Formation Behavior Research Articles

Sterile Alpha Motif Domain-Containing 5 Suppresses Malignant Phenotypes and Tumor Growth in Breast Cancer: Regulation of Polo-Like Kinase 1 and c-Myc Signaling in a Xenograft Model.

Background Breast cancer, particularly the triple-negative breast cancer (TNBC) subtype, remains a significant clinical challenge due to its resistance to standard chemotherapy and high recurrence rate. In this study, we explored the role of Sterile Alpha Motif Domain-Containing 5 (SAMD5) as a potential regulatory partner with the c-Myc oncogenic signaling pathway in breast cancer. Materials and methods Functional assays were conducted to investigate the effects of SAMD5 overexpression on cell viability, colony formation, and invasive behavior in TNBC cell lines. This study further assessed the expression levels of proliferation and invasion markers, including Ki67 (a marker for cell proliferation), Matrix Metalloproteinase-2 (MMP2), and Matrix Metalloproteinase-9 (MMP9). Mechanistic analyses identified a negative correlation between SAMD5 and Polo-like Kinase 1 (PLK1), a gene frequently overexpressed in breast cancer, particularly in TNBC. The effects of PLK1 knockdown on cell viability, colony formation, and invasion were observed, along with the impact of PLK1 overexpression on SAMD5's inhibitory activity. In vivo studies were performed using a xenograft tumor model in nude mice to evaluate the impact of SAMD5 overexpression on tumor weight and volume. Results SAMD5 overexpression significantly reduced cell viability, colony formation, and invasion in TNBC cells, and downregulated key proteins in the c-Myc signaling pathway, including c-Myc itself, β-catenin, Cyclin-Dependent Kinase 4 (CDK4), Cyclin-Dependent Kinase 6 (CDK6), and Cyclin D1. PLK1 overexpression was found to counteract SAMD5's inhibitory effects. In vivo experiments demonstrated that SAMD5 overexpression led to a marked reduction in tumor weight and volume, effects that were partially reversed by PLK1 overexpression. Conclusions SAMD5 acts as a tumor suppressor in breast cancer, particularly in TNBC, by inhibiting critical cellular processes and downregulating the c-Myc signaling pathway. This effect appears to be mediated, in part, through its negative association with PLK1. Targeting the SAMD5/PLK1 axis offers a promising therapeutic strategy for addressing aggressive breast cancers.

Comprehensive characterizations of core sediments recovered from Shenhu W17 well in South China sea and its impact on methane hydrate kinetics

Natural Gas Hydrates (NGH) is considered a vast unconventional energy source that holds significant promise in addressing future energy demands. In Shenhu area (located at northern slope of the South China Sea, SCS), there has been conducted a series of further studies of NGH such as exploration, drilling, and twice field production testing. The lithological characteristics of cores from marine sediments and their influence on methane hydrate (MH) formation are relatively unknown and merits further investigation. In this study, we conducted a chain of lithological characterization on the core sediments recovered from Shenhu W17 well, the coring well which located near the 1st NGH field production in SCS. The core sediments are classified as clayey-silt, its median grain size is 6.91 μm, comprising primarily clay minerals, quartz, and calcite. According to X-ray diffraction analysis, the main content of clay minerals is illite-smectite layers, illite, chlorite, and kaolinite, respectively. Porosity of the core sediments is 32.5% and the permeability is 7.8 mD based on mercury intrusion tests. Four types of primary pores are identified based on SEM and QEMSCAN analysis: intergranular pore, intercrystalline pore, intragranular pore, and pores associated with marine fossils. Moreover, the influence of the recovered core sediments (0–40 wt%) on MH formation kinetics were examined with morphology observed to elucidate the MH-core sediments interaction. The induction time was reduced significantly to ∼20 min in the presence of SCS core sediments. A two-stage MH formation behavior is observed with a maximum gas uptake of 134.1 Vg·Vw−1: (a) an initial MH formation at the gas-liquid interface with MH upward growth and fine-grain sediments migration; and (b) a second stage of significant MH growth with layered formation of MH and core sediments. The capillary channels of MH formed facilities the migration of core sediments, which in turn provides additional gas-liquid contact area for MH formation. The study provides valuable insights on the role Shenhu core sediments in MH formation, which is essential for understanding the spatial heterogeneity of NGH in reservoir and for designing suitable production strategy.

Numerical Modeling and Experimental Validation of Icing Phenomena on the External Surface of a U-Bend Tube

The regasification of liquefied natural gas (LNG) is a crucial process that involves certain challenges created by the low temperature of LNG and the risk of ice formation on the external surfaces of the tubes of heat exchangers, which can hinder heat transfer and increase flow resistance. This study presents a numerical model for ice formation on the external surface of the U-bend tube of shell-and-tube heat exchangers. The numerical model has been further enhanced by applying a custom user-defined function. The numerical results were validated using experimental data and demonstrated excellent predictive capability, particularly for the surface temperature of the tubes and the thickness of the ice layer. Hence, this model can reliably capture the overall behavior of the ice formation on the external surfaces of the tubes of shell-and-tube heat exchangers. By highlighting the importance of maintaining stable heat transfer conditions to prevent freezing, this study offers valuable insights that can guide the optimization of heat exchanger designs for LNG regasification.

Digital Device Usage and Childhood Cognitive Development: Exploring Effects on Cognitive Abilities.

The present narrative overview explored the complex relationship between digital device usage and cognitive development in childhood. We conducted a comprehensive literature search across multiple databases, including PubMed, Embase, Scopus, and Web of Science, to critically assess cognitive domains such as attention, memory, executive functions, problem-solving skills, and social cognition. Incorporating over 157 peer-reviewed studies published between 2001 and 2024, we used strict inclusion and exclusion criteria to ensure scientific rigor. The review integrated empirical findings with established theoretical frameworks, particularly from cognitive development and media psychology, to highlight both the advantages and risks of early, frequent exposure to technology. The potential for digital devices to enhance cognitive skills, such as multitasking and information processing, was weighed against risks such as cognitive overload, diminished attention spans, and impaired social skills. We also examined psychological and behavioral outcomes, including identity formation, emotional regulation, and maladaptive behaviors associated with excessive screen time. Additionally, we identified strategies to mitigate negative effects, emphasizing structured digital engagement and parental involvement to support healthy cognitive and psychological growth. Our findings provided actionable recommendations for parents, educators, and policymakers, promoting optimal digital practices that enhanced cognitive development while safeguarding against potential harms. The review offered essential insights for stakeholders in child development, education, and policy-making, highlighting the need for balanced integration of digital tools in childhood learning environments.

Carbon Dot Synthesis and Purification: Trends, Challenges and Recommendations

AbstractCarbon dots (CDs) have rapidly emerged as a new family of carbon‐based nanomaterials since their initial discovery two decades ago. Numerous appealing properties, such as precursor and synthesis process flexibility, tunable photoluminescence, and good biocompatibility, have enabled their widespread applications in sensing, catalysis, energy, and biomedical fields. As the field expands, notable efforts have recently focused on mechanistically elucidating the structural formation and optical behavior of CDs. However, the absence of “clean” CDs presents a major obstacle to achieving a solid understanding of these aspects. Often, the claimed CDs are, in fact, a mixture of small molecules, oligomers, nano‐sized aggregates, or even microparticles. Such coexistence of impurities markedly impacts the physicochemical properties of resulting CD‐based mixtures, hampering the resolution of key mechanistic questions. Here, we aim to address this fundamental shortcoming of the field, going beyond the customary focus of the existing reviews that predominantly cover synthesis, optical performance, and application prospects. We begin with an overview of CD synthesis and then thoroughly examine the purification methods, including filtration, dialysis, electrophoresis, and chromatography. The insights provided here will guide the researchers towards obtaining high‐quality CDs, employing proper combinations of available tools, and ultimately paving the way for more demanding applications.

Movement behavior and morphological change of droplets on vertically crossed fibers

Droplet capture and coalescence are critical processes for enhancing emulsion separation efficiency in oily wastewater treatment. In this paper, four kinds of motion behaviors and secondary droplet formation behaviors of oil droplets on vertically crossed fibers in a water environment were investigated using high-speed camera technology. The research shows that during the droplet capture process, droplets on large-diameter horizontal fiber exhibit greater lateral spreading, and smaller vertical elongation. Increasing the diameter of horizontal fiber significantly shortens droplet capture time. The capture time on lipophilic fiber intersection of 190–420 μm is 14 ms less than that of 190–190 μm. During the droplet coalescence process, the liquid bridge on large-diameter horizontal fiber is wider, and the droplet contraction ratio is smaller. The droplet contraction ratio on fiber intersection of 190–420 μm is 0.3 smaller than that of 190–190 μm. Increasing the diameter of horizontal fiber can promote rapid fusion between droplets, but lipophobic fibers hinder the degree of fusion and deformation. Furthermore, the diameter and wettability of horizontal fibers have significant effects on the volume of secondary droplets. The volume of secondary droplets increases with the diameter of lipophilic horizontal fiber in the capture process. The volume of secondary droplets on lipophilic horizontal fiber is approximately three times larger than that on lipophobic horizontal fiber in the coalescence process. These findings contribute to understanding the details of coalescence separation and optimizing the design of fiber fillers.

Designing Robust Single Atom Catalysts by Three-in-One Strategy: Sub-1-nm Space Confining, Bimetallic Bonding and Reaction-Induced Forming Active Sites.

It is imperative to design robust single atom catalysts (SACs) that maintain the stability of the active component under diverse reaction conditions and prevent aggregation or deactivation. Confining the single atom active site within sub-nanometer (sub-1-nm) spaces has proven effective in enhancing the stability and activity of the catalyst, owing to the strong constraints and regulations imposed on atomic behavior at this scale. Bimetallic bond atomic sites, comprising two distinct metal compositions, often exhibit unique electronic structures and catalytic properties. Designing SACs under reaction-induced conditions, such as varying temperatures, pressures, and atmospheres, can facilitate a deeper understanding of the formation and migration behavior of active sites in real reactions, as well as the optimization mechanisms for performance enhancement. The objective of this review is to promote a robust SAC design strategy that encapsulates bimetallic bonding active sites within sub-1-nm spaces and investigates catalyst preparation and performance under reaction-induced conditions. This design strategy is anticipated to bolster the catalytic activity and stability of the catalyst while also offering fresh perspectives and optimization avenues for the catalytic processes involved in practical chemical reactions.

Influence of Al2O3 Nanoparticles on the Morphology and Growth Kinetics of Cu-Sn Intermetallic Compounds in Sn-Ag-Zn/Cu Solder Joints

Intermetallic compounds (IMCs) growth can simultaneously bring about low-resistance electrical pathways and drastically reduce joint lifetime. Recently, incorporated trace nanoparticles into the free-Pb solder were found to promote the performance of the solder joints. Sn3Ag0.9Zn (SAZ) nano-composite solders were developed by doping 0.5 wt.% Al2O3 nanoparticles into the SAZ solder. The IMCs formation and growth behavior at the interfacial reactions between the SAZ-0.5Al2O3 nano-composite solder and the Cu substrate during soldering at temperatures ranging from 250 to 325 °C for 30 min were investigated. The results showed that after the addition of Al2O3 nanoparticles into the SAZ solder, the elongated-type IMCs layer changed into a prism-type IMCs layer, and Ag3Sn nanoparticles were absorbed on the grain surface of the interfacial Cu6Sn5 phase, effectively suppressing the growth of the IMCs layers. The activation energies (Q) for the IMCs layers (Cu6Sn5 + Cu3Sn) were determined to be 36.4 and 39.1 kJ/mol for the SAZ/Cu and SAZ-Al2O3/Cu solders, respectively.

Identifying bound compounds in non-extractable residues of pesticides in soil by 4-pool kinetic analysis

This study explores the feasibility of identifying bound compounds in non-extractable residues (NERs) of pesticides in soil by 4-pool kinetic analysis. The 4-pools refer to parent compound, metabolites, NERs, and CO2 in 14C-labeled pesticide soil degradation studies. We discovered the following two characteristic 4-pool kinetic behaviors of formation of NERs: (1) if parent compound is bound as NERs, the metabolites (m(t) in % applied radioactivity (AR)) kinetically drive the evolution of CO2 only; and (2) if a metabolite (x) in a sequential degradation pathway is bound as NERs, m(t) is split into m1(t) and m2(t) at the metabolite (x) that is bound as NERs, which kinetically drive the formation of NERs and evolution of CO2 respectively. We developed two (i.e., Parent➔NER and metabolite➔NER) 4-pool models to capture the kinetic behaviors respectively. By fitting the models to a set of 4-pool data, we not only determine whether NERs form from parent compound or metabolites but also identify the bound metabolite (x) by resolving the metabolites into M1(t) and M2(t) (i.e., the variables used to simulate m1(t) and m2(t)) and then matching m1(t) (i.e., the sum of the bound metabolite (x) and its metabolite precursors) with M1(t). By applying the models to 14C-labeled parent compound-dosed studies and then sequentially to metabolite-dosed studies for 7 pesticides with ≥70 % AR NERs, we identified the bound compounds, which have the moieties known to be responsible for NERs, are bound as NERs instantaneously when dosed into soil, and account for pH dependency of NER formation.

Investigation of bubble formation in high-temperature water and silicone oil under submerged orifice gas injection conditions

In diverse disciplines such as chemical engineering, metallurgy, and environmental engineering, the formation of bubbles through submerged orifice gas injection bears significant implications. However, the disparate characteristics of liquid mediums, notably between volatile and non-volatile liquids, often pose challenges to the universal application of bubble dynamics research findings. To bridge this gap, physical experiments utilizes both volatile (water) and non-volatile (silicone oil) liquids, aiming to elucidate the behavior of bubble formation under high-temperature liquid conditions. Experimental outcomes revealed an inverse relationship between liquid temperature and bubble detachment diameter: in water, the diameter increased, whereas in silicone oil, it decreased. Detailed analysis showed a 4.4 % increase in water bubble diameter within a 20–50 °C range and a 33.3 % increase within a 20–90 °C range. Conversely, in silicone oil, the diameter decreased by approximately 12.5 % within the 20–90 °C range. Mechanistic insights, derived from numerical simulations and ideal gas theory, revealed that a 50 °C temperature change led to a 27.7 % increase in bubble detachment diameter due to water evaporation, a 5.4 % increase due to gas thermal expansion, and a 2.1 % decrease due to alterations in surface tension coefficient and viscosity. To further investigate the formation and temperature rise of bubbles under thermal coupling, numerical simulations were conducted to obtain the variations in relevant characteristic parameters. The study reveals a two-stage temperature increase within the bubble, providing theoretical insights for the investigation of bubble dynamics under multiple physical fields coupling conditions.

Flocculation of fiber suspensions studied by Rheo-OCT

When dealing with papermaking fiber suspensions, particle flocculation takes place even before the paper web is formed. The particle flocculation depends on several aspects, including particle mass concentration (consistency), particle collisions, electrochemical interactions promoted by chemical additives, etc. Due to its impor-tance, fiber suspension flocculation has been studied for a long time in papermaking, and several methods have been developed for this purpose. The traditional techniques include, for example, focused beam reflectance micros-copy (FBRM) and high-speed video imaging (HSVI). Recently, a new optical method, optical coherence tomography (OCT), has emerged for flocculation analysis. The advantages of OCT are the possibility to study opaque suspensions, its micron-level resolution, and its high data acquisition speed. The OCT measurements can be combined with rheological (Rheo) measurements, allowing simul-taneous measurement of both the time evolution of the floc size and the suspension viscosity. In this work, we used this approach, Rheo-OCT, to study the flocculation of suspensions of various papermaking furnishes. We analyzed the time evolution of the floc size and the fiber suspension viscosity when the studied paper-making suspensions were treated with highly refined furnish (HRF) — a furnish that contained a significant amount of micofibrillated cellulose (MFC)-type fibrils — and/or chemical additives. Such studies can lead to a better under-standing of the impact of flocculation on the produced paper web in terms of qualities like formation, drainage potential, and strength behavior.

Negative Effect of the Calendering Process on the Interphase Formation and Electrochemical Behavior of Reduced Graphene Oxide Electrodes.

Many studies on electrode material development for rechargeable batteries have focused on improving the intrinsic physicochemical and electrochemical properties of active materials, but the electrochemical performances of batteries are exhibited by the overall electrode unit consisting of active materials, conductive additives, and a binder. Additionally, the electrodes have undergone an essential calendering process to enhance the physical contact between those components. Therefore, the electrochemical behavior and performance of a cell should be analyzed at the electrode level, as the inherent properties of active materials might be changed in electrode preparation, including the calendaring process and real-operating environments. In this study, we aimed to understand the electrochemical properties of the reduced graphene oxide (RGO)-containing electrodes rather than the RGO-active materials by studying the changes in the RGO electrode before and after the calendering process. Specifically, the study investigates the effect of the calendering process on the electrochemically active interphase formation and electrochemical properties of the RGO electrode. We found that the calendering process deteriorates the electrochemical properties of RGO electrodes by impeding enough electrolyte wetting, limiting the formation of thin and stable solid-electrolyte interphase, and leaving unreacted RGO sheets. Additional experiments with carbon-coated silicon/RGO composite electrodes demonstrate that after the calendering process, the sequential participation of Si/C particles in the electrochemical reaction resulted in much more severe capacity degradation over repeated cycling processes. The studies suggest that fine-controlling the number of RGO sheets and maintaining enough distance between those sheets even after the calendering process are required for the utilization of RGO in rechargeable batteries.

Immiscible non-Newtonian displacement flows in stationary and axially rotating pipes

We examine immiscible displacement flows in stationary and rotating pipes, at a fixed inclination angle in a density-unstable configuration, using a viscoplastic fluid to displace a less viscous Newtonian fluid. We employ non-intrusive experimental methods, such as camera imaging, planar laser-induced fluorescence (PLIF), and ultrasound Doppler velocimetry (UDV). We analyze the impact of key dimensionless numbers, including the imposed Reynolds numbers (Re, Re*), rotational Reynolds number (Rer), capillary number (Ca), and viscosity ratio (M), on flow patterns, regime classifications, regime transition boundaries, interfacial instabilities, and displacement efficiency. Our experiments demonstrate distinct immiscible displacement flow patterns in stationary and rotating pipes. In stationary pipes, heavier fluids slump underneath lighter ones, resulting in lift-head and wavy interface stratified flows, driven by gravity. Decreasing M slows the interface evolution and reduces its front velocity, while increasing Re* shortens the thin layer of the interface tail. In rotating pipes, the interplay between viscous, rotational, and capillary forces generates swirling slug flows with stable, elongated, and chaotic sub-regimes. Progressively, decreasing M leads to swirling dispersed droplet flow, swirling fragmented flow, and, eventually, swirling bulk flow. The interface dynamics, such as wave formations and velocity profiles, is influenced by rotational forces and inertial effects, with Fourier analysis showing the dependence of the interfacial front velocity's dominant frequency on Re and Rer. Finally, UDV measurements reveal the existence/absence of countercurrent flows in stationary/rotating pipes, while PLIF results provide further insight into droplet formation and concentration field behavior at the pipe center plane.

Evolution of Power‐Law Particle‐Size Distributions in Dense Grain‐Flow Experiments

AbstractUnderstanding particle fragmentation and its resulting particle‐size distribution is essential for comprehending shear zone formation, structure, and frictional behavior in faults and landslides, particularly at high normal stresses. 3‐D fractal dimension (D3) is used as a measure of particle‐size distribution, and for the potential self‐similarity physics. Previous research suggests D3 – 2.58 based on the “constrained comminution” model, or D3 = 3.00 considering large shear displacement. However, field data from rock avalanches reveal scattered D3 that deviate from these predictions, possibly due to the neglection of the underlying fragmented physics, such as the particle‐size‐dependent fragmentation probability. Herein, we conducted rotary shear experiments to investigate the evolution of D3 under varying normal stresses, velocities, and mineral compositions. Experimental results demonstrate that D3 monotonically increases with shear displacement and converges to an ultimate value, significantly influenced by mineral composition but less affected by shear velocity and confining stress within the experimental conditions. A modified large‐strain model that considered size‐dependent grain‐breakage probability was proposed, which may explain the observed divergence of D3 from previous predictions. This model highlights the complex mechanisms involved in particle breakage within dense grain‐flows, resulting in the high but scattered D3 observed in natural shear zones. Furthermore, we recognize that additional mechanisms, such as abrasion and grinding, can contribute to the particle size reduction and influence the ultimate fractal dimension. This study provides valuable insights into the dynamics of particle fragmentation in shear zones and has implications for understanding various geological processes.

Comparison of microstructural evolution and high temperature oxidation behavior of AlCoCrFeNiTi and AlCoCrFeNiZr high-entropy alloy coatings

In this study, the isothermal oxidation behaviors of HEA coating systems with AlCoCrFeNiTi and AlCoCrFeNiZr contents were evaluated by comparing microstructurally and investigated in terms of potential applications of thermal barrier coatings (TBCs). For this reason, their oxidation resistance under isothermal conditions, as well as diffusion phenomena occurring at the bond and top coating interface, were investigated. CoNiCrAlY bond coating was applied to the surface of a Nickel-based superalloy substrate by high velocity oxygen-fuel (HVOF) spraying. HEA coating materials were produced by using the mechanical alloying (MA) process. The mechanical activated synthesized HEAs were sprayed on a CoNiCrAlY bond coating by Atmospheric Plasma Spraying (APS). The microstructural changes at the coating interface of CoNiCrAlY, AlCoCrFeNiTi and AlCoCrFeNiZr (HEAs) coatings resulting from oxidation processes at 1200 °C for 5, 25, 50 and 100 h, and the formation and growth behaviors of the thermally grown oxide (TGO) layer were investigated. The present results demonstrate a potential of HEAs in TBC applications. After oxidation tests, crystal lattice transformations took place in both coating systems. In the AlCoCrFeNiZr-HEA TBC system, an increase in diffusion rate, oxygen permeability, and consequently TGO layer thickness was observed by the transformation from the cubic lattice structure to a monoclinic lattice structure with a larger volume. In the AlCoCrFeNiTi-HEA TBC system, the transformation of a narrow rhombohedral lattice with tight planes was maintained. Therefore, the TBC system with AlCoCrFeNiTi-HEA has a lower TGO layer thickness compared to the TBC system with AlCoCrFeNiZr-HEA and has a longer service life against oxidation failure at high operating temperatures. As a result of the production, experimental studies and high temperature oxidation test studies under service conditions, it was seen that AlCoCrFeNiTi and AlCoCrFeNiZr-HEA coatings can be used in the structure of TBC systems.

Prediction of Hydrate Formation in Supercritical CO2 Containing Impurities Long-Distance Transportation Pipelines with a Capacity of 0.36 Million t/a

Abstract Long-distance pipeline transportation is the most economical and feasible way to transport CO2. Hydrates can easily form during the transportation of supercritical CO2 containing impurities, leading to pipeline blockage. Therefore, accurate prediction of the deposition location and amount of hydrates in pipelines is crucial. This paper established a prediction model for hydrate growth in the long-distance CO2 transportation pipeline containing impurities. The phase equilibrium diagram and kinetic growth model were combined to simulate the formation behaviour of CO2 hydrate. The long-distance CO2 transportation pipeline of 0.36 million t/a in Yunlin was taken as an example. The results show that the volume of CO2 hydrate increased whereas the growth rate of CO2 hydrate gradually decreased with time. Hydrates begin to form in pipeline L11 at a distance of 35-44.3 km away from the inlet, whereas at a distance of 8.1 km away from the inlet for pipeline L12. The places with the highest amount of hydrate formation in both of the pipelines were at the end of pipelines. The area for hydrates formation in pipeline L12 was much longer than that in pipeline L11 due to the lower temperature. The cleaning cycle for pipeline L12 should be much shorter than that of pipeline L11. This paper will provide guidance for the operation of CO2 long distance pipelines.

Production characteristics in initial pyrolysis of lignin based on reactive molecular dynamics simulations

Abstract Carbonization, direct liquefaction, and gasification, which are based on pyrolysis reactions, have been proposed as efficient technologies for energy recovery from biomass resources. However, modeling pyrolysis reactions of biomass with complex molecular structures is challenging, and numerical analysis methods that consider product compositions have not yet been established. In this study, molecular dynamics simulations were performed using LAMMPS, with the force field parameterized using ReaxFF. A molecular model based on Adler softwood lignin was created. The atomic trajectories were analyzed to identify the products of the pyrolysis process, and changes over time in inorganic gas, organic gas (C1-C4), light tar (C5-C14), heavy tar (C15-C39), and char (C40+) during the initial pyrolysis of lignin were investigated. The distribution of compositions formed and the formation behavior of typical low-molecular-weight components (such as formaldehyde and methanol) and inorganic gases from lignin were evaluated. The characteristics of the products in the initial pyrolysis of lignin, as analyzed from the molecular dynamics simulations, were based on the functional groups in the molecular model of lignin. Furthermore, similarities with the product compositions identified in experiments were also confirmed.

Kinetics of methane hydrate formation in a 1200 ml unstirred reactor for natural gas storage

Solidified natural gas (SNG) technology via clathrate hydrates, enhanced by promoters such as tetrahydrofuran (THF), promises large-scale natural gas storage due to its high volumetric capacity and mild storage conditions. Despite its potential for industrial scale-up, limited research exists on methane hydrate formation behaviors in large reactors (>1000 cm3), which is crucial for evaluating practical storage performance. In this study, methane hydrate formation kinetics were investigated in a scaled-up unstirred reactor (1200 cm3) at 288.15 K and 283.15 K, and 5.0 MPa. Methane uptake, system pressure, gas and liquid phase temperatures, and hydrate morphologies were analyzed to describe the dynamic hydrate formation process. Results reveal three effects of increased reactor size in contrast to smaller reactors: (i) heterogeneous distribution of THF-rich and methane-rich hydrates; (ii) hydrate bulk show a hollow inner structure with a cavity due to the wall-climbing behavior of hydrate growth; (iii) optimal THF concentration no longer always agrees with stoichiometric 5.56 mol%, which is case-dependent. These effects are attributed to higher diffusion resistances for methane molecules and more intensive heat accumulation. These findings provide some insight into the kinetics of methane hydrate formation in industrial reactors, which is critical for the commercialization of SNG technology.

Pressure-dependent optoelectronic properties of TlInS2 crystals (II): Insights from DFT simulations

This study investigates the structural and optical properties of TlInS2 crystals under elevated pressures using density functional theory (DFT). The dielectric function shows significant shifts under pressure, indicating changes in electronic transitions and band structures. Analysis of the refractive index reveals pressure-induced spectral peaks and a semiconductor-to-metal transition at 6.25 GPa. Reflectivity measurements show an increase with pressure, reaching 0.504 at 10 GPa, suggesting enhanced optical properties. Optical conductivity analysis shows increased total conductivity with pressure due to reduced band gap energy, stimulating exciton formation and metallic behavior beyond 6.25 GPa. These comprehensive insights into the pressure-dependent behaviors of TlInS2 are essential for potential applications in electronic and optoelectronic devices.

Internal oxidation behavior and its effect on the surface crack formation in a Fe-Mn-Al-C high Mn steel

The correlation between internal oxidation and surface crack was investigated in high Mn steel. Time- and temperature-dependent internal oxidation behaviors are examined in the temperature ranges of 1000– 1250 °C, revealing faster and deeper oxidation along grain boundaries than in grain. Oxides at the internal oxidation layer are confirmed to be MnO and MnAl2O4. The grain boundary penetration depths of the internal oxide increase from 13 to 34 μm as the temperature increases. The tensile crack on the surface of the specimen was evaluated after 5 % straining with 10−3/s strain. Temperature-dependent crack formation probability (LAC/LT) increases also from 0.4 to 1.6 % as the temperature increases. The evolution of the internal oxidation layer during the hot compression test was investigated to clarify its role in surface crack formation. The transition of the internal oxide layer to the external oxide layer was observed. Exfoliation of the external oxidation layer was also confirmed by further compression. Driving force calculation on the internal and external oxides reveals that the abundant oxygen supply originating from the cracking of oxide and thickness reduction of the internal oxide layer transforms the internal oxide layer to scale during the compression. High-resolution analysis of the grain boundary crack reveals the cracking of grain boundary MnAl2O4. The comparison between the grain boundary oxides’ penetration depth and the crack formation behavior clarifies the grain boundary internal oxide’s crucial role in the surface crack formation in a high Mn steel. This study provides vital insights into the surface crack formation mechanism in a Fe-Mn-Al-C-based high Mn steel during hot-rolling processes, highlighting the significance of grain boundary internal oxidation in production.