Typical Liquid Research Articles

Dynamic monitoring of leaking oil diffusion in porous media: An improved method assisting buried oil pipeline condition assessment

The environmental pollution caused by buried oil pipeline leakage is a typical non-aqueous phase liquid (NAPL) pollution accident. Therefore, it seems more reasonable to assess the condition of buried oil pipelines considering the potential contamination range. The law of oil diffusion in porous soil is very important for the safety management of buried pipelines and the remedy of leakage accidents. This paper proposes a dynamic observation technique of NAPL in porous media for buried oil pipeline leakage. A quantitative relationship between the diesel saturation and color components is established based on the theoretical analysis combined with 21 groups of dyed diesel experimental results. The accuracy of the observation technique is verified by a quantitative analysis of a series of discrete point samplings and a comparison of diesel volume in a diesel diffusion experiment. The results show that the combination of a specified saturation boundary and the color components S and I can effectively track the diesel diffusion fronts. The relative error between the calculated cumulative volume and the injected cumulative volume fluctuates around 5% at different times. This improved technology can effectively make up for the limitation of the traditional light transmission visualization (LTV) under low-intensity light and promote the study of NAPLs diffusion characteristics. Furthermore, the dynamic observation technique of NAPL in porous media for buried oil pipeline leakage monitoring can make a significant contribution to the improvement of the level of buried pipeline leakage accidents and remediation.

Novel chiral 1,4-bis(β-cyanostyryl)benzene liquid crystals with high circularly polarized luminescence tuned by length of alkyl chains

Although some AIE-based CPL materials had been presented, the design and synthesis novel AIE-based CPL materials and studies on the relationship of structure–property were still a challenging work. Herein, series of novel 1,4-bis(β-cyanostyryl)benzene derivatives 2a, 2b and 2c bearing chiral alkyl chains were prepared, and the influence of length of alkyl chains on CPL properties were investigated for the first time. Samples 2a, 2b and 2c were synthesized by simple procedure with 83–88 % yields. Samples 2b and 2c with longer chains displayed the typical liquid crystalline properties. All of them showed strong fluorescence in both solution and aggregated states. Their chiroptical properties of CD and CPL signals were influenced strongly by the molecular stacking in various states. The self-assembly in mesophase resulted in the best chiroptical properties. The longer alkyl chains contributed to stronger CD and CPL signals. The highest glum value attained 1.6 × 10-2 for sample 2c based on the effective chirality transfer and amplification of liquid-crystalline mesophase.

Study on the hydrodynamic performance of two typical groove liquid film seals considering cavitation

PurposeThe purpose of this paper is to investigate the hydrodynamic performance of liquid film seals with oblique grooves (OGs) and spiral grooves (SGs), considering cavitation, compare and analyze the differences between them.Design/methodology/approachConsidering cavitation effect, the incompressible steady-state Reynolds equation was solved to obtain the sealing performance parameters of the liquid film seal with oblique groove and spiral groove.FindingsThe hydrodynamic performance of oblique groove seal (OGS) and spiral groove seal (SGS) shows a similar trend with the change of operating parameters. When the groove angle is less than 20°, the load-carrying capacity of SGS is better than that of OGS, while when the groove angle continues to increase, the hydrodynamic performance of OGS is slightly better than that of SGS, and more suitable for use under small differential pressure and high speed.Originality/valueThe hydrodynamic characteristics of liquid film seals with oblique grooves and spiral grooves considering cavitation effect were studied, which provides a theoretical reference for the application of oblique groove seal.

Ligand-Assistant Iced Photocatalytic Reduction to Synthesize Atomically Dispersed Cu Implanted Metal-Organic Frameworks for Photo-Enhanced Uranium Extraction from Seawater.

Uranium extraction from natural seawater is one of the most promising routes to address the shortage of uranium resources. By combination of ligand complexation and photocatalytic reduction, porous framework-based photocatalysts have been widely applied to uranium enrichment. However, their practical applicability is limited by poor photocatalytic activity and low adsorption capacity. Herein, atomically dispersed Cu implanted UiO-66-NH2 (Cu SA@UiO-66-NH2 ) photocatalysts are prepared via ligand-assistant iced photocatalytic reduction route. N-Cu-N moiety acts as an effective electron acceptor to potentially facilitate charge transfer kinetics. By contrast, there exist Cu sub-nanometer clusters by the typical liquid phase photoreduction, resulting in a relatively low photocatalytic activity. Cu SA@UiO-66-NH2 adsorbents exhibit superior antibacterial ability and improved photoreduction conversion of the adsorbed U(VI) to insoluble U(IV), leading to a high uranium sorption capacity of 9.16mg-U/g-Ads from natural seawater. This study provides new insight for enhancing uranium uptake by designing SA-mediated MOF photocatalysts.

Liquid crystalline matrix-induced viscoelastic mechanical stimulation modulates activation and phenotypes of macrophage.

Accumulating evidence indicates that the mechanical microenvironment exerts profound influences on inflammation and immune modulation, which are likely to be key factors in successful tissue regeneration. The elastic modulus (Em) of the matrix may be a useful adjustable property to control macrophage activation and the overall inflammatory response. This study constituted a series of Em-tunable liquid crystalline cell model (HpCEs) resembling the viscoelastic characteristic of ECM and explored how mechanical microenvironment induced by liquid crystalline soft matter matrix affected macrophage activation and phenotypes. We have shown that HpCEs prepared in this work exhibited typical cholesteric liquid crystal phase and distinct viscoelastic rheological characteristics. All liquid crystalline HpCE matrices facilitated macrophages growth and maintained cell activity. Macrophages in lower-Em HpCE matrices were more likely to polarize toward the pro-inflammatory M1 phenotype. Conversely, the higher-Em HpCEs induced macrophages into an elongated shape and upregulated M2-related markers. Furthermore, the higher-Em HpCEs (HpCE-O1, HpCE-H2, HpCE-H1) could coax sequential polarization states of RAW264.7 from a classically activated "M1" state toward alternatively activated "M2" state in middle and later stage of cell culture (within 3-7 days in this work), suggesting that the HpCE-based strategies could manipulate the local immune microenvironment and promote the dominance of the pro-inflammatory signals in early stages, while M2 macrophages in later stages. The liquid crystalline soft mode fabricated in this work maybe offer a new design guideline for in vitro cell models and applications.

Pyrolytic characteristics, kinetics, thermodynamics, volatile products and chemical reactions of micron polypropylene infiltrated with kerosene

The pyrolysis of polymers infiltrated with combustible liquids is one common behavior in the fire accidents resulted by the leakage and overflow of combustible liquids over polymers. The present study may provide a theoretical basis and guidance for the prediction of fire development, the selection or design of fire detection and the design of ventilation and fire extinguishing systems. In the present study, the thermal decomposition behaviors, kinetics, thermodynamics, volatiles and chemical reactions of micron polypropylene (typical polymer) infiltrated with kerosene (typical combustible liquid) are investigated. It is concluded that the thermal decomposition process of micron PP with kerosene can be divided into two stages, and all stages can be considered as one-step reaction. As the kerosene content increases, the average and peak reaction rates of the first stage increase, while they decrease for the second stage and the whole process. As the heating rate increases, the average and peak reaction rates of the whole process decrease. In addition, increasing the heating rate or kerosene content may result in better combustion performance compared with that of pure PP. The calculated average activation energy, pre-exponential factor and global reaction model of the second stage can well predict the thermal decomposition behaviors of this stage. Thermodynamic analysis shows that the thermal decomposition of micron PP with kerosene is an endothermic and non-spontaneous reaction. The main volatile products contain olefins, alkynes, alkanes, hydrogen, carbon dioxide, carbon monoxide and aromatic compounds. The possible chemical reactions generating the above-mentioned products are deduced.

Extraction of rubidium ion from brine solutions by dicyclohexano-18-crown-6 / ionic liquid system

Abstract Separation among rubidium and potassium ions from salt lake brines remains challenging. In this work, a typical room temperature ionic liquid 1-ethyl-3-metyhlimidazaolium bis(trifluoromethylsulfonyl)imide ([C2mim+][NTf2 –]) was used as diluent and synergistic extractant, dicyclohexano-18-crown-6 (DCH18C6) was used as extractant to extract rubidium ions from brine solutions which contain high concentrations of potassium ions was investigated. Under the optimal conditions, the single extraction efficiency of rubidium ions was up 93.63%. The thermodynamic parameters of the rubidium ion extraction were obtained. Based on the slope analysis method, the extracted species in the organic phase were ascertained as 1:1 complex. UV-visible has been performed to investigate the ion concentration of ionic liquid before and after the interaction of metal ions and ligands. Rubidium ions in [Rb · DCH18C6]+ complex were stripped by 2.5 mol · L–1 NH4NO3. The extraction system offers high efficiency, simplicity and environmentally friendly application prospect to separate rubidium from brine solutions.

Understanding mesophase pitch from a lyotropic liquid crystalline perspective

This review explores recent research regarding mesophase pitch (MP). Spinnable mesophase pitch (SMP) was used as a model pitch for MP in all experiments. We explain some phenomenological results of the lyotropic liquid crystalline properties of the SMP, which show that the MP behaves as a typical lyotropic liquid crystal. The mesogenic and solvent components of SMP are defined. We define the threshold concentration (TC) as the minimum amount of mesogenic component necessary for SMP to achieve 100 vol% anisotropy. We also report the TCs of various SMPs and discuss the effects of the solvent component. Concerning the identity of the mesogenic component, we discuss quantitative correlations between the size of the layered molecular stacking units and the anisotropic content of the SMP. Research has shown that a layered molecular stacking unit larger than a specific size corresponds to the mesogenic component of the MP. We discuss a novel method for the manufacture of SMPs using our understanding of MP as a lyotropic liquid crystal, which comprises thermal mixing of optimal amounts of the mesogenic and solvent components that were prepared separately under different conditions. This method enables the properties of each component to be optimized without involving a costly hydrogenation process. Finally, we discuss how this approach can be used to increase SMP yield by modifying the contents of the anisotropic mesogenic and solvent components.

Shaping 1,2,4-Triazolium Fluorinated Ionic Liquid Crystals

The synthesis and thermotropic behaviour of some di-alkyloxy-phenyl-1,2,4-triazolium trifluoromethane-sulfonate salts bearing a seven-carbon atom perfluoroalkyl chain on the cation is herein described. The fluorinated salts presenting a 1,2,4-triazole as a core and differing in the length of two alkyloxy chains on the phenyl ring demonstrated a typical liquid crystalline behaviour. The mesomorphic properties of this set of salts were studied by differential scanning calorimetry and polarized optical microscopy. The thermotropic properties are discussed on the grounds of the tuneable structures of the salts. The results showed the existence of a monotropic, columnar, liquid crystalline phase for the salts tested. An increase in the temperature mesophase range and the presence of two enantiotropic mesophases for the sixteen-atom alkyloxy chain salt can be observed by increasing the length of the alkyloxy chain on the phenyl ring.

Spin column-based peptide fractionation alternatives for streamlined tandem mass tag (SL-TMT) sample processing

Fractionation is essential to achieving deep proteome coverage for sample multiplexing experiments where currently up to 18 samples can be analyzed concurrently. However, peptide fractionation (i.e., upstream of LC-MS/MS analysis) with a liquid chromatography system constrains sample processing as only a single sample can be fractionated at once. Here, we highlight the use of spin column-based methods which permit multiple multiplexed samples to be fractionated simultaneously. These methods require only a centrifuge and eliminate the need for a dedicated liquid chromatography system. We investigate peptide fractionation with strong anion exchange (SAX) and high-pH reversed phase (HPRP) spin columns, as well as a combination of both. In two separate experiments, we acquired deep proteome coverage (>8000 quantified proteins), while starting with <25 μg of protein per channel. Our datasets showcase the proteome alterations in two human cell lines resulting from treatment with inhibitors acting on the ubiquitin-proteasome system. We recommend this spin column-based peptide fractionation strategy for high-throughput screening applications or whenever a liquid chromatograph is not readily available. SignificanceFractionation is a means to achieve deep proteome coverage for global proteomics analysis. Typical liquid chromatography systems may be a prohibitive expense for many laboratories. Here, we investigate prefractionation with strong anion exchange (SAX) and high-pH reversed phase (HPRP) spin columns, as well as a combination of both, as peptide fractionation methods. These spin columns have advantages over liquid chromatography systems, which include relative affordability, higher throughput capability, no carry over, and fewer potential instrument-related malfunctions. In two separate experiments, we acquired deep proteome coverage (>8000 quantified proteins), thereby showing the utility of each or a combination of both spin columns for global proteome analysis.

Effect of Prandtl number on the flow instabilities in thermocapillary liquid bridges between two coaxial disks with different radii

The effect of Prandtl number on the instability of thermocapillary liquid bridges has been extensively studied, but the vast majority of efforts were put into typical cylindrical liquid bridge between two equal ends. The crystal growth practices have the propensity to form liquid bridges between unequal disks, thus the dependence of instability patterns and underlying mechanisms on the radius ratio is crucial but remains unclear. By fixing the radius ratio at Γr=0.5, we systematically explore the effects of Prandtl number and heating strategy, namely the upper heating and the bottom heating settings, on flow instabilities in thermocapillary liquid bridges between coaxial disks with different radii under microgravity through linear stability analysis based on spectral element method. In contrast to typical cylindrical liquid bridge (Γr=1), the present analysis indicates that the instability is always an oscillatory bifurcation even for small Prandtl number Pr=0.001 in the bottom heating scenario. What's more, the instability remains a stationary bifurcation and the critical Marangoni number experiences significant increase with the rise of Pr in the region of 0.001≤Pr≤1.2 for the upper heating situation. For all liquid bridges, the energy analysis results show that the instability under different Prandtl numbers can be roughly divided into three types.

Atmospheric fate of typical liquid crystal monomers in the tropospheric gas, liquid, and granular phases

Mineral aerosol particles significantly impact environmental risk prediction of liquid crystal monomers (LCMs). In this work, we investigated the reaction mechanisms and kinetics of three typical LCMs (4-cyano-3,5-difluorophenyl 4-ethylbenzoate (CEB-2F), 4-cyano-3-fluorophenyl 4-ethylbenzoate (CEB-F), and 4-cyanophenyl 4-ethylbenzoate (CEB)) with ozone (O3) in the atmospheric gas, liquid, and particle phases employing density functional theory (DFT). Here, O3 is prone to add to the benzene ring without F atom(s) in the selected LCMs. The ozonolysis products are aldehydes, carboxylic acids, epoxides, and unsaturated hydrocarbons containing aromatic rings. Those products undergo secondary ozonolysis to generate small molecular compounds such as glyoxal, which is beneficial for generating secondary organic aerosol (SOA). Titanium dioxide (TiO2), an essential component of mineral aerosol particles, has good adsorption properties for LCMs; however, it slightly reduces the reactivity with O3. At 298 K, the reaction rate constant of the selected LCMs reacting with O3 in the gas and atmospheric liquid phases is (2.74‒5.53) × 10−24 cm3/(mol·sec) and 5.58 × 10−3‒39.1 L/(mol·sec), while CEB-2F reacting with O3 on (TiO2)6 cluster is 1.84 × 10−24 cm3/(mol·sec). The existence of TiO2 clusters increases the persistence and long-distance transportability of LCMs, which enlarges the contaminated area of LCMs.

Extraction Behavior of Lanthanoids(III) with Bis(2-ethylhexyl)phosphoric Acid into Ionic Liquid 1-Butyl-3-methylimidazolium Bis(trifluoromethanesulfonyl)imide

The extraction behavior of 14 trivalent lanthanoids (Lns) with bis(2-ethylhexyl)phosphoric acid (HR) into a typical hydrophobic ionic liquid (IL), 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, was investigated. The extraction is so slow that a shaking time of more than 36 hours is needed to reach extraction equilibrium. Compared to the extraction system using toluene as an extraction solvent, the IL extraction system has higher extraction ability for all Lns and higher selectivity for some couples of Lns (e.g., Ce/La and Tb/Gd). The dependences of the distribution ratio on the aqueous pH and the HR concentration suggest that the main extracted species are neutral LnR3(HR)3 for light and middle Lns and Tb, but anionic LnR4(HR)2– and LnR5(HR)2– for heavy Lns (except for Tb). The addition of 1-octanol as a phase stabilizer decreases the extractability of Lns, which can be explained in terms of interaction between 1-octanol and HR dimer.

Role of inorganic layers on polysulfide decomposition at sodium-metal anode surfaces for room temperature Na/S batteries.

Sodium metal is a promising anode material for room-temperature sodium sulfur batteries. Due to its high reactivity, typical liquid electrolytes (e.g. carbonate-based solvents and a Na salt) can undergo reduction to form a solid electrolyte interphase (SEI) layer, with inorganic components such as Na2CO3, Na2O, and NaOH, covering the anode surface along with other SEI organic products. One of the challenges is to understand the effect of the SEI film on the decomposition of soluble sodium polysulfide molecules (e.g., Na2S8) upon shuttling from the cathode to anode during battery cycling. Here, we use ab initio molecular dynamics (AIMD) simulations to study the role of an inorganic SEI used as a model passivation layer in polysulfide decomposition. Compared to other film chemistries, it is found that the Na2CO3 film can suppress decomposition with the slowest reduction rate and the smallest amount of charge transfer towards Na2S8. The Na2CO3 film can maintain its structural properties during the simulations. In contrast, Na2O and NaOH allow some decomposed polysulfide fragments to be inserted into the SEI layer. Moreover, the decomposition of Na2S8 on both Na2O and NaOH SEI layers is more reactive with more charge transfer to Na2S8 when compared to that of Na2CO3. Thus, the ability of the SEI to suppress polysulfide decomposition is in the order: Na2CO3 > NaOH ∼ Na2O. Analyses of the density of states reveal that the Na2S8 molecule receives electrons from the Na metal directly in the presence of n-type semiconductor films of Na2CO3 and NaOH, while the charge migration behavior is different in a p-type semiconductor Na2O with the SEI film donating its electrons to the polysulfide solely. Thus, this work adds new insights into charge transfer behavior of inorganic thin film SEIs that could be present at the initial stages of SEI formation.

Interfacial Instability-Induced (3I) Adhesives through "Mediator" Solvent Diffusion for Robust Underoil Adhesion.

Underoil adhesives are intensively needed in case of oil spill caused by pipeline rupture, but remain a challenge owing to the obstruction of oil layer or their swelling in oil. Herein, a general solvent diffusion principle is demonstrated by introducing dual-soluble "mediator" solvents to develop a new type of interfacial instability-induced (3I) adhesives, achieving effective underoil adhesion on various substrates and blocking the oil leakage within seconds. Microscopic characterization reveals a fast and dynamic solvent exchange process that destroys the oil layer by liquid-liquid interfacial diffusion between the "mediator" solvent and oil, enabling 3I adhesives to contact the solid surfaces directly. The principle of interfacial instability-induced liquid replacement is quite different from typical immiscible liquid replacement and is not restricted by the surface tension of solvents, surface energy, and roughness of solid surfaces, successfully directing the construction of a series of effective 3I adhesives with commercially available feedstocks. This study provides a unique clue for the design of next-generation adhesives in complex environments.

Characterization of liquid film distribution and sub-flow regimes of annular flow in helically coiled tubes using ring island array sensor

The distribution of liquid film thickness in helically coiled tubes (HCTs) directly affects the heat transfer performance of the annular flow region. However, due to the limitation of measurement technology, accurate measurement data of liquid film thickness in HCTs is very rare. In this paper, a non-invasive contact liquid film thickness sensor (ring island array sensor) is successfully developed to obtain the refined three-dimensional spatial-temporal distribution data of liquid film thickness in HCTs. According to the results, four typical liquid film flow regimes are defined based on the circumferential position of the thicker liquid film appearing in the tube wall, i.e., the bottom distribution (BD) dominated by liquid phase gravity force, the outside distribution (OD) dominated by liquid phase centrifugal force, the inside distribution (ID) dominated by gas centrifugal force and the inside-outside distribution (IOD) dominated by the secondary flow. These circumferential distributions of liquid film thickness are mainly affected by the HCT structure (e.g., coil diameter and coil pitch) and superficial gas-liquid velocities. Based on the modified Dean number De* and the modified Lockhart-Martinelli parameter X*, which consider the influence of HCT structures, fluid properties and operating parameters, a general sub-flow regime map of annular flow is proposed. The prediction models of transition boundaries of different liquid film flow regimes are also established and verified with present and available data in the literature.

Emission-Driven Hybrid Rocket Engine Optimization for Small Launchers

Hybrid rocket engines are a green alternative to solid rocket motors and may represent a low-cost alternative to kerosene fueled rockets, while granting performance and control features similar to that of typical storable liquid rocket engines. In this work, the design of a three-stage hybrid launcher is optimized by means of a coupled procedure: an evolutionary algorithm optimizes the engine design, whereas an indirect optimization method optimizes the corresponding ascent trajectory. The trajectory integration also provides the vertical emission profiles required for the evaluation of the environmental impact of the launch. The propellants are a paraffin-based wax and liquid oxygen. The vehicle is launched from the ground and uses an electric turbo pump feed system. The initial mass is given (5000 kg) and the insertion of the payload into a 600-km circular, and polar orbit is considered as a reference mission. Clusters of similar hybrid rocket engines, with only few differences, are employed in all stages to reduce the development and operational costs of the launcher. Optimization is carried out with the aim of maximizing the payload mass and then minimizing the overall environmental impact of the launch. The results show that satisfactory performance is achievable also considering rocket polluting emissions: the carbon footprint of the launch can be reduced by one fourth at the cost of a 5-kg payload mass reduction.

Hydraulic design optimization of spherical header for future fast reactors of India

The liquid sodium as coolant in a typical pool type Liquid Metal cooled Fast Breeder Reactor (LMFBR), flows through primary sodium pump, spherical header and finally enters the grid plate, which acts as an inlet plenum to heat-generating sub-assemblies. The reduction of pressure drop in primary circuit would reduce the operating cost of the system. Spherical header, a vital component in primary circuit suffers major flow non-uniformities resulting in higher pressure drop. Reduction of the pressure drop by uniformization of sodium flow in spherical header is considered. To this end, a 3D computational fluid dynamics (CFD) analysis is carried out to investigate the hydrodynamics of flow, inside the spherical header. Towards this a relationship between pressure loss coefficient and geometrical dimensions, viz., diameter and height of the cone, inside the header are established in order to minimize the pressure drop. The variation of pressure loss coefficient is estimated for header without and with the internals. The static pressure loss coefficient inside the spherical header without an internal cone is found to be 5.59. With a suitable and optimized geometrical dimension of the cone as internal flow guiding device, the loss coefficient is reduced to 0.53. The loss coefficient predicted for the spherical header is validated against the experimental estimates. Consequently, the simplified design of the flow guiding device is achieved by removing baffles.

SEISMIC EVALUATION OF FLEXIBLE STEEL WATER STORAGE TANKS

Cylindrical steel liquid storage tanks are widely used for water supply and industrial chemicals. The seismic response of these tanks differs from buildings as it stores liquid with different hydrodynamic characteristics. Steel tanks can be exposed to severe damages during earthquakes such as elephant’s foot buckling, diamond shape buckling, roof damage and failure of anchor bolts. This research investigates the seismic behavior of flexible steel water storage tanks using an analytical method. A series of parametric analyses are conducted for a typical liquid storage tank with different geometry properties and soil conditions. The effects of storage tank height, wall thickness, and subsoil type are investigated and their effects on the seismic response of the tank are evaluated and discussed. The results indicate that the soil type (representing shear wave velocity and shear modulus of the soil) has a profound impact on the base shear, overturning moment and hoop stress in the flexible tanks.

Thermoacoustic Soret separation.

In a fluid mixture in a channel with an axial time-averaged temperature gradient, high-amplitude oscillating flow can greatly increase the axial flux of thermal diffusion (Soret) separation of the components of the mixture. The enhancement occurs when the oscillating lateral temperature gradient greatly exceeds the axial gradient, causing a large oscillating concentration that can be favorably time-phased with the oscillating flow. This process can occur even with a negligible pressure oscillation or with a negligible temperature response to pressure, as is the case in most liquid solutions. The thermal boundary condition imposed by realistic solids on thermoacoustic liquids is imperfect, adding mathematical complications that are absent for typical gases, for which the solid surface is temporally isothermal. Compared with gas mixtures, the high Lewis number in typical liquid solutions reduces the separation flux associated with the time-averaged temperature gradient, but it also reduces the remixing associated with the time-averaged mole-fraction gradient. For large enough channels, the second-law separation efficiency is only slightly reduced from that of steady liquid Soret separation.