High Liquid Research Articles

Linear solvent strength model on porous graphitic carbon stationary phase using high temperature liquid chromatographic method for allopurinol related substances analysis

A high-performance liquid chromatography (HPLC) method was developed for the analysis of Allopurinol and its Ph.Eur. impurities using a porous graphitic carbon (PGC) stationary phase. Retention behavior of solutes was studied across a wide temperature range (30–90 °C) and various gradient times (5–20 min). Analysis of the data revealed distinct retention mechanisms between reversed-phase and PGC phases. However, it was proved that the retention of Allopurinol and its Ph.Eur. impurities on PGC stationary phase can be effectively modeled using the linear solvent strength (LSS) theory. This allows for the utilization of LSS-based method development software to optimize methods under these conditions. By using commercial chromatographic modeling software, separation of Allopurinol and Ph.Eur. impurities was optimized within a large design space. At the optimized operating conditions (pH = 2.0, tG = 6 min, T = 60 °C), all solutes were separated within 6 min with baseline resolution. Comparison between predicted and experimentally measured chromatograms further confirmed the applicability of LSS theory in developing analytical methods for PGC-based HPLC systems. The presented approach offers a general framework for method development on PGC phases.

Experimental study on the upward annular two-phase flow of nitrogen and ethanol aqueous solutions with different concentrations

Vertical upward annular flow experiments of nitrogen gas and ethanol aqueous solutions with volume fractions of 30 %, 60 %, and 95 % under 0.2 MPa were conducted. The characteristics of the liquid film including base, average, and maximum film thickness and height, velocity, and frequency of disturbance waves were obtained and studied based on the constant electric current method in a 5 mm inner diameter polycarbonate tube. The flow behavior was observed using a high-speed camera simultaneously. It is found that a large number of bubbles in the liquid film is critical to these characteristics. A connection between ethanol concentration and bubbles in the liquid film is found and interpreted by considering bubble stability which arises from the dynamic rise in surface tension. Our experimental investigation suggests that the effect of bubbles in the liquid film on the flow characteristics is not negligible in such annular flows under high liquid flow rates and bubble stability should be considered for annular flows employing solutions consisting of two or more components with large differences in surface tension.

Rotating heat pipe model based on lumped parameter method

On the basis of many theoretical studies about rotating heat pipes, a simplified mathematical model is established based on the lumped parameter method, ignoring the temperature difference inside each section of the heat pipe is ignored, and comparing the calculated results with the experimental data. It is identified that this model has a good applicability at high speeds and low liquid filling rates, and effectively reduces the amount of calculation, which is of practical significance to the engineering application of rotating heat pipes.

Effects of liquid viscosity and air injection rate on air invasion in a highly compacted granular material

Using laboratory experiments on a network scale together with numerical simulations on a granular scale, we investigate the displacement process as air invades a highly compacted granular material. Experiments in a vertically placed Hell-Shaw cell reveal a non-monotonic behavior of branching formation as air injection rate Q increases from 0.1 to 50 ml min–1 when the liquid viscosity is less than 22.5 mPa s. In the low-injection-rate region where Q < 1 ml min–1, fractures grow in random directions, and the number of branches increases as the air injection rate decreases. However, after the transition to the high-injection-rate region where Q≥ 1 ml min–1, the number of branches increases with increasing air injection rate. At a given air injection rate, increasing the liquid viscosity from 1.01 to 219 mPa s leads to an increasingly concentrated air flow. The numerical simulations exhibit good agreement with the experimental results. More importantly, they shed light on the physics underlying the growth of the fractures by capturing the distribution of the magnitude of velocity, as well as computing the inter-grain force chains in the granular material. The simulations suggest that a high liquid viscosity concentrates the velocity field and force chains and reduces the speeds and inter-grain forces of the grains adjacent to fractures, while a higher air injection rate increases the grain speeds and inter-grain forces. In addition, the distribution of the forces chains behaviors non-monotonically as the air injection rate decreases, which explains the non-monotonic behavior of branching formation observed in the experiments.

Dynamic simulation of CHL at SNS

A dynamic simulation model of Central Helium Liquefier (CHL) has been developed by the process simulation software; EcosimPro™. CHL consists of 4 K and 2 K cold boxes to sustain the operation of LINear ACcelerator (LINAC) which is composed of Superconducting Radio Frequency (SRF) cavities installed in the Cryomodules. 4 K cold box is a modified Claude cycle refrigerator, having LN2 precooler with two Brayton Cycle turbines, followed by the series connected Turbines (Tu3 and Tu4), and a Supercritical Helium (SHe) turbine (Tu5) for high thermodynamic efficiency. The product of 125 g/s of SHe is subcooled at the LHe immersed Heat eXchanger (HX) before supplying to Cryomodules, which has its own precooled HX for He II vapor vs. SHe, to have high liquid yield for He II at 2.1 K. Four series connected Cold Compressors (CCs) keep the LINAC pressure at 0.04 bar for the proton beam acceleration. The paper discusses the modeling of CHL, including four CCs. The benchmark of the model against a design specification of CHL and the validation of CC model is also described in detail.

Effect of Mixture Composition on the Photophysics of Indoline Dyes in Imidazolium Ionic Liquid-Molecular Solvent Mixtures: A Femtosecond Transient Absorption Study.

We conducted a study on the photophysics of three indoline dyes, D102, D149, and D205, in binary mixtures of ionic liquids (IL) and polar aprotic molecular solvents (MS). Specifically, we examined the behavior of these dyes in IL-MS mixtures containing four different imidazolium-based ILs and three different polar aprotic MSs. Our investigation involved several techniques, including stationary absorption and emission measurements, as well as femtosecond transient absorption (TA) spectroscopy. Through our analysis, we discovered a peculiar behavior of several photophysical properties at low IL mole fractions (0 < XIL < 0.2). Indeed, in this range of mixture composition, the absorption maximum wavelength decreases noticeably, while the emission maximum wavelength and the Stokes shift, expressed in wavenumbers, reach a maximum. while a minimum occurs in the relative quantum yield and the excited state lifetime. These results indicate that the solvation of dye undergoes a large change in this range of mixture composition. We found that, at high ionic liquid content, the excited relaxation times are correlated with the high viscosity, while at low content, it is the polarity of the solvent that influences the behavior of the excited relaxation times. At a mixture composition of around 0.10, the behavior of the photophysical properties of the studied IL-MS mixtures indicates a crossover between situations where the solvation is dominated by that of ions and that dominated by the solvent.

Study on H3PO4-activated carbon catalytic co-pyrolysis of bamboo and LDPE to poly-generation syngas and aromatics at low temperature

Biomass-derived carbon activated by H3PO4 was adopted to catalytic co-pyrolysis of bamboo and low-density polyethylene (LDPE) to produce syngas and aromatics on a fixed bed reactor. Effects of LDPE ratio in the feedstock, catalytic co-pyrolysis temperature and ratio of catalyst to feedstock on the yields and compositions of the products were investigated. The increase of LDPE ratio in liquid first improved and then reduced the relative content of aromatics, while it showed a positive effect on the yield and the H2/CO ratio of gas. 500℃ was an optimum temperature, under which the relative content of aromatics in liquid kept higher, meanwhile, avoided the undesirable polymerization reactions of monocyclic aromatics. At the same time, the content of H2 in gas reached a maximum (59.3%), which was in favor of poly-generation. H3PO4-activated carbon catalyst (H3PO4-ACC) with abundant functional groups on surface catalyzed cracking, hydrodeoxygenation, cyclization and aromatization reactions so as to facilitate the generation of aromatics. Non-condensable gas was dry reformed on P-ACC at the expense of CO2, CH4 and CO to generate char and H2. When the reaction condition was at a LDPE ratio of 50%, a catalyst/feedstock ratio of 2:1 and at 500℃, the relative content of aromatics in liqiud was 81.65% and the proportion of syngas component in gas was 79.73%. The volume ratio of H2/CO approached to 3:1 in gas under this condition. H3PO4-ACC catalytic co-pyrolysis of bamboo and LDPE could obtain high quality gas and liquid products at a relative low reaction temperature, which provided a new research idea on high-value application of biomass and waste plastics.

Design of liquid level detection circuit based on sampling probe structure capacitance.

Liquid level detection system is an essential core functional component of automatic clinical medical testing instrument. The conventional liquid level detection method has low detection accuracy and sensitivity, and may have the problem of false detection, which may lead to the inaccurate test results. This paper presents a high sensitivity liquid level detection system based on the principle of variable capacitance. When the sampling probe contacts the liquid level, the probe capacitance will change. The liquid level detection circuit board judges whether the probe contacts the liquid level by sensing the change of probe capacitance. When judging the liquid level signal, the combination of slope detection and amplitude detection is used. The liquid level detection circuit board takes the phase-locked loop(PLL) circuit as the center to detect the change of the capacitance. The reference signal of the PLL is set as a square wave of 375kHz. The double tube probe is used as a part of the tuning capacitor of the voltage controlled oscillator to control the frequency of the output signal, which can realize the rapid phase locking. The experimental results show that the system has accurate detection results, high sensitivity, stable and reliable operation, good dynamic response performance in the case of large and small liquid volume. Compared with other liquid level detection methods based on machine vision, ultrasonic, optics and so on, the proposed liquid level detection system has simpler structure and lower cost, it can avoid the problems of collision, carryover contamination and empty suction by controlling the depth of sampling needle inserted into liquid.

Wet torrefaction of biomass waste into high quality hydrochar and value-added liquid products using different zeolite catalysts

Wet torrefaction (WT) proves to be a highly efficient pretreatment method for biomass waste, resulting in the production of hydrochar and valuable liquid products. In this study, a groundbreaking chemocatalytic approach is introduced, employing various zeolite catalysts (H-ZSM-5, H-Beta, H–Y, H-USY, and H-Mordenite) in a batch reactor under a nitrogen atmosphere. This method enables the simultaneous one-pot production of levulinic acid (LA) and/or bio-ethanol during the WT process of wood cellulose pulp residue (WCPR), ultimately yielding high-quality solid fuel. The WT process involves at 220 and 260 °C, H2O/WCPR = 10, and torrefaction time at 15, 30 and 60 min. The study identifies that at 220 °C and 15 min, as the optimal temperature and time, for bio-ethanol production, achieving a selectivity of 59.0 % with the H–Y catalyst, while the highest amount of bio-ethanol (75.6 %) was detected in presence of H-USY zeolite at 260 °C after 60 min. In addition, it was found the formation of relatively high amount of LA (62.0 %) at 220 °C after 60 min but using the H-ZSM-5 catalyst. For the WT + Mordenite sample (220 °C, 60 min), the highest carbon content of 71.5 % is achieved, resulting in the higher heating value (HHV) of 27.3 MJ/kg, an enhancement factor of 1.36, and carbon enrichment of 1.48, with the sequence of element removal during WT prioritized as DO > DH > DC and the weight loss of 68 %. Finally, the reaction mechanism was proposed to elucidate the formation of liquid products after WT of WCPR with participation of zeolite catalysts. The main pathway involving the direct conversion of cellulose into hydroxyacetone, followed by the subsequent generation of ethanol through the C–C cleavage of hydroxyacetone while LA formed via well-known route which includes cellulose hydrolysis to form glucose, conversion to 5-HMF and the subsequent transformation of 5-HMF into LA.

Demonstration of Mixer-Settlers Runs for Separation of Uranium and Neptunium by TBP Vis-a-Vis DHOA Under a Legacy Waste Condition

ABSTRACT Separation of neptunium from an acidic feed containing 0.063 mol/L uranium in 3 mol/L HNO3 was demonstrated in counter-current extraction in mixer-settlers with TBP (tri-n-butyl phosphate) and DHOA (N,N’-dihexyl octanamide) as the organic extractants. With a feed solution of 0.063 mol/L uranium (in the absence of neptunium) and at an organic to aqueous phase ratio (O/A) = 1, >99.9% uranium could be extracted into the organic phase in 6 stages with the raffinate containing <10−5 mol/L of uranium. The extraction results with TBP and DHOA were comparable. However, stripping of uranium with 0.01 mol/L HNO3 from the loaded organic phase was better with DHOA vis-a-vis TBP phase. From the DHOA phase, loaded with 0.063 mol/L uranium, the entire metal ion could be stripped in 6 stages at an O/A = 1. However, ca. 17% uranium remained in the TBP phase even after 6 stages of stripping. With these preliminary results, the extraction of neptunium was systematically studied in mixer-settlers from feed containing uranium, and from simulated high level liquid waste. Our results of neptunium extraction in the presence of 0.021 mol/L uranium yielded excellent result. Similarly, the extraction of neptunium from simulated high level liquid waste was also demonstrated with good extraction efficiency.

Tuning of molecular weight and chemical composition of polyols obtained from Poly(ethylene terephthalate) waste recycling through the application of organocatalysts in an upcycling route

High molecular weight liquid polyols were produced from complex Poly (ethylene terephthalate) (PET) waste (low molecular weight PET waste, monolayer compounds, and coloured PET bottles) in one-step synthesis using mild reaction conditions. For the first time, a wide range of upcycled polyols were obtained by modulating the reaction conditions to control the chemical composition and molecular weight, in order to revalorize the same PET waste in different polyols.A new versatile, efficient, selective and sustainable chemical recycling method was developed, employing cheap reagents (ethylene carbonate) and basic organocatalysts, under mild reaction conditions (moderate temperatures and atmospheric pressure). Chemically, the polyols showed a singular composition, consisting of three types of repeating units, two coming from PET and one belonging to the ethylene carbonate ring-opening. Depending on the depolymerisation conditions of the PET waste and the catalyst used, the ratio between these moieties varied considerably, giving rise to a wide portfolio of liquid polyols. In addition, the ability of the organocatalyst to introduce the carbonate unit into the polyol chain was analysed as a function of the number of ethylene carbonate units used.As a proof of concept, these new liquid secondary raw materials served as a starting point for the synthesis of polyurethanes under standard conditions. Ultimately, the final objective of this upcycling process will be the application of a wide range of high-quality polyols as soft segments to produce more sustainable and high-performance polyurethanes (flexible foams, coatings, sealants, adhesives, elastomers).

Functionalizing tandem mass tags for streamlining click-based quantitative chemoproteomics

Mapping the ligandability or potential druggability of all proteins in the human proteome is a central goal of mass spectrometry-based covalent chemoproteomics. Achieving this ambitious objective requires high throughput and high coverage sample preparation and liquid chromatography-tandem mass spectrometry analysis for hundreds to thousands of reactive compounds and chemical probes. Conducting chemoproteomic screens at this scale benefits from technical innovations that achieve increased sample throughput. Here we realize this vision by establishing the silane-based cleavable linkers for isotopically-labeled proteomics-tandem mass tag (sCIP-TMT) proteomic platform, which is distinguished by early sample pooling that increases sample preparation throughput. sCIP-TMT pairs a custom click-compatible sCIP capture reagent that is readily functionalized in high yield with commercially available TMT reagents. Synthesis and benchmarking of a 10-plex set of sCIP-TMT reveal a substantial decrease in sample preparation time together with high coverage and high accuracy quantification. By screening a focused set of four cysteine-reactive electrophiles, we demonstrate the utility of sCIP-TMT for chemoproteomic target hunting, identifying 789 total liganded cysteines. Distinguished by its compatibility with established enrichment and quantification protocols, we expect sCIP-TMT will readily translate to a wide range of covalent chemoproteomic applications.

A novel numerical approach for assessing the gas-liquid flow characteristics in pipelines utilizing a two-fluid model

The accumulation of liquid condensate in the wet gas pipelines gives negative effects on the piping efficiency and flow managements. Accurate prediction of the condensate behavior is of crucial importance in the pipeline engineering. In this study, the one-dimensional two-fluid model with the stratified modeling in its source term is used to describe the gas-liquid kinetic motion along the pipe and the flow fields obtained from the newly proposed numerical approach are utilized to analyze the flow characteristics. Firstly, four cases with varying inlet liquid fractions, outlet pressures, and different meshes are utilized to investigate the gas-liquid steady-state variations along the pipe. The numerical results indicate that the outlet pressure influences the working pressure of the inlet gas-liquid, subsequently altering the equilibrium state and momentum exchange direction near the inlet, resulting in different condensate distributions in the pipeline. In the transient analysis with initial empty pipe, the inlet gas-liquid mainly impacts the pressure wave propagations in pressure spread stage, the gas kinetic motion in gas filling stage and the motion of the dividing interface between different regions in liquid filling stage, which is validated by the proposed numerical approach through comparison with the simulation tool OLGA designed by Schlumberger. Furthermore, when the liquid condensates appear in the initial state, the transition zones have two physical forms between different flow regions, which include the sudden dividing interface due to the high liquid amount carried by the inlet gas and the transition region resulted from the liquid accumulations.

Event-by-event direction reconstruction of solar neutrinos in a high light-yield liquid scintillator

The direction of individual B8 solar neutrinos has been reconstructed using the SNO+ liquid scintillator detector. Prompt, directional Cherenkov light was separated from the slower, isotropic scintillation light using time information, and a maximum likelihood method was used to reconstruct the direction of individual scattered electrons. A clear directional signal was observed, correlated with the solar angle. The observation was aided by a period of low primary fluor concentration that resulted in a slower scintillator decay time. This is the first time that event-by-event direction reconstruction in high light-yield liquid scintillator has been demonstrated in a large-scale detector. Published by the American Physical Society 2024

Molecular dynamics study on relaxation of supercooled liquid water at different cooling rates

The relaxation in supercooled liquids is a phenomena by which the thermodynamic system starts transforming from one state to other after losing its high end thermodynamic properties (i.e. density, potential energy, enthalpy, etc.) with a significant change. Since the relaxation phenomena is quite challenging to observe, specifically near the transition region of liquid water. Hence, the thermodynamic analysis for understanding the relaxation phenomena of liquid water in supercooled region from the high density liquid (HDL) state to low density amorphous (LDA) state are important from both fundamental and as well as applied perspectives. Therefore, we focused our study on performing thermodynamic analysis on the relaxation of super-cooled liquid water by using a monatomic water (mW) potential model with an isothermal-isobaric (NPT) molecular dynamics (MD) simulation technique at zero pressure under different cooling rates. In this work, we examine the relaxation in terms of root mean square (RMS) fluctuation of two and three-body potential energy of the maximum size of four coordinated cluster under different cooling rates. The predicted data over this study shows the independency of the cooling rate, where the relaxation of the liquid state of mW water results in a sharp irreversible drop in potential energy and large fluctuation in two and three body potential energy of the maximum size of four coordinated cluster. Further, we found the relaxation of liquid state of mW water associated with the sharp and continuous increase in the fraction of four coordinated particles as a function of temperature for different cooling rates. The predicted results of this study are consistent with the literature, which helps to understand the relaxation phenomena of mW water and other such thermodynamic systems more significantly.

High sedimentation efficiency and enhanced rare earth recovery in the impurity removal process of rare earth leachate by flocculation system

The main impurity ion in rare earth (RE) leachate are aluminum ions, which can be effectively removed by precipitation in the form of aluminum hydroxides. The flocculent colloidal precipitation formed by aluminum ions has a loose structure and high liquid content, resulting in lower sedimentation efficiency and higher RE loss. The addition of flocculants in the impurity removal process of RE leachate is expected to solve this problem. The cationic polyacrylamide flocculant (CPAM) was screened as the flocculant to accelerate the sedimentation of the impurity removal process as well as to effectively improve the recovery of RE. The effects of CPAM concentration, dosage, stirring rate and stirring time on the flocculation process was investigated. The optimal flocculation effect could be obtained under conditions of dosage of 0.5 mL, concentration of 0.1%, stirring speed of 700 r/min and stirring time of 2 min. Under this condition, RE recovery efficiency was 97%, Al removal efficiency was 96%, and the sedimentation time of the flocs was 20 min. Compared with absence of flocculants in this process, Al removal efficiency remained almost unchanged, while RE recovery efficiency and the sedimentation time of flocs increased by 4% and shortened by 40 min, respectively. The flocculation mechanism was discussed by the theory of two-dimensional fractal dimension, and it was found that the flocculation was mainly based on the combined effect of bridge flocculation and electrical neutralization.

Upper limit estimate to wellhead flowing pressure and applicable gas production for a downhole throttling technique in high-pressure–high-temperature gas wells

In recent years, China has explored and exploited several high-pressure deep gas fields. Normally, high-pressure gas wells are gathered and processed through multichoke manifolds on well sites, creating hazards such as high wellhead flowing pressure (Pt) and high risk for on-site operation personnel. Moreover, downhole chokes have been used in place of surface chokes. In doing this, the Joule–Thomson (JT) effect is geothermally regulated, alleviating the formation of hydrates in surface facilities. However, its applicability to high-pressure gas wells is less explored. In an effort to guide its use, the objective of this study is to set selection criteria in terms of the allowable wellhead Pt and gas flow rate. First, isenthalpic lines are separately estimated for dry gas and high liquid hydrocarbon (LHC) content gas condensate at various inlet temperatures with the use of commercial software. Next, by analysis of the resulting isenthalpic curves, several results are obtained on the JT inversion curves and throttling process through a choke. Third, building on these insights, a method for projecting the maximum Pt is presented, leading to a value of 52.5 MPa. Finally, multiparameter models are separately run for two deep gas wells (8100 m and 5000 m), reinforcing the result of the pressure upper limit while maintaining a maximum daily gas production of 14 E4 m3. Both upper limits with a maximum Pt of 52.5 MPa and daily gas production of 14 E4 m3 are corroborated with field data records. These findings are vital to the selection of a viable high-pressure gas well for applying the downhole throttling technique.

Profiling of organosulfur compounds and amino acids in novel variety of Allium sativum (Hisar garlic 17) by HR-LCMS-QTOF

Over the past few years, the biological properties of garlic have been utilized as an attractive natural alternative to many therapeutic drugs. The biological effects of garlic have been ascribed to organosulfur compounds, secondary metabolites derived from amino acids. The present study aimed to investigate the extracts of a novel garlic variety (Hisar garlic 17) after processing it as fresh, dry, heated, and aged in different solvents and then analyzed with highly sensitive and rapid technique i.e., High resolution liquid chromatograph mass spectrometer quadrupole time of flight (HR-LCMS-QTOF) Mass spectrometer to study the amino acids and organosulfur compounds. 47 amino acids and 11 organosulfur compounds were detected out of which 8 organosulfur compounds were found as secondary metabolites of amino acids. Among the 22 crucial α-amino acids, garlic extracts revealed the presence of 18 amino acids, either in their native state or associated with various complex compounds. The study reported major organosulfur compounds, including Alliin, S-allyl cysteine, S-methyl cysteine, N-gamma-Glutamyl-S-allylcysteine, and 2-Propenyl 1-(2- propenylsulfinyl)propyl disulfide. This study demonstrated that HG17 garlic is abundant in amino acids and organosulfur compounds, suggesting its potential utilization as a supplement in nutraceuticals.

Flow boiling of liquid nitrogen in a horizontal macro-tube at low pressure: Part Ⅱ – Heat transfer characteristics

Nitrogen is the most important cryogen in superconductivity. This study investigates the heat transfer characteristics of flow boiling in a horizontal macro-tube with an inner diameter of 10 mm, particularly focusing on flow boiling at negative gauge pressure. The experiments cover the following ranges: inlet pressure from −31.0 to 2.5 kPa, mass flux from 27.0 to 71.3 kg/(m2·s), and heat flux from 0 to 28.68 kW/m2. The effects of operating parameters on the heat transfer coefficient (HTC) are examined, and the HTC data are compared with the predicted value from four correlations. At the bottom wall, the HTC distribution exhibits a “two-peak” shape. The primary peak is dominated by nucleate boiling in bubbly, plug, and slug flow with low vapor quality, while the secondary peak is dominated by convective evaporation with higher vapor quality. These two regions are roughly divided by the vapor quality of 0.3 to 0.4. In stratified flow, the HTC at the top wall is generally lower than that at the bottom. The HTC increases as the pressure decreases, particularly in the convective evaporation region. This is attributed to the high liquid–vapor density ratio, extensive thermal conductivity, and substantial surface tension at lower pressure. The effect of heat flux or mass flux on the HTC at the bottom wall differs between the nucleate boiling and convective evaporation regions. Increasing the heat flux improves the HTC where nucleate boiling dominates, while increasing the mass flux significantly improves convective evaporation, especially at higher heat flux. All selected correlations overestimate the HTC at the top wall. The Shah correlation demonstrates the best prediction accuracy for the HTC at the bottom wall, both at near atmospheric pressure (Mean Relative Error, MRE = 21 %) and at negative pressure (MRE = 19 %).

Numerical investigation into the thermo-hydro-mechanical behavior in unsaturated soils considering hypergravity effect

Unsaturated soils are commonly found in coastal regions and marine sediments, where understanding the thermo-hydro-mechanical (THM) behavior, especially regarding phase transition, is crucial for related practical engineering applications. Centrifugal model offers an effective means to reflect the prototype with smaller scale and shorter duration under hypergravity conditions. Present studies on similarity based on governing equation analysis of the THM coupled responses are mainly focused on saturated rather than unsaturated soils, nor involved with different boundary conditions. This paper theoretically derives the similarity of THM behavior of unsaturated soils between the centrifugal model and prototype, and numerically assesses the similarity considering Dirichlet / Neumann condition based on the open-source FEM code OpenGeoSys. In addition, numerical results shows that phase transition between liquid water and water vapor will occur under temperature variation, and pore pressure difference rather than initial pore pressure causes the difference of THM coupled responses. Significant pore pressure variation will be amplified with increase of gas diffusion coefficient, and large air entry pressure corresponds to high liquid saturation and obvious phase transition.