-Jones fluid, hard-sphere fluid, and some liquefied noble gases. This proves that this FDS represents a quasi-universal corresponding state principle for simple classical fluids with steep interactions. Some related aspects, such as a Stokes–Einstein relation without a hydrodynamic diameter and gas-to-liquid dynamical crossover, are briefly discussed. Simple fitting formulas for the transport coefficients of the dense WCA fluid are suggested. [ABSTRACT FROM AUTHOR]

Breast cancer is a leading cause of cancer‐related morbidity and mortality among women globally. It arises from the abnormal proliferation of cells within breast tissue and can manifest in several subtypes, classified by the expression of hormone receptors. The main objective of this work is to assess the effect of solvent on 2‐methoxy‐4‐allylphenol's (2M4AP) in quantum chemical calculations and ability of 2M4AP to bind with the proteins associated with breast cancer. The non‐toxic nature of 2M4AP was initially validated through drug‐likeness studies and it complies with Lipinski's criteria. The optimization of 2M4AP structure was carried out in gas and liquid phase in DFT technique with B3LYP/6‐311++G (d, p) level. Then the electronic spectrum was calculated in TD‐DFT technique and the transition was determined to be n → σ*. The steadiness, charge dispersal and electronic properties were assessed and the band energy value was calculated to be 5.58 eV (gas) and 5.64 eV (liquid), exhibiting a stable confirmation of 2M4AP structure. Topological characteristics exhibited the intermolecular connections of 2M4AP along with electronic features. From the simulated results, the effect of solvent (water) in 2M4AP was very minimal and the structure is stable in both gas and liquid phase. Further, the docking studies, 2M4AP exhibited highest binding score of −7.3 kcal/mol with progesterone receptor, confirming the better ability of 2M4AP to react in hormone‐positive breast cancer. The Ramachandran plot confirms the stability of interacted amino acids with the ligand molecule. Thus, 2M4AP can be considered as a potent candidate for treatment of breast cancer after clinical studies. [ABSTRACT FROM AUTHOR]

COSINUS will be among the first underground experiments to operate Transition Edge Sensors in a dry dilution refrigerator, measuring temperature changes on the order of μ K. A pulse tube cryocooler is used to cool down to 3K, trading simplified handling, by not using liquid noble gases, for an increased vibration noise level in the acoustic frequency range. As the signals measured with a TES are in the same frequency region, it is necessary to decouple the detectors from all possible noise sources. In COSINUS, a two-level passive decoupling system was developed and tested using piezo-based accelerometers. At the first level, the refrigerator is mechanically isolated from all external noise sources. For the second level an internal spring-based system was developed and tested on a mockup system. On the first level a reduction of the vibrational background up to a factor 4 below 10 Hz could be measured. On the second level a resonance frequency of 1.2 Hz with damping of higher frequencies was achieved. [ABSTRACT FROM AUTHOR]

Plasma‐activated mist (PAM) has seen increasingly widespread applications in areas such as surface disinfection and fog cultivation. The high‐resolution time diagnostics of ns pulse plasma interacting with micron‐sized droplets under high‐humidity conditions is challenging to achieve with existing experimental methods. This paper employs a global model to study the interaction between plasma and droplets, offering a detailed analysis of the plasma's transition from the gas phase to the liquid phase. It was discovered that in high‐humidity environments, hydrated ions become the predominant ion species. These acidic active substances in PAM droplets are the primary factors in the mist's ability to kill bacteria. The paper further examines how variations in droplet size and discharge voltage influence the PAM's activity. [ABSTRACT FROM AUTHOR]

This contribution focuses on the spatial‐temporal behavior and reactive pathways of O3 produced by a surface air microdischarge in the gas and liquid phase using ultraviolet absorption spectroscopy. The findings demonstrate that mode transition from ozone to nitrogen oxide over time is observed at a constant input power higher than ~0.60 W/cm2. Due to the long‐lived characteristic and ionic wind, the perpendicular distribution of O3 is almost uniform. The maximum penetration depth is around 5 mm, and the gas–liquid mass transfer efficiency is approximately 0.4‱ at a depth of 1 mm, when the treatment time is 10 min. The mass transfer of O3 between gas and liquid phases is dominated by the liquid convention induced by ionic wind. [ABSTRACT FROM AUTHOR]

After spending several years as net importer of natural gas, the development of unconventional gas reserves in Argentina can revert this scenario and change the dynamics of the Southern Cone regional gas integration. To assess the role of Argentine gas, this study utilised the TIMES-ConoSur optimisation model, which represents the regional integration of the gas and electricity systems. To improve the level of detail of the results, updates and modifications in different settings were made in the first version of the model. In addition, four scenarios were tested with two levels of LNG (liquefied natural gas) prices and including or not the interconnection between Argentina gas network and Brazil integrated network. The role of the Argentine gas was analysed based on its production potential and the export potential to the neighbour countries. Findings indicated that the development of the Argentine gas reserves can be a game changer, as it can affect directly the regional dynamics and the gas supply of the neighbour countries. The main future dynamics of the other countries in the region were also assessed, such as the role of Bolivian gas, the challenges to develop pre-salt gas and how will be the future of LNG in the region. [ABSTRACT FROM AUTHOR]

Background: Techniques for the preparation of grafts for Descemet membrane endothelial keratoplasty (DMEK) can be classified into those that involve the manual dissection of the Descemet membrane (DM) and those that use an injection of a liquid or a gas to achieve a separation of the DM from the posterior corneal stroma. The purpose of this study was to evaluate the efficiency of the liquid bubble technique. Methods: The success rate of the technique was calculated retrospectively using the operating reports. Video files for each graft preparation were retrieved and the time, number of injections, and number of injections sites required for the hydrodissection were measured. The number of cases in which a manual dissection of the Descemet membrane was necessary was recorded. Information on donor age and graft preservation time were retrieved from the eye bank file. Results: In 58 cases, the success rate was 98.3%. In the 28 procedures where a video was available, the median time for hydrodissection was 4.4 min. The median number of injection sites was 2, with a median number of injections of 3.5. Manual dissection as a rescue technique was performed in 25% of cases, with one case resulting in graft tears. The mean graft diameter was 7.6 mm. The mean donor age was 66 years, and the mean graft storage time was 22 days. Conclusions: The liquid bubble technique can be a fast and valuable choice for DMEK graft preparation, especially in centers where the tissue is prepared in the operating theater. [ABSTRACT FROM AUTHOR]

Dunaliella salina is a green microalga extensively explored for β-carotene production, while knowledge of its lipid composition is still limited and poorly investigated. Among lipids, polar lipids have been highlighted as bioactive phytochemicals with health-promoting properties. This research aimed to provide an in-depth lipidome profiling of D. salina using liquid and gas chromatography coupled with mass spectrometry. The lipid content was 6.8%, including phospholipids, glycolipids, betaine lipids, sphingolipids, triglycerides, diglycerides, and pigments. Among the total esterified fatty acids, 13.6% were 18:3 omega-3 and 14.7% were 18:1 omega-9. The lipid extract of D. salina showed anti-inflammatory activity by inhibiting cyclooxygenase-2 activity at 100 µg/mL, dose-dependent antioxidant scavenging activity, and antidiabetic activity by inhibiting α-glucosidase activity at 25 and 125 µg/mL. In conclusion, the lipid extract of D. salina has the potential to be used as a functional food ingredient or in the nutraceutical and cosmeceutical industries. [ABSTRACT FROM AUTHOR]

Dynamic gas–liquid separator (DGLS) can efficiently separate gas and liquid phases and are widely used in aerospace, chemical, and petroleum engineering. The energy loss and separation efficiency within the DGLS are studied through the combination of numerical simulations and experiments. Three-dimensional transient Reynolds-Averaged Navier–Stokes equations were solved to analyze the fluid dynamics within the DGLS. The bubble aggregation and breakup in oil were simulated by using the population balance model. Experimental data were meticulously compared with numerical results to validate the accuracy and reliability of the numerical methods. The findings revealed a direct correlation between the inlet flow rate and various performance metrics of the DGLS. Specifically, as the inlet flow rate increased, the energy loss within the DGLS escalated, resulting in higher power consumption. The degassing rate of the DGLS exhibited a decreasing trend with increasing inlet flow rate, while the de-oiling rate showed an inverse relationship. The optimal performance of the separator was observed at an inlet flow rate of 140 m3·d−1, with ηg* and ηl* reaching 0.94 and 0.99, respectively. The relationship between the Qo and the η* and Po was fitted by a second-order polynomial. Moreover, the rotational speed of the DGLS demonstrated a positive correlation with energy consumption, accompanied by an increase in power output. However, the separation efficiency of the DGLS exhibited a non-linear relationship with rotational speed, peaking at a specific value before marginally declining. The optimization of degassing and dewatering rates occurred at a rotational speed of 2500 r·min−1. These findings underscore the importance of carefully adjusting operational parameters to achieve optimal performance and energy efficiency within DGLS. [ABSTRACT FROM AUTHOR]

In order to study the hydrocarbon generation (HCGE) characteristics of coal‐bearing basins, the coal‐measure source rocks of the Middle Jurassic–Lower Jurassic (MLJ) of the piedmont thrust belt in the southern margin of the Junggar Basin in Northwest China are taken as research objects. More than 60 MLJ samples were collected from outcrops and wells. Total organic carbon (TOC), rock pyrolysis (Rock–Eval), organic petrological, vitrinite reflectance (%Ro), and hydrous pyrolysis were performed to analyze the relevant samples. The pyrolysis gases and liquid products were measured, and then the chemical composition, as well as carbon isotopes of the gases, were analyzed. The results indicate that the MLJ source rocks have the capacity for large‐scale gas generation. In addition, for coal‐measure source rocks, the heavier the carbon isotope of kerogen (δ13Ckerogen), the lower the liquid hydrocarbon and hydrocarbon gas yield, and the easier it is to produce non‐hydrocarbon gas. It is worth noting that when the δ13Ckerogen in organic matter (OM) is relatively heavier, the fractionation of its products may become weaker in the evolutionary process. The vital contribution of the MLJ source rock to natural gas resources in the study area was further confirmed by comparing it with the Jurassic source gas. [ABSTRACT FROM AUTHOR]

Purpose: In response to the challenges posed by the conventional manual flange docking method in the LNG (Liquefied Natural Gas) loading process, such as low positioning accuracy, constraints on production efficiency and safety hazards, this study analyzed the LNG five-axis loading arm's main functions and structural characteristics. Design/methodology/approach: An automated solution for the joints of the LNG loading arm was designed. The forward kinematic model of the LNG loading arm was established using the Denavit–Hartenberg (D-H) parameter method, and its workspace was analyzed. The Newton–Raphson iteration method was employed to solve the inverse kinematics of the LNG loading arm, facilitating trajectory planning. The relationship between the target position and the joint variables was established to verify the stability of the arm's motion. Flange center identification was achieved using the Hough transform function. Based on the ROS platform, combined with Gazebo and Rviz, an experimental simulation of automatic docking of the LNG loading arm was conducted. Findings: The docking errors in the XYZ directions were all less than 0.8 mm, meeting the required docking accuracy. Moreover, the motion performance of the loading arm during docking was smooth and free of abrupt changes, validating its capability to accomplish the automatic docking task. Originality/value: The proposed trajectory planning and automatic docking scheme can be used for the rapid filling of LNG filling arms and LNG tankers to improve the efficiency of LNG transportation. In guiding the docking, the proposed automatic docking scheme is an accurate and efficient way to improve safety. [ABSTRACT FROM AUTHOR]

Most of the reported self‐healing materials focus on the structure and function recovery, the influence of the damage degree on the self‐healing process has been rarely studied. In this study, an elastomer with an adaptive self‐healing function is developed based on programmable dissociation of dynamic urea bonds. The stored entropy and reversible hydrogen bonding enable the elastomer with room‐temperature self‐healing performance as the scratch depth is less than 100 µm. Thermal treatment at 75 °C is capable of inducing the cleavage of secondary urea bonds, which accelerate the dissociation of the network, leading to the repair of the middle‐size damage. Continuous increasing the temperature to 120 °C enables the dissociation of primary urea bonds, which causes further dissociation of the network, resulting in the repair of large‐scale damage. This damage‐adaptive self‐healing performance can be well maintained in an aqueous environment, and obvious improvement in the healing rate is achieved due to the water‐accelerated dissociation of urea bonds. The underwater self‐healing rate is more than 360 times faster than that in the air. Incorporation of carbon nanotubes into the network enables remote self‐healing function due to the photo‐thermal transition after irradiated by NIR light, displaying great potential in underwater gas or liquid transportation. [ABSTRACT FROM AUTHOR]

The use of homogeneous catalysts dissolved in ionic liquids (ILs) is an established field of research. Thin IL films containing dissolved catalyst complexes can be immobilized on solid porous supports, thereby creating a heterogenized catalyst material. Aiming at the deliberate positioning of such supported ionic liquid phase (SILP) catalyst, we carried out investigations of two very similar Pt‐complexes: depending on the ligand periphery, the first one is homogeneously dissolved in the IL while the second one strongly enriches at the gas/IL interface. To study these different locations within thick IL films of approximately 1 mm thickness, we investigated the hydrogenation of ethene in a continuous pool‐reactor setup. The two complexes dissolved in the IL [C4C1Im][PF6] showed different activity which can be attributed to their different locations. At 313 K and 0.62 MPa total pressure, the surface‐enriched complex was approximately two times more active. However, under these conditions the formation of Pt particles could be observed, with the surface‐enriched complex exhibiting a stronger tendency for particle formation compared to the one homogeneously distributed in the IL, as derived from XPS and light‐scattering measurements. [ABSTRACT FROM AUTHOR]

Porous liquids (PLs) represent a new frontier in material design combining the merits of solid porous host and liquid phase in gas separation and catalysis. Herein, the PL construction approach is harnessed to tailor the gating effect of organic cages toward enhanced gas separation. A type‐II fluorinated PL (F‐PL) is developed via liquifying a fluorinated organic cage (F‐cage) by a fluorinated ionic liquid (F‐IL). The F‐cage is featured by a small window size (≈5.1 Å), high surface area, good stability under highly ionic conditions, and abundant fluorine moieties. The F‐IL possesses high steric hindrance (bulky cation) and structure similarity with the F‐cage (fluorinated alkyl chain in the anion). The existing status structure integrity of F‐cage in F‐IL upon F‐PL formation is illustrated via spectroscopy and X‐ray‐based techniques. The existence of rigid voids in F‐PL is illustrated by positron annihilation lifetime spectroscopy (PALS) and the improved gas uptake capacity than F‐IL via pressure‐swing CO2 uptake isotherms (0−40) bar. The comparison of the gas uptake behavior (CO2, N2, CH4, and Xe) of F‐PL and F‐cage, combining the computational simulation, highlights that the PL construction can be leveraged to tune the window size of porous scaffolds, leading to enhanced gas selectivity. [ABSTRACT FROM AUTHOR]

During Fuel Cell Vehicle (FCV) operation, the liquid water in gas diffusion media (GDM) prevents the reaction gas from reaching the reaction zone and lead to output power fluctuation and reduce the lifespan of FCV. In the present research, hydrophobicity gradient settings of micro-porous layer (MPL) and gas diffusion layer (GDL) are optimized to improve the water removal ability of GDM. Computational fluid dynamics (CFD) model is constructed for numerical simulations to analyze the fuel cell power output and the water content in the GDM with different hydrophobicity gradients. Experiments with different hydrophobicity gradients, which are specifically prepared with corresponding concentrations of polytetrafluoroethylene (PTFE) solutions, are conducted for validation of simulation results. It is shown that the positive hydrophobicity gradient of MPL and GDL provides a better capacity for water removal and oxygen transport. The contact angles of MPL and GDL are further optimized as 147.9°-138.6° by genetic algorithm integrated with the CFD simulations. [ABSTRACT FROM AUTHOR]

While exploring and developing oil and gas, well kick and overflow accidents are inevitable. In such an accident, if the drilling bit is not at the bottom of the well, the drilling tool is blocked, or the reservoir contains toxic gases such as hydrogen sulfide, the traditional technique for well control is no longer suitable, and the bullheading method must be adopted to kill the well. However, during bullheading, the flow patterns of gas and liquid are intricate, making gas velocity hard to predict. To solve these problems, a set of visual simulation experimental device for directional well bullheading was built to find out the effects of wellbore inclination, liquid viscosity, gas and liquid velocities, and bubble size on bubble migration characteristics in gas–liquid countercurrent (gas flowing in opposite direction to the liquid). Prediction models of bubble distribution coefficient and rising velocity considering liquid viscosity, bubble size, and wellbore inclination angle were worked out. The experimental results show that small bubbles are mainly located in the center of the wellbore and large bubbles tend to approach the wellbore wall in gas–liquid countercurrent. Increasing wellbore inclination, viscosity, and the velocity of the liquid flowing against the bubbles results in a gradual decrease in Taylor bubble migration speed, which promotes the bubbles' pressing-back, as inhibiting the upward movement of large bubbles is essential for effective bullheading operations. The prediction models of distribution coefficient and bubble migration velocity have an error of less than 10% and 9. 78%, respectively. [ABSTRACT FROM AUTHOR]

To handle multiphase (i.e., gas–liquid–solid) flow problems, an algorithm coupling the CLSVOF/IB (coupled level set and volume of fluid/immersed boundary) method with adaptive mesh refinement (AMR) for simulating multiphase flows is proposed in this paper. First, in order to accurately predict the gas–liquid interface, intermediate, re-distancing, and second reconstruction steps are incorporated are added. Second, the CLSVOF/IB method has been developed to handle the gas–liquid interface and the fluid (including gas phase and liquid phase)–solid interface. The direct forcing IB method is employed, which utilizes an artificial force at specific cells that contain both fluid and solid phases. Finally, in order to more accurately calculate the IB force term at the fluid–solid interface, an AMR-CLSVOF/IB coupling algorithm for simulating multiphase flow is developed, in which meshes near the gas–liquid interface and the fluid–solid interface are refined at each time step. The biggest advantage of this coupling way is that besides refining meshes at the gas–liquid interface for enhanced fluid detail capture, the meshes near the solid structure are also refined, so that the IB force cells can be used to effectively describe the actual solid boundary. By using the proposed AMR-CLSVOF/IB method, accurate simulations of dam-break flows impacting fixed structures are achieved, enabling detailed capture of water flow and splash breakup phenomena. [ABSTRACT FROM AUTHOR]

The temperature at the liquid–vapor phase change interface is measured at the molecular mean free path scale. The water layer is locally heated from below and evaporates in an environment of pure water vapor at reduced pressure. The study establishes the equilibrium conditions under which gas and liquid phases are maintained at a constant temperature without a temperature jump at the interface. It also examined how applying heat to the liquid causes the interface to enter a non-equilibrium state. The first experimental validation of the long-standing inverted temperature gradient paradox is also provided. Nonlinear kinetic theory is shown to be in quantitative agreement with the experimental results. [ABSTRACT FROM AUTHOR]

The finite volume method (FVM) is used to numerically investigate the sloshing behaviors of dual liquid tanks with gas inflow in this study. The sloshing process of a single liquid tank is simulated to verify the feasibility of the numerical method. Three different inlet boundary conditions are then discussed in order to obtain a reasonable gas flow rate. The sloshing process of a dual liquid tank with the gas inflow is simulated, and the effects of three different factors on the sloshing behaviors are investigated. The results indicate that the overload, flow rate, and filling ratio can affect the peak value of the impact force acting on the tank wall. The impact force is positively proportional to the overload (1G, 3G, or 5G). An increase in flow rate (50 g/s, 1000 g/s, or 5000 g/s) or a decrease in filling ratio (99.52%, 75.64%, or 63.69%) can increase the size and number of bubbles, leading to intensified sloshing behavior and increased impact force. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to explore the optimization of support structures for horizontal pressure vessels using simulation modeling. The research aims to reduce the mass of the support while ensuring structural integrity and identifying opportunities for future improvements in materials and design. Design/methodology/approach: The research was conducted by creating a three-dimensional support model in SolidWorks, compliant with GOST standards. The stress-strain behavior and optimization of the support structure were analyzed using SolidWorks’ Simulation module, which employs the finite element method (FEM). Non-uniform load distributions, such as sinusoidal and parabolic loads, were applied during the loading process to enhance the accuracy of the simulation without incorporating the vessel body itself. Findings: The simulation results showed that optimizing the support structure led to a 15% reduction in its mass. Even though this also resulted in a 23% increase in equivalent stresses in critical areas, the support structure remains safe to operate, with a strength reserve factor under static loads exceeding 2. Research limitations/implications: Further research should include simulations that account for the type and properties of connections between elements, particularly weld calculations. Additionally, future studies could explore the use of higher-grade steels than the tested 09G2C steel to achieve further mass reductions, provided the cost is justifiable. Practical implications: This study is particularly relevant for the design of pressure vessel supports used in vehicles, trailers, and semi-trailers transporting liquids or liquefied hydrocarbon gases. Reducing the mass of support structures can increase payload capacity, offering significant commercial benefits in transportation efficiency. Social implications: A lighter, optimized support structure can contribute to more fuel-efficient transportation of liquid and gas materials, thereby reducing the environmental impact of logistics operations. Originality/value: The originality of this study lies in the combined use of topological and parametric optimization techniques for modeling horizontal pressure vessel supports. The paper provides valuable insights into how simulation-based optimization can lead to significant mass reductions while maintaining structural safety. This research is particularly useful to engineers and designers working on pressure vessel supports for transportation applications. [ABSTRACT FROM AUTHOR]

In this study, cargo boil-off gas (BOG) re-liquefaction systems for ammonia-fueled liquefied carbon dioxide (LCO2) carriers were analyzed. These systems use cold energy from ammonia to reliquefy the CO2 BOG. In this study, a system that can completely reliquefy the CO2 BOG at all engine loads using only one heat exchanger is proposed, instead of the existing cascade system that requires multiple components. R744, which has a low global warming potential, was used as the working fluid for the refrigeration cycle in the CO2 BOG re-liquefaction system. The organic Rankine cycle (ORC) was used to reduce the net power consumption of the system. The existing and proposed systems were classified into Case 1 (existing system), Case 2 (our proposed system), and Case 3 (Case 2 combined with an ORC). Thermodynamic and economic analyses were conducted. Case 2 is a system with a simpler configuration than Case 1, but it has a similar thermodynamic performance. Case 3 has a higher exergy destruction rate than Cases 1 and 2, owing to the ORC, but it can significantly reduce the net power consumption. The economic analysis shows that Cases 2 and 3 reduce the total annual costs by 17.4% and 20.1%, respectively, compared to Case 1. The proposed systems are significantly more advantageous for long-term operation than existing systems. [ABSTRACT FROM AUTHOR]

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Unfavorable fluid‐fluid displacement, where a low‐viscosity fluid displaces a higher‐viscosity fluid in permeable media, is commonly encountered in various subsurface processes. Understanding the formation and evolution of the resulting interfacial instability can have practical benefits for engineering applications. Using gradient capillary tubes as surrogate models of permeable media, we numerically investigate interfacial dynamics during gas‐driven drainage. Our focus is on understanding the impact of tube geometry on interface stability. In a gradient tube, since the interface shape changes during the drainage process, we measure interfacial stability using the difference between the contact‐line velocity Ucl and the meniscus tip velocity Utip. We define instability as a rapid reduction in the contact line velocity Ucl compared to the tip velocity Utip. Beyond the onset of this instability, gas penetrates into the liquid, forming a finger, and entraining a liquid film on the tube wall. The observed stability transition can be rationalized to a large extent by adaptation of an existing theory for cylindrical tubes in terms of a critical capillary number Cacrit. For an expanding tube, simulations suggest that a stability transition from an initially unstable meniscus to a final stable one, with Ucl catching up with Utip, can occur if the local capillary number is initially slightly larger than Cacrit and then drops below Cacrit. The insights gained from this study can be beneficial in estimating the mode and efficiency of subsurface fluid displacement. Key Points: We numerically investigate the dynamics of a gas‐liquid interface during drainage in a gradient capillary tubeThe observations from our numerical simulations can be rationalized by an adapted theoretical modelWe find a unique stabilization in drainage along expanding tubes, suppressing film entrainment even when the system is initially unstable [ABSTRACT FROM AUTHOR]

The velocity autocorrelation function (VACF) encapsulates extensive information about a fluid's molecular-structural and hydrodynamic properties. We address the following fundamental question: How well can a purely hydrodynamic description recover the molecular features of a fluid as exhibited by the VACF? To this end, we formulate a bona fide hydrodynamic theory of the tagged-particle VACF for simple fluids. Our approach is distinguished from previous efforts in two key ways: collective hydrodynamic modes and tagged-particle self-motion are modeled by linear hydrodynamic equations; the fluid's spatial velocity power spectrum is identified as a necessary initial condition for the momentum current correlation. This formulation leads to a natural physical interpretation of the VACF as a superposition of products of quasinormal hydrodynamic modes weighted commensurately with the spatial velocity power spectrum, the latter of which appears to physically bridge continuum hydrodynamical behavior and discrete-particle kinetics. The methodology yields VACF calculations quantitatively on par with existing approaches for liquid noble gases and alkali metals. Furthermore, we obtain a new, hydrodynamic form of the self-intermediate scattering function whose description has been extended to low densities where the Schmidt number is of order unity; various calculations are performed for gaseous and supercritical argon to support the general validity of the theory. Excellent quantitative agreement is obtained with recent MD calculations for a dense supercritical Lennard-Jones fluid. [ABSTRACT FROM AUTHOR]

The short-term and long-term performance of bituminous geomembrane (BGM) seams are examined using both small-scale and large-scale tests. Different BGM products, different sustained tensile loads, different weld qualities, and different overburden stresses are examined. The BGM seams are shown to be very susceptible to creep rupture under sustained tensile loads. Time to rupture and strain at rupture for acceptable welds are both exponentially correlated with the sustained load, for the different BGM products examined. With the increasing tensile load from 5%, 10%, 20%, 30%, 40% of sheet maximum tensile strength, the time to rupture decreased from 30–50 days (5%), 5 days (10%), 0.8 day (20%), 0.2 day (30%), to 0.03 day (40%) and, the strain at rupture increased from 5%, 7%, 13%, 17%, to 20–30%. In large-scale tests simulating field conditions, the BGM seam creep ruptured within 24 days when the overburden stress was 20 kPa, and within ≤0.2 day when the overburden stress reached 50 kPa. The consequences of liquids or gases readily permeating through failed seam should be evaluated before using BGMs in an environment where tensile stresses can develop (e.g. due to differential settlement, subgrade irregularity, or downdrag). • first investigation of the creep rupture of different BGM seams at sustained tensile loading as small as 1 kN/m. • first evaluation of the creep behavior of different BGM seams under simulated field conditions. • first correlations of time to rupture and strain at rupture both with a wide range of sustained tensile loads. [ABSTRACT FROM AUTHOR]

We develop and harness a phase field simulation method to study liquid filling on grooved surfaces. We consider both short-range and long-range liquid–solid interactions, with the latter including purely attractive and repulsive interactions as well as those with short-range attraction and long-range repulsion. This allows us to capture complete, partial, and pseudo-partial wetting states, demonstrating complex disjoining pressure profiles over the full range of possible contact angles as previously proposed in the literature. Applying the simulation method to study liquid filling on grooved surfaces, we compare the filling transition for the three different classes of wetting states as we vary the pressure difference between the liquid and gas phases. The filling and emptying transitions are reversible for the complete wetting case, while significant hysteresis is observed for the partial and pseudo-partial cases. In agreement with previous studies, we also show that the critical pressure for the filling transition follows the Kelvin equation for the complete and partial wetting scenarios. Finally, we find the filling transition can display a number of distinct morphological pathways for the pseudo-partial wetting cases, as we demonstrate here for varying groove dimensions. [ABSTRACT FROM AUTHOR]

Environmental cells sealed with photoelectron‐transparent graphene windows are promising for extending X‐ray photoelectron spectroscopy (XPS) to liquid and high‐pressure gas environments for in situ and operando studies. However, the reliable production of graphene windows that are sufficiently leak‐tight for extended measurements remains a challenge. Here we demonstrate a PDMS/Au(100 nm)‐supported transfer method that reliably produces suspended graphene on perforated silicon nitride membranes without significant contamination. A yield of ~95 % is achieved based on single‐layer graphene covering >98 % of the holes in the silicon nitride membrane. Even higher coverages are achieved for stacked bilayer graphene, allowing wet etching (aqueous KI/I2) of the Au support to be observed in a conventional lab‐based XPS system, thereby demonstrating the in situ formation of leak‐tight, suspended graphene windows. Furthermore, these windows allow gas‐phase measurements at close to atmospheric pressure, showing future promise for XPS under higher‐pressure gas environments in conventional lab‐based systems. [ABSTRACT FROM AUTHOR]

At present, stationary phases based on ionic liquids are a promising and widely used technique in gas chromatography, yet they remain poorly studied. Unfortunately, testing of "new" stationary phases is often carried out on a limited set of test compounds (about 10 compounds) of relatively simple structures. This study represents the first investigation into the physicochemical patterns of retention of substituted (including polysubstituted) aromatic alcohols on two stationary phases of different polarities: one based on pyridinium-based ionic liquids and the other on a standard polar phase. The retention order of the studied compounds on such stationary phases compared to the standard polar phase, polyethylene glycol (SH-Stabilwax), was compared and studied. It was shown that pyridinium-based ionic liquids stationary phase has a different selectivity compared to the SH-Stabilwax. Using a quantitative structure–retention relationships (QSRR) study, the differences in selectivity of the two stationary phases were interpreted. Using CHERESHNYA software, the importance of descriptors on different stationary phases was evaluated for the same data set. Different selectivity of the stationary phases correlates with different contributions of descriptors for the analytes under study. For the first time, we show that in-column dehydration is observed for some compounds (mostly substituted benzyl alcohols). This effect is worthy of further investigation and requires attention when analyzing complex mixtures. It suggests that when testing "new" stationary phases, it is necessary to conduct tests on a large set of different classes of compounds. This is because, in the case of using ionic liquids as an stationary phase, a reaction between the analyte and the stationary phase is possible. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Dietary methane (CH 4) mitigation is in some cases associated with an increased hydrogen (H 2) emission. The objective of the present study was to investigate the acute and short-term effects of acceptors for H 2 (fumaric acid, acrylic acid, or phloroglucinol) supplemented via pulse-dosing to dairy cows fed CH 4 mitigating diets (using nitrate or 3-nitrooxypropanol), on gas exchange, rumen gas, and VFA composition. For this purpose, 2 individual 4 × 4 Latin square experiments were conducted with 4 periods of 3 d (nitrate supplementation) and 7 d (3-nitrooxypropanol supplementation), respectively. In each study, 4 rumen-cannulated Danish Holstein cows were used. Each additive for CH 4 mitigation was included in the ad libitum–fed diet within the 2 experiments (exp. 1 and exp. 2), to which the cows were adapted for at least 14 d. Acceptors for H 2 were administered twice daily in equal portions through the rumen fistula immediately after feeding of the individual cow. In exp. 1 (nitrate), the treatments were CON-1 (no H 2 -acceptor), FUM-1 (fumaric acid), ACR-1 (acrylic acid), and FUM+ACR-1 (50% FUM-1 + 50% ACR-1). In exp. 2 (3-nitrooxypropanol), the 3 treatments, CON-2, FUM-2, and ACR-2, were similar to CON-1, FUM-1 and ACR-1 treatments, however the fourth treatment was PHL-2 (phloroglucinol). Gas exchanges were measured in respiration chambers, and samples of rumen liquid and headspace gas were taken in time series relative to feeding and dosing on specific days. Headspace gas was analyzed for gas composition, and rumen liquid was analyzed for VFA composition and dissolved gas concentrations. Headspace gas composition and dissolved gas concentration were only measured in exp. 2. Dry matter intake was reduced upon acrylic acid supplementation. There were no significant effects of any treatments in any experiments on H 2 emission, except for a decrease in hourly H 2 emission rate (g/h) at 1 h after feeding in both experiments. In exp. 2, H 2 headspace proportions increased with ACR-2 supplementation, whereas dissolved concentrations were unaffected. In exp. 1, cows on ACR-1 increased propionate proportion at 1 h after feeding. In exp. 2, both FUM-2 and ACR-2 increased rumen propionate proportion in the hours after feeding and dosing. There was no effect on rumen acetate for cows on PHL-2. There was a strong positive correlation between rumen dissolved CH 4 and headspace CH 4 (r = 0.84), whereas the equivalent correlation was weaker for H 2 (r = 0.41). For the relationship between dissolved concentrations and emissions of CH 4 and H 2 , there was a moderate positive correlation for CH 4 (r = 0.54), whereas it was weak for H 2 (r = 0.28) with zero slope. In conclusion, the results suggested that fumaric acid and acrylic acid to some extent was reduced to propionate without associative effects on measures for H 2 redirection. Furthermore, phloroglucinol seemed not to be metabolized in the rumen in the present study, because no effects on rumen acetate or measures of H 2 were observed. Changes in H 2 headspace and emission may be a poor proxy for actual changes in the rumen fluid concentration of H 2. [ABSTRACT FROM AUTHOR]

To determine the spray characteristics of internal-mixing gas-liquid injector under various operating conditions, the experimental facilities for spraying are established. By means of high-speed camera, laser particle size analyzer and PIVlab, the effects of gas and liquid flow conditions on the spray characteristics, such as position of jet impingement, spray angle, breakup length, velocity distribution and droplet size, have been investigated in detail. Experimental results demonstrated that there are two types of atomization for this injector, namely impact atomization and aerodynamic atomization. The impingement position of the liquid jets is outside of the injector exit. Alternatively, no impingement occurs between the jets. The spray angle increases with the increase of liquid flow rate, and decreases with the increase of gas flow rate. The breakup length decreases with the increase of the liquid or gas flow rate. The higher the liquid flow rate, the greater the velocity distributed along the axial and radial direction. However, the effect of gas flow rate on the velocity along the axial and radial directions acts differently at different spatial position. An increase in the liquid flow rate causes the droplet diameter to increase first and then decrease. The droplet size will decrease when the gas-liquid momentum ratio increases. • Two types of atomization process: "aerodynamics fragmentation" and "impact fragmentation". • Effects of gas/liquid flow rates on the position of jet impingement, spray angle, breakup length, velocity distribution and droplet size. • Effects of operating conditions on the two atomization mechanisms: "aerodynamics fragmentation" and "impact fragmentation". • The dominant factor (mutual impact between the liquid jets or gas-liquid interaction) in atomization process depends on the gas flow rate. [ABSTRACT FROM AUTHOR]

The oxygen discharge process significantly affects the electrochemical performance of a proton exchange membrane water electrolyzer (PEMWE), which requires an optimal structure of the flow field implemented in the bipolar plate (BP) component. In this study, we numerically investigated the two-phase (liquid water and oxygen) flow in the PEMWE's channel region with different outlet manifold structures utilizing the volume of fluid (VOF) model. Then, the oxygen volume fraction at the liquid/gas diffusion layer (L/GDL) surface, i.e., the interface of the channel and L/GDL, obtained by the liquid water and oxygen flow model was incorporated into a three-dimensional (3D) PEMWE model, which made it possible to predict the influence of the outlet manifold structure on the multiple transfers inside the whole electrolyzer as well as the electrochemical performance. The results indicate that the existence of oxygen in the flow field significantly decreased the electrolyzer voltage at a fixed operation current density and deteriorated the uniform distribution of the oxygen amount, current density (corresponding to the electrochemical reaction rate) and temperature in the membrane electrode assembly (MEA), indicating that the rapid oxygen removal from the flow field is preferred in the operation of the electrolyzer. Moreover, slight increases in the width of the outlet manifold were helpful in relieving the oxygen accumulation in the anode CL and, hence, improved the electrolyzer performance with more uniform distribution characteristics. [ABSTRACT FROM AUTHOR]

Stretchable electronic fibers are essential for soft electronics because of their small footprint, light weight, high compliance, and ease of integration. To date, the majority of stretchable electronic fibers are fabricated with solidly filled fiber substrates where the exchange of gas or liquid between the outer environment and the inner part of the fiber is largely inhibited, if not impossible. The nonpermeability largely wastes the inner volume of the fiber, especially for those sensor fibers. Here, a continuous fabrication of permeable and super‐stretchable liquid metal fibers for constructing high‐integration‐density and multifunctional electronic fibers are reported. The electronic fiber is comprised of self‐assembled porous elastomer fibers and multilayers of coaxially arranged liquid metal circuits patterned in the three‐dimensional space of the fiber matrix. The micron‐scale porous structure of the fiber matrix enables high permeability for effective materials/energy exchange between the surrounding environment and the components in different layers of the fiber. As a proof of concept, a stretchable multifunctional electronic fiber incorporated with three individual layers responsible for lighting, data transmission, and biochemical sensing, as well as an artificial neuron integrating multi‐modal sensing and electrical signal transmission capabilities, illustrating the potential of the fiber fabrication strategy for stretchable electronics applications is demonstrated. [ABSTRACT FROM AUTHOR]

In order investigate the effects of different pyrolysis temperatures and catalysts on the pyrolysis products of polypropylene (PP), the gas and liquid products were characterized respectively. The results showed that the least amount of CO2 and the highest content of combustible gases were produced at the high temperature pyrolysis of 700 °C. The H/C ratio was significantly improved to 1.77 with the in-situ catalytic pyrolysis of CaO (5 g), and more aromatic compounds were converted into aliphatic ones at this time. When C (5 g) and CaO (5 g) were used separately for ex-situ catalytic pyrolysis, the total amount of alkanes and alkenes obtained was the highest, making the liquid products more suitable as fuels. Moreover, PP pyrolysis at 700 °C can produce more combustible gases, which is beneficial for secondary utilization. When C and CaO are used as catalysts in the catalytic pyrolysis of PP, more high-quality pyrolysis liquid products can be produced. [ABSTRACT FROM AUTHOR]

To investigate the flow characteristics of sieve tray columns with circular downcomers, the Euler–Euler gas–liquid two‐phase flow model is used to simulate a three‐dimensional sieve tray column. Each phase is regarded as an interpenetrating continuum with independent transport equations. The velocity distribution, clear liquid height, and foam layer height are predicted by the model. The correlation is established for predicting the clear liquid height on the sieve tray. The results show the following: (1) The sensitivity of the clear liquid height to the gas phase load is greater than that of the liquid phase load. (2) When the gas–liquid distribution is stable, the flow on the round sieve tray column presents a piston flow pattern. (3) The average liquid holdup of the circular downcomer of the three heights all showed a slow decrease at first, and then an inflection point appeared near the height of 0.02 m, after which the liquid holdup dropped sharply. (4) The established correlation has good predictive performance for calculating the clear liquid height in the column, and the relative error between the calculated value and the actual value is less than 10%. [ABSTRACT FROM AUTHOR]

Although paper packages are biodegradable, their applications in food packaging are limited due to high affinity for absorbing moisture and the high permeability of gases and liquids with surroundings. Therefore, exploring the use biodegradable coatings such as nanocellulose to improve barrier is a relevant strategy. This study assessed the efficacy of unbleached nanofibrillated cellulose (NFC) as an additive to paper and coatings. Using NFC derived from unbleached eucalyptus pulp, a 5% mass addition to the paper pulp and a 2 mm wet nanocellulose coating to kraft paper handsheets made from pine pulp were investigated. In addition, nanocellulose films of similar thicknesses were appraised. The physical, morphological, mechanical, and thermal characteristics of the resulting papers were assessed. Incorporating NFC notably enhanced the morphology area of the paper by padding its pores, thus increasing its density by up to 48% and improving its water barrier properties by up to 50%. The mechanical strength showed significant enhancements, particularly in bursting and tensile strength with increases of up to 134% and 50%, respectively. Anyhow, the films exhibited lower bursting indices and no improvement in the tearing index. Nonetheless, the thermal stability of the handsheets with NFC coating meets the minimum requirements for food packaging. [ABSTRACT FROM AUTHOR]

Microfiltration is a commonly used pressure-driven membrane separation process for various applications. Depending on the manufacturing method, either tortuous or capillary pore structures are obtained. The structure plays an important role in controlling flux, selectivity, but most importantly, the fouling tendency of the membrane. This review attempts to cover past and current developments in physical morphology and fouling characterization methods, along with the manufacturing methods for microfiltration membranes. The limitations and advantages of direct microscopic techniques and gas-liquid displacement as an indirect method are discussed for physical characterization. Additionally, the current state of the art and technical challenges for various in-situ and ex-situ fouling characterization techniques are also discussed. Finally, some directions for future research are outlined. [ABSTRACT FROM AUTHOR]

Olfactory receptors are known for their high specificity, sensitivity, and nanometer‐sized sensing element, making them ideal for in situ odorant sensor applications. However, one of the major limitations of these sensors is the requirement for an aqueous environment to maintain their function, while most odorants are poorly soluble in water. To address this issue, a microfluidic device consisting of a gas‐flow channel and a microwell is proposed that enables the effective dissolution of a gaseous odorant in an aqueous solution. Computational simulations are used to design the gas‐flow channel and the well, and the performance of the odorant dissolution is verified using the fabricated device. This study considers that convection in water induced by the gas flow enhances the dissolution of a gaseous odorant. The feasibility of the device is demonstrated for on‐site detection of a gaseous odorant. This approach facilitates the development of highly responsive and portable sensors utilizing olfactory receptors, offering a promising solution to the limitations of current odorant sensors. [ABSTRACT FROM AUTHOR]

Ambient air vaporizers (AVVs) are the most commonly used type of heat exchanger for cryogenic regasification stations. The transfer of heat from the environment for heating the liquefied gas and its vaporization is a cost-free and efficient method. Designing ambient air vaporizers for regasification or fueling stations requires accepting the size and related thermal power of the AVV considering the operating conditions and the type of liquefied gases to be vaporized. The nominal capacity of the ambient air vaporizer depends on its design, the frosting of longitudinal finned tubes, and the airflow through the vaporizer structure. This paper presents the results of experimental studies and computational fluid dynamics (CFD) analysis on determining the heat output of AVV longitudinal finned tubes depending on their design. This experiment was conducted in order to establish a numerical model. The relation between the longitudinal finned tubes thermal power and the air flow velocity is demonstrated and the beneficial effect of forced convection is proved. The obtained results are used for verification calculations of ambient air vaporizers' performance depending on the size of the AVV, the profile cross-section, and the airflow velocity for different liquefied gases. Under conditions of forced convection, profiles with 12 equal-height fins were discovered to be the most efficient for higher airflow velocity providing up to 7% higher heat rate than profiles with 8 equal-height fins. However, at low air velocity, profiles with 8 equal-length fins showed a comparable heat output to profiles with 12 equal-length fins. Profiles with 8 and 12 unequal high fins differ in average heat output by about 28%. The profile with 12 unequal high fins turned out to be the least effective when 2D airflow was considered in this analysis. [ABSTRACT FROM AUTHOR]

A hybrid cooling tower, which is a promising type of coolers, can be used successfully to cool the circulating water of industrial enterprises taking into account the modern requirements for energy efficiency, resource saving, and environmental friendliness. A hybrid cooling tower design has been developed including a sprinkler made of inclined corrugated contact elements and an internal finned tubular radiator. The purpose of the work is to experimentally determine the volumetric coefficients of heat and mass emission in the developed hybrid cooling tower for cooling circulating water. A diagram of an experimental installation of a cooling tower with hybrid cooling system is presented and described. Graphic dependences were constructed for the volumetric coefficients of mass emission and heat emission on the average flow rate of cooling air at various wetting mass densities. A dimensionless equation has been obtained for determining the volumetric coefficients of mass emission in a hybrid cooling tower with transverse finning of radiator pipes. A comparison of volumetric coefficients of mass emission for the developed cooling tower with other water-cooling devices showed the potential of its usage for cooling circulating water, especially at high ratios of gas and liquid phase loads. [ABSTRACT FROM AUTHOR]

Copyright of Atomic Energy Science & Technology is the property of Editorial Board of Atomic Energy Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Modares Mechanical Engineering is the property of Tarbiat Modares University Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

During oil production, the reservoir pressure declines, causing changes in the hydrocarbon components. To ensure better separation of produced phases, separator dimensions should also be adjusted. It is not possible to change the dimensions of the separator during production. Therefore, to improve the separation of the phases, the level of the separator needs to be adjusted. An intelligent system is required to ensure that the liquid level is maintained at the desired level for optimal phase separation during changes in reservoir pressure. In this study, a novel correlation is presented to measure the desired liquid level using new separator pressures. For this purpose, an intelligent system was built in the laboratory and tested in different operational conditions. The intelligent system effectively maintained the desired liquid level of the separator through a new correlation technique. The system accomplished this by acquiring new separator pressure readings collected by installed sensors. This approach helped mitigate the negative effects of the slug flow regime and minimized issues such as foam formation and over-flushing of the separator. It could achieve a 99.1% separation efficiency between gas and liquid phases. This was possible during liquid and gas flow rates ranging from 0 to 2.35 and 8–17 m3/h, respectively. The system could operate under bubble, stratified, plug, and slug flow regimes. Then the intelligent model obtained from lab experiments was integrated into the production model for the southern Iranian oil field. The smart model increased oil production by 13% and prevented the separator from over-flushing in 840 days. [ABSTRACT FROM AUTHOR]

The purpose of this work was to test a new setup to pump water with entrained air for application in gas fermentation. A mixed flow, where gas is contained in a liquid to be pumped, rapidly reduces the efficiency of a conventional pump, due to the compressibility of the gas. It is not always possible to degas the fluid, for instance in gas fermentation, which is preferably carried out in tubular reactors (loop fermenters) to achieve a high conversion rate of the gaseous feedstocks. Method: In this work, a rim-driven thruster (RDT) was tested in a lab-scale, cold flow model of a loop reactor with 5–30% (by volume) of gas fraction (air) in the liquid (water) as alternative propulsion element (6 m total pipe length, ambient temperature and pressure). As a result, it was found that the RDT, in connection with a guiding vane providing swirling motion to the two-phase fluid, could pump a mixed flow with up to 25.7% of gas content (by volume) at atmospheric pressure and 25 °C and 0.5 to 2 m/s flow speed. In conclusion, an RDT is advantageous over a classic propulsion element like a centrifugal pump or axial flow pump for transporting liquids with entrained gases. This article describes the potential of rim-driven thrusters, as known from marine propulsion, in biotechnology, the chemical industry, and beyond, to handle multiphase flows. [ABSTRACT FROM AUTHOR]

Transporting natural gas in liquid form increases opportunities for storage and export worldwide, thus making transportation more sustainable. However, liquefied natural gas (LNG) is in an unsteady state, leading to LNG conversion to the gas state occurring throughout the storage, loading, unloading, and transportation processes. To observe the transition of LNG to natural gas, mathematical models are developed to monitor technical parameters. This research analyses a floating storage and regasification unit for and adopts a mathematical model of the LNG regasification system, aiming for improved observation of hydrodynamic, dynamic, and thermo-physical properties. The complex mathematical model of the system was implemented using the Fortran programming language and MATLAB R28a. From the investigation of the total LNG regasification system, it could be concluded that increasing the outlet pressure of the system results in a decrease in the velocity of LNG. It was found that the total hydraulic energy losses of the total LNG regasification system were approximately 41.3 kW (with outlet pressure of 2 MPa), 12.75 kW (with outlet pressure of 5 MPa), and 4.24 kW (with outlet pressure of 7 MPa). [ABSTRACT FROM AUTHOR]

Aiming at the problem of difficult to remove high‐carbon α‐olefin in polyethylene, the influences of operation conditions and devolatilization additives on the devolatilization of LLDPE/1‐octene system in an exhaust twin‐screw extruder are studied by headspace gas chromatography. The results showed that the devolatilization efficiency increases with the devolatilization temperature and vacuum. With the screw rotational speed, the content of liquid additives and the gas velocity of gas additives increasing, the devolatilization efficiency first increases and then decreases. The devolatilization difficulty of different grades of polyethylene varies due to the difference of the viscosities. When the volatile content is high, the effect of devolatilization additives is anhydrous ethanol > surfactant > water > nitrogen. When the volatile content is low, the effect of nitrogen on devolatilization is obviously better than anhydrous ethanol and water. Finally, a novel devolatilization process is proposed, that is, an evacuation system (vacuum degree 0.08–0.1 MPa) is set up in each stage of the devolatilization section, the anhydrous ethanol is introduced in the first stage, and high‐purity nitrogen is introduced in the second, third, and fourth stages, which can ultimately reduce the VOC content of LLDPE products to less than the target value of 50 ppm. Highlights: The devolatilization process is used to remove high carbon α‐olefins from LLDPE.Each additive has an optimal injection value.Ethanol is the most effective in the foam‐dominated devolatilization stage.Nitrogen is the most effective in the diffusion‐dominated devolatilization stage.A new additive‐enhanced twin‐screw extruder devolatilization process is proposed. [ABSTRACT FROM AUTHOR]

Recommendations are given for choosing the optimal schemes for the process of inerting cargo tanks of ships carrying liquefied gases. It was determined that one of the tasks that arise during the transportation of hydrocarbon cargoes (crude oil, petroleum products, and liquefied gases) is to ensure fire safety and prevent accidental explosions of cargo vapors in cargo tanks. Processes that occur during cargo operations on ships transporting oil products and liquefied gases are considered. The critical composition of the mixture of oxygen (entering the cargo tanks with air) and cargo vapors (remaining in the tanks after the cargo is unloaded) is indicated, at which a flash and explosion may occur. It was determined that the main technological operation that prevents spontaneous ignition of cargo vapors in cargo tanks is their inerting using nitrogen. The main advantages and disadvantages of the schemes for inerting cargo tanks are considered and determined: cascade, semi-cascade and parallel. The effective use of these schemes is based on the consumption of nitrogen, the amount of which is necessary for inerting, as well as the duration of the inerting process. The results of determining these indicators for a group of gas carriers with a cargo capacity of 38,646–62,233 m³ are given. At the same time, it is stated that the lowest consumption of nitrogen is necessary to ensure the process of inerting according to the cascade scheme. It was established that semi-cascade and parallel inerting schemes require an increase in the amount of nitrogen by 1.74–2.42 times and by 1.28–1.83 times, respectively. It was also established that the cascade scheme of inerting requires more time for its implementation. The duration of inerting according to the semi-cascade and parallel scheme is reduced and is 0.43–0.64 and 0.58–0.75 times in comparison with the cascade scheme. [ABSTRACT FROM AUTHOR]

The effect of the agitators configuration, the agitator speed, the volumetric gas flow rate, the sucrose concentration in aqueous solution, and the yeast suspension concentration on the hydrodynamics of two- or three-phase systems in an agitated vessel with two agitators has been presented in this paper. The gas hold-up and the average residence time of the bubbles were measured in agitated vessel with a liquid height of H = 2D and the internal diameter of D = 0.288 m. The study was carried out for gas-liquid and biophase-gas-liquid systems, where the gas phase was air, the liquid phase was distilled water or an aqueous solution of sucrose (c = 2.5% mass., 5% mass.), and the biophase was a suspension of Saccharomyces cerevisiae yeast (ys = 1% mass.). The research results were analysed taking into account the influence of the type of the upper or lower agitator, agitator speed, gas flow rate, and type of liquid in the system on the gas hold-up and the average residence time of the gas bubbles. The experimental results were mathematically described. [ABSTRACT FROM AUTHOR]