Transition Behavior Research Articles

Exploring diabetic patients’ intention to switch POCT self-monitoring glucose devices: investigating influence of perceived usefulness and perceived ease of use

Purpose The study aims to examine diabetic patients’ switching intentions toward self-monitoring blood glucose devices, incorporating perceived usefulness and perceived ease of use, with switching cost as a moderator. Design/methodology/approach A self-administered questionnaire was developed using established measuring scales. Data from 321 respondents was collected and analyzed using the partial least squares structural equation modeling approach. Findings Results indicate that perceived usefulness and perceived ease of use influence switching intention. Switching cost does not moderate the perceived usefulness, perceived ease of use and switching intention. This study reveals important information for healthcare practitioners and device manufacturers. Originality/value The significance and originality of this study stem from its pioneering investigation into the switching intentions of diabetic patients regarding self-monitoring glucose devices through the application of the technology acceptance model, thereby addressing a notable gap in the existing literature on diabetes management and technology adoption, which has lacked comprehensive examination of patients’ transition behaviors in this specific context.

A closed-form solution for thermally induced affine deformation in unbounded domains with a temporally accelerated anomalous thermal conductivity

Abstract One of the successful mathematical tools in the 21st century is the distributed-order fractional derivative, particularly, the bi-fractional diffusion equation of natural form (Chechkin, Gorenflo, and Sokolov, Phys. Rev. E 2002) and the bi-fractional diffusion equation of the modified form (Sokolov, Chechkin, and Klafter, Acta Phys. Pol. B 2004). The present study adopts the bi-fractional diffusion heat equation of the modified form that uses two Riemann-Liouville time-fractional derivatives with different fractional orders and the Riesz space-fractional derivative, and bears the property of variable thermal conductivity with temporal acceleration; i.e., the material thermal conduction transits from a low value at the small values of time ($t\to 0$) to a larger value at the long-time domain ($t\to \infty$). The corresponding fractional thermoelasticity theory, that uses the bi-fractional diffusion heat equation of the modified form, is exclusively considered in this work. For a quasi-static unbounded Hookean domain, exact solutions for the temperature, hydrostatic stress, and the displacement fields are derived in both short-time and long-time domains, in terms of the Fox \textit{H}-function. The exact solutions for the linearized problem are derived using the inversion of problem variables from the Laplace-Fourier space. Adding a zero initial condition on the normal stress of the unbounded space transforms the conventional Cauchy problem to a mixed initial-boundary value problem in order to derive a generalized form of the displacement. Additionally, thermal energy is not conserved in the presence of space fractality. The effect of such an accelerating transition in the thermal conduction on the displacement component is focused on, and it is found that the displacement inherits a similar transition behavior.

Kibble-Zurek behavior in a topological phase transition with a quadratic band crossing

Kibble-Zurek behavior in a topological phase transition with a quadratic band crossing

Microstructural and Performance Analysis of (TiAl)95−xCu5Nix Coatings Prepared via Laser Surface Cladding on Ti–6Al–4V Substrates

In this study, the surface of (Ti-6Al-4V)TC4 alloy was modified via laser cladding. The elemental composition of the coating was (TiAl)95−xCu5Nix, with Ni as the variable (where x = 0, 3, 6, and 9 at.%). Multi-principal alloy coatings were successfully prepared, and their constituent phases, microstructures, and chemical compositions were thoroughly investigated. The hardness and wear resistance of the coatings were analyzed, and the compositions and interfacial characteristics of the different phases were examined via transmission electron microscopy. The analysis revealed that Ni formed a solid solution and a eutectic structure in the Ti(Al, Cu)2 phase. These findings provide valuable insights into the coating properties. Moreover, reciprocal dry sliding friction experiments were conducted to investigate the wear mechanism. The results revealed a significant increase in wear resistance owing to the formation of a Ni solid solution and changes in the coating structure. Additionally, tensile tests demonstrated that the tensile strength of the coatings initially increased and then decreased with varying Ni content. By combining these results with various analyses, we determined that the coating exhibited optimal properties at a Ni content of 6 at.%. Overall, this study comprehensively investigated the microstructure and phase transition behavior of these coatings through various analytical techniques. These findings provide valuable guidance for further optimizing both the preparation process and the performance of the coatings. The coatings exhibit excellent wear resistance and could inspire the design of more advanced protective surfaces.

Macroscopic perspective on phase transition behavior of natural single-crystal graphite under different pressure environments

Comprehensive understanding of the direct transformation pathway from graphite to diamond under high temperature and high pressure has long been one of the fundamental goals in materials science. Despite considerable experimental and theoretical progress, current experimental studies have mainly focused on the local microstructural characterizations of recovered samples, which has certain limitations for high-temperature and high-pressure products, which often exhibit diversity. Here, we report on the pressure-induced phase transition behavior of natural single-crystal graphite under three distinct pressure-transmitting media from a macroscopic perspective using in situ two-dimensional Raman spectroscopy, scanning electron microscopy, and atomic force microscopy. The surface evolution process of graphite before and after the phase transition is captured, revealing that pressure-induced surface textures can impede the continuity of the phase transition process across the entire single crystal. Our results provide a fresh perspective for studying the phase transition behavior of graphite and greatly deepen our understanding of this behavior, which will be helpful in guiding further high-temperature and high-pressure syntheses of carbon allotropes.

Veteran suicide thoughts and attempts during the transition from military service to civilian life: Qualitative insights

A rapidly growing literature highlights a critical need for targeted suicide prevention and risk mitigation strategies for veterans navigating the military-to-civilian transition. Although various risk correlates of suicidal thoughts and behavior among transitioning veterans have been identified, how and why these correlates occur and interact to affect suicidality remains unclear. Guided by the 3 Step Theory of Suicide, 10 recently discharged United States military veterans with a history of post-discharge suicide thoughts, urges, or behaviors completed interviews on the military-to-civilian transition and suicidal thoughts and behaviors occurring during this time. Thematic analysis highlighted an overarching theme of transition whiplash comprising four subthemes: unpreparedness, economic vulnerability, identity disruption, and social alienation. Veterans’ recommendations for improving suicide-prevention efforts included providing a primary contact to provide personalized support and guidance throughout transition and increasing accessibility of peer support. Results provide nuanced insight into experiences that may underlie suicide risk during the military-to-civilian transition.

Phase transition behaviors of Sr0.72Ca0.28Fe1-xNixO3-δ perovskite oxygen sorbents in a fixed bed reactor

Perovskite oxides have emerged as promising materials for oxygen storage applications, with their phase transitions being a key area of research. This study reports on the unique oxygen absorption and desorption breakthrough curves observed in the Sr0.72Ca0.28Fe1-xNixO3-δ series (x = 0.05) during fixed-bed experiments, featuring a distinct plateau. Through in situ X-ray diffraction (XRD) analysis, we demonstrated the reversible phase transition between the perovskite and brownmillerite (BM) structures. High Resolution Transmission electron microscopy (HR-TEM) further revealed the coexistence of these two phases within a granule. Focusing on the Sr0.72Ca0.28Fe0.95Ni0.05O3-δ sample at 550 °C, we conducted a detailed analysis of the oxygen absorption curve. Our findings indicate that the plateau arises from the oxygen-deficient BM phase absorbs oxygen to form the oxygen-saturated BM phase, followed by further oxygen absorption, leading to the formation of the perovskite phase. The inflection point in the oxygen absorption curve marks a critical oxygen concentration, signifying the threshold for effective oxygen absorption. This critical concentration is influenced by both material composition and operation temperature. Based on our observations, a phase diagram for x = 0.05 was drawn, encompassing both oxygen concentration and temperature. This diagram allows for the rational selection of operation temperatures and oxygen concentration swing ranges to enhance the performance of the oxygen sorbent. Our study highlights the crucial role of phase transition in oxygen storage, offering insights into the design and development of high-performance perovskite-based materials for various applications.

Stable and unstable fall motions of plate-like ice crystal analogues

Abstract. The orientation of ice crystals affects their microphysical behaviour, growth, and precipitation. Orientation also affects interaction with electromagnetic radiation, and through this it influences remote sensing signals, in situ observations, and optical effects. Fall behaviours of a variety of 3D-printed plate-like ice crystal analogues in a tank of water–glycerine mixture are observed with multi-view cameras and digitally reconstructed to simulate the falling of ice crystals in the atmosphere. Four main falling regimes were observed: stable, zigzag, transitional, and spiralling. Stable motion is characterised by no resolvable fluctuations in velocity or orientation, with the maximum dimension oriented horizontally. The zigzagging regime is characterised by a back-and-forth swing in a constant vertical plane, corresponding to a time series of inclination angle approximated by a rectified sine wave. In the spiralling regime, analogues consistently incline at an angle between 7 and 28°, depending on particle shape. Transitional behaviour exhibits motion in between spiral and zigzag, similar to that of a falling spherical pendulum. The inclination angles that unstable planar ice crystals make with the horizontal plane are found to have a non-zero mode. This observed behaviour does not fit the commonly used Gaussian model of inclination angle. The typical Reynolds number when oscillations start is strongly dependent on shape: solid hexagonal plates begin to oscillate at Re =237, whereas several dendritic shapes remain stable throughout all experiments, even at Re > 1000. These results should be considered within remote sensing applications wherein the orientation characteristics of ice crystals are used to retrieve their properties.

Career transition and mentorship nexus: unmasking the mediating role of career adaptability

PurposeTo avoid indecisiveness and a lack of direction in making a successful career transition, it may be necessary to modify the career transition process through career mentorship (CM). The study aims to investigate career adaptability as pathways through which CM is related to trainees’ career transition.Design/methodology/approachA three times cross-sectional data were collected from 480 national industrial skills development program (NISDP) trainees among five industrial training fund (ITF) trainees in Southeastern Nigeria.FindingsThe analysis revealed that CM positively associated with the trainees’ career transition behaviors. CM is also positively associated with the trainees’ career adaptability. Also, career adaptability is positively associated with trainees’ career transition behaviors. Likewise, career adaptability mediated the link between CM and career transition behaviors.Originality/valueConducting the study in a previously neglected context extended our understanding of the indirect relationship between CM and trainees’ career transition behavior.

An Amorphous-to-Anatase Phase Transition Study of TiO2 Nanotubes by Temperature-Dependent Synchrotron-Based In Situ X-ray Diffraction.

TiO2 nanotubes (NTs) with amorphous and crystalline structures have attracted interest due to their wide range of applications, particularly black TiO2, which addresses the limitations of conventional TiO2 (a wide band gap of 3.0-3.2 eV). Understanding the amorphous-to-anatase phase transition is crucial for phase control of crystalline TiO2. This study investigates the size-dependent phase transition behavior of TiO2 and black TiO2 NTs using temperature-dependent synchrotron-based X-ray diffraction. Thermal treatments reveal that phase transitions occur in the ranges of 210-240 °C for normal NTs and 270-300 °C for black NTs. The onset temperature and crystallization growth are dependent on size, especially NT length, at least in the system under investigation. We observe anisotropic crystallization in quantum confinement, with the unit cell undergoing compression in the a-axis and expansion in the c-axis during crystallization. The longest black NTs (BV50T4) show a significant difference in the c/a ratio. Defects, such as oxygen vacancies, localize on specific NT planes.

7615 Genomic Consequences of GRHL2 Overexpression in ER+ Breast Cancer Cells

Abstract Disclosure: K.O. Allen: None. C. Zheng: None. N. Solodin: None. M.S. Ozers: Owner/Co-Owner; Self; Proteovista, LLC. C.L. Warren: None. P.E. Messa: None. D.T. Vogt: None. E.T. Alarid: None. Breast cancer progression is characterized by the presence and prevalence of metastatic disease. At a genomic level, metastasis can be facilitated via rearrangement of the chromatin landscape to expose oncogenic genes for transcription. Grainyhead like protein 2 (GRHL2) is a nuclear transcription factor implicated in epithelial cell differentiation. The GRHL2 motif has been found near activated estrogen receptor (ER) binding sites, and elevated levels of GRHL2 have been linked to worse prognosis in hormone receptor positive breast cancer patients. In its capacity to contribute to a more severe disease state when overexpressed, GRHL2 may function as either a transcription or pioneer factor to aid in the expression of metastasis-associated genes. Our lab previously showed that GRHL2 genomic binding precedes ER binding at co-regulated binding sites. Also, overexpression of GRHL2 in MCF7 cells for 24 hours did not appreciably alter gene expression by RNA-Seq. These data taken together indicate that GRHL2 may be exhibiting pioneer factor activity. However, the specific role of GRHL2 overexpression in hormone positive breast cancer progression remains unknown. In order to examine the mechanism of GRHL2 action, GRHL2 genomic binding was investigated using a tetracycline-inducible MCF7 model that allows controlled overexpression of GRHL2. ChIP studies were performed to determine GRHL2 binding intensity at specific and genome wide GRHL2 binding sites. Specific focus was given to established GRHL2 binding sites near oncogenic genes responsible for epithelial to mesenchymal transition (EMT), dormancy, and proto-oncogenic behavior. A similar analysis examined H3K27 acetylation to validate active gene transcription. An orthogonal technology, Specificity and Affinity for Protein (SNAP) microarrays, which characterizes direct GRHL2 binding to tiled genomic regions identified in ChIP-Seq analyses from multiple labs, was utilized to discriminate direct and indirect GRHL2 binding sites. The requirement for GRHL2 transactivation function in regulation of EMT related genes was further interrogated using transactivation GRHL2 dominant negative mutants. This work aims to distinguish the transcriptional and non-transcriptional activities of GRHL2 in breast cancer cells on a genome wide level and thereby, provide a deeper understanding of how overexpressed GRHL2 contributes to hormone positive breast cancer. Presentation: 6/3/2024

Molecular Insights into the Topological Transition, Fracture, and Self-Healing Behavior of Vitrimer Composites with Exchangeable Interfaces

Molecular Insights into the Topological Transition, Fracture, and Self-Healing Behavior of Vitrimer Composites with Exchangeable Interfaces

A molecular dynamics study on the supercritical evaporation of liquid ammonia under forced convection conditions

Although the behavior of the supercritical transition during the evaporation of liquid fuels in engine combustion chambers has been studied by many researchers, the effects of convection on the phase transition of liquid fuel in supercritical environments have been little studied. Previous studies mainly focused on hydrocarbon fuels for supercritical evaporation, with fewer on the zero-carbon liquid ammonia fuel. Aiming at the above deficiencies, this study used molecular dynamics simulations (MD) to explore the phase transition of liquid ammonia in a nitrogen supercritical environment under forced convection conditions. The Peng-Robinson equation of state (PR-EoS) was used to calculate the vapor–liquid equilibrium of the ammonia–nitrogen system to determine the supercritical transition time of liquid ammonia under forced convection conditions. The effects of forced convection on the heat and mass transfer process and the evolution of the liquid-phase region and the vapor–liquid interface region were analyzed. It was found that forced convection can promote the mass and heat transfer process and accelerate the phase transition of liquid ammonia to some extent. Forced convection may have a greater effect on the single-phase diffusive mixing process compared to the two-phase evaporation process. The increase in the interfacial thickness under forced convection conditions is mainly attributed to the temperature increase promoted by convection. The interfacial temperature dominates the development of its thickness and the thickness is approximately linear with temperature during the diffusive mixing stage. The shear effect induced by convection has an inhibitory effect on the diffusion of ammonia molecules within the interface region along the vertical convection direction. The cases in this study indicate that forced convection may promote the supercritical transition of liquid ammonia. In addition, a dimensionless number κ was proposed to explore the possibility of scaling up the MD results to the engineering scale.

Phase transition behavior of (MoTe2)xSb1-x thin films based on flexible PEEK substrates

Flexible information memory played a key role in flexible electronic devices and smart wearables. This paper was focused on the effect of flexible deformation on the properties of (MoTe2)xSb1-x nano-phase-change films based on PEEK substrates. By placing the films at the finger, wrist, back of the hand and elbow and bending them, the resistance values showed periodic fluctuations with bending but the changes were not significant. After 100,000 bending cycles and 4,000 s of vibration, the films successfully achieved the transformation from a shapeless to a structured state. The stress caused by bending and vibration affects the surface roughness of the flexible film and weakens the adhesion between the film and the substrate. Flexible (MoTe2)0.07Sb0.93 film electronics were prepared, and the phase change memory devices could realize reversible transitions between SET and RESET states with 100 ns pulse widths in the flat state, after 100,000 bending cycles, and after 4,000 s of vibration. These findings indicated that (MoTe2)0.07Sb0.93 films based on flexible PEEK substrates had promising applications in the field of flexible phase change memory.

Periodic information enhancing and controlling stability of complex corporate financial systems

We explore the mechanism and control behavior of how periodic information affects the stability of complex corporate financial systems from two viewpoints: the corporate life cycle and the stability of financial leverage risk. A complex corporate financial system model with correlated noise and periodic driving is proposed. Furthermore, two stability indicators are proposed to measure the stability of the corporate life cycle and the risk of corporate financial leverage. Stochastic simulation results show that enhancing the intensity and frequency of controllable periodic information can improve system stability. The stability of complex corporate life cycles and financial leverage risks exhibits opposite behaviors in terms of noise correlation. In addition, it is observed that there are specific threshold values of system parameters, and the relationship with the intensity of periodic information shows non-monotonic characteristics, manifesting peculiar phenomena and transition behaviors. Finally, by comparing with actual financial data, the proposed model is verified to be superior to the benchmark model.

Phase-space path integral approach to the kinetics of black hole phase transition in massive gravity

The dynamics of the state-switching process of black holes in dRGT massive gravity theory is presented using free energy landscape and stochastic Langevin equations. The free energy landscape is constructed using the Gibbons-Hawking path integral method. The black hole phases are characterized by taking its horizon radius as the order parameter. The free energy landscape provides three black hole phases: small, intermediate, and large. The small and large black holes are thermodynamically stable whereas the intermediate one is unstable. The Martin–Siggia–Rose–Janssen–de Dominicis (MSRJD) functional describes the stochastic dynamics of black hole phase transition. The Hamiltonian flow lines are obtained from the MSRJD functional and are used to analyze the stability and the phase transition properties. The dominant kinetic path between different phases is discussed for various configurations of the free energy landscape. We discuss the effect of black hole charge and the graviton mass on the critical behavior of black hole phase transition.

Effect of Hydrate Saturation on Triaxial Shear Mechanical Properties of Methane Hydrate-Bearing Sediment

Abstract As a clean energy source, natural gas hydrate resources are essential to the development of energy in the twenty-first century. However, the degree of consolidation of the hydrate reservoir is low, and complex accidents such as wellbore instability, reservoir collapse, and gas production leakage will be caused if improperly exploited. The laboratory employs a self-developed triaxial shear test equipment that operates under high pressure and low temperature conditions. This equipment is specifically designed to determine the mechanical parameters and strength characteristics of methane hydrate bearing sediment (MHBS) samples. It is used to create water-saturated hydrate deposits with varying levels of saturation. The synthesis of MHBS samples with varying saturations is achieved by precisely regulating the amount of water. The saturation of MHBS is then determined and confirmed by the utilization of the “water content method” and the “gas collection method.” Triaxial shear tests are conducted on MHBS to examine the impact of hydrate saturation on the mechanical parameters and strength behaviours of MHBS. The experimental findings demonstrate that the presence of hydrate crystals enhances the robustness of the depositing medium. The stress-strain curves of MHBS have a hyperbolic shape, indicating strain hardening features. The stress-strain curves may be categorized into three distinct stages: the initial elastic deformation, followed by a slow shift to the initial yield deformation, and ultimately leading to strain hardening. As axial strain rises, the behaviour of the MHBS transitions progressively from elastic deformation to plastic deformation. The shear strength and initial yield strength of MHBS enhance with higher hydrate saturation. The reason for this is that as the hydrate saturation rises, the influence of hydrate crystals on the enhancement of sediment strength becomes more pronounced. However, the initial yield strain of each MHBS sample is between 0.5% and 1.5%, and the difference is not significant. When the hydrate saturation rises gradually, the cohesion of MHBS enhances. Nevertheless, the hydrate saturation has a very minor impact on the internal friction angle.

Phase behavior of aqueous two-phase systems formed with cholinium-based magnetic ionic liquids: Experimental insights and theoretical correlations

In this work, three cholinium-based MILs were synthesized, characterized and successfully applied to construct the magnetically responsive aqueous two-phase system (ATPs). This ATPs combined the advantages of ILs and magnetic responsiveness, and showed great potential in the field of extraction and separation. Phase behavior for the magnetic ionic liquid aqueous two-phase systems (MIL-ATPSs) containing [N 1 1n 2OH] [TEMPO-OSO3] + salts + water was investigated experimentally at different temperatures. Merchuk equation was adopted to fit the experimental binodal data with satisfactory correlation performances. The effects of the structure of MILs, temperature and types of salts on the phase behavior were evaluated. Investigation on the phase separation mechanism showed that the phase formation was affected by the structure and viscosity of MILs. The salting-out effect is recognized as the major force for phase separation, which is closely related to the Gibbs free energy of hydration (ΔhydG) and entropy of hydration (ΔhydS) of salts. In addition, a larger biphasic area was obtained by increasing the temperature, indicating the phase separation process was endothermic and entropically driven. The binodal curve at different temperature confirms that this MIL-ATPs has low critical solution temperature (LCST) phase transition behavior. All these experimentally measured data and the theoretical correlations can provide meaningful and valuable information that may promote further research and application.

Ultra-sensitive CO2 switchable low temperature transition mixture for intensified retrieval of oily waste

One of the challenge in the remediation of contaminated soil by solvent washing is the retrieval of total petroleum hydrocarbons (TPH) and solvents. Herein, a CO2 switchable hydrophobic low temperature transition mixture ([DPA][EL]) composed of ethyl lactate (EL) and dipropylamine (DPA) is proposed, accompanied by a proof-of-concept for contaminated soil washing. The path and energy of hydrogen bond interactions in [DPA][EL] were revealed by the quantum chemical calculation using the quantum theory of atoms in molecule. [DPA][EL] achieved a thorough CO2-induced polarity and hydrophobicity transition undergoing an incomplete CO2 absorption that results in the partial formation of carbonate and carbamate. [DPA][EL] was regenerated after the removal of CO2 by heating at 85 °C for 2 min. Thanks to this peculiarity, the time required for hydrophobicity transition was 197 times shorter than that of the typical CO2 switchable hydrophobic solvent, N,N-dimethylcyclohexylamine. The polarity of [DPA][EL], quantified by the normalized polarity energy, increased by 346.69 % after the introduction of CO2 because of the synergistic effect of water. This ultra-sensitive transition behavior intensified the CO2-induced separation of oily compounds, e.g., kerosene and crude oil. The conceptual usage of [DPA][EL] in the contaminated soil washing was demonstrated. The TPH content of contaminated soil decrease from 8.27 % to 0.31 % by [DPA][EL] washing through tailoring the molar ratio of DPA to EL in [DPA][EL], temperature, and [DPA][EL] to contaminated soil ratio (L/S, mL/g). [DPA][EL] whose composition possesses different polarities compensated for the poor solubility of single solvents towards TPH, thereby improving the washing efficiency of contaminated soil. Afterwards, TPH was separated upon triggered by CO2/water in 2 min, and 91.33 % of [DPA][EL] was subsequently regenerated at 85 °C in 2 min.

Exploring the brittle-to-ductile transition and microstructural responses of [formula omitted]−TiAl alloy with a crystal plasticity model incorporating dislocation and twinning

γ−TiAl alloy, with its high specific strength and creep resistance, is ideal for aerospace engines and gas turbines, but its brittleness poses significant manufacturing and processing challenges. To address these issues, this study employs a crystal plasticity finite element method incorporating dislocation and twinning to analyze the brittle-to-ductile transition behavior of γ−TiAl alloy at different temperatures. Additionally, the Bayesian optimization methods are employed to efficiently and accurately obtain parameters related to numerical calculations of crystal plasticity. The results indicate that at room temperature, the high activation resistance of the slip systems in the α2 phase leads to limited slip activity, resulting in poor plasticity. However, at 750 °C and 850 °C, the strength of the slip systems decreases significantly, allowing more α2 phase lamellae in the γ-TiAl alloy to undergo greater plastic deformation. This enhancement in the plastic deformation capacity of the α2phase lamellae reduce the overall deformation incompatibility in the TiAl alloy, thereby improving the overall ductile of the γ-TiAl alloy.