Destabilization Process Research Articles

Stability of an elongated thickness fluctuation in a horizontal soap film

Even though liquid foams are ubiquitous in everyday life and industrial processes, their ageing and eventual destruction remain a puzzling problem. Soap films are known to drain through marginal regeneration, which depends upon periodic patterns of film thickness along the rim of the film. The origin of these patterns in horizontal films (i.e. neglecting gravity) still resists theoretical modelling. In this work, we theoretically address the case of a flat horizontal film with a thickness perturbation, either positive (a bump) or negative (a groove), which is initially invariant under translation along one direction. This pattern relaxes towards a flat film by capillarity. By performing a linear stability analysis on this evolving pattern, we demonstrate that the invariance is spontaneously broken, causing the elongated thickness perturbation pattern to destabilise into a necklace of circular spots. The unstable and stable modes are derived analytically in well-defined limits, and the full evolution of the thickness profile is characterised. The original destabilisation process we identify may be relevant to explain the appearance of the marginal regeneration patterns near a meniscus and thus shed new light on soap-film drainage.

Massive stellar triples on the edge

Context. Massive stars reside predominantly in triples or higher-order multiples. Their lives can be significantly affected by three-body interactions, making it an important area of study in the context of massive-star evolution. Aims. We intend to provide a statistical overview of the lives and final outcomes of massive triples that are born dynamically stable but become unstable due to evolutionary processes. Methods. We evolved a population of initially stable triples with a massive primary star from the zero-age main sequence (ZAMS) using the code TRES, which combines stellar evolution (SE) with orbit-averaged dynamics. The triples that become unstable were transferred to a direct N-body code, where they were simulated until the system disintegrated. This excludes systems undergoing mass transfer, where the instability is caused by stellar winds or supernova explosions. We performed two suites of N-body simulations; one with gravity as the only interaction, and one with SE included. Results. We find that our triples remain on the edge of stability for a long time before disintegrating, making SE a consequential process during this phase. Eventually, the destabilisation results in either the ejection of a stellar body or the collision between two components. We find that collisions occur in 35 − 40% of systems, with the variation in this percentage coming from whether or not SE is included. The collisions predominantly involve two main sequence (MS) stars (70 − 78%) or a MS and post-MS star (13 − 28%). We estimate the Galactic rate of collisions due to massive triple destabilisation to be at 1.1 − 1.3 events per million years. Furthermore, we find that the process of destabilisation often ends in the ejection of one of the stellar bodies, specifically for 31 − 40% of systems. The ejected bodies have typical velocities of ∼6 km/s, with a tail stretching to 102 km/s. If we make the assumption that 20% of massive stars are runaway stars, then 0.1% of runaways originate from triple destabilisation. Overall, our simulations show that triple instability affects approximately 2% of massive triples. However, we estimate that up to ten times as many systems can become unstable due to mass transfer in the inner binary, and these system may end up ejecting bodies at higher velocities.

Instability of bubbly jets subjected to unrelaxed axial elastic tension

Injection of bubbly jets is a critical process in various fields, such as fuel atomization and petrochemicals. However, existing instability models for bubbly jets have predominantly focused on density variations due to bubble compressibility, largely neglecting the impact of bubbles on the macroscopic rheological properties of the mixture. In this study, we have integrated compressibility with non-Newtonian properties induced by bubbles to explore the evaluation of jet perturbations. Additionally, considering bubble pre-deformation before injection, we particularly examine the role of unrelaxed axial elastic tension in the bubbly jets. Both linear stability analysis and energy budget methods are used to illustrate the contributions of viscosity, elasticity, and compressibility. The results indicate that the viscoelastic effects induced by bubbles can significantly outweigh the effects of compressibility during the jet destabilization process. Notably, a slight unrelaxed tension can markedly increase both the perturbation growth rate and the cutoff wavenumber, potentially making it a more dominant driver of jet instability than the classical surface tension.

Cracking and deformation behaviors of overhanging rock: Laboratory tests and optical monitoring

The destabilization of overhanging rock is a dangerous geological problem. In this study, a generalized model of typical overhanging cliffs from the Three Gorges Reservoir area in China with different fracture angles, fracture lengths, and free surface depths is constructed to investigate the cracking and deformation behavior of overhanging rocks. Laboratory tests and deformation field monitoring using the digital image correlation (DIC) method are performed on these specimens to reproduce the destabilization and failure process of overhanging rock under external loading. The influence of peak load is found to be the most sensitive to the fracture length, followed by the free surface depth, and to be the least sensitive to the fracture angle. The DIC-based strain fields reveal that the fracture angle and free surface depth significantly alter the crack propagation paths, whereas the influence of the fracture length is weaker. These parameters also affect the crack initiation time. The relative displacement evolution characteristics indicate that fracture angle, fracture length, and free surface depth affect the shape and size of the rotating block, the rotation center, and the rotation pivot point and degree, respectively. The grayscale characteristic evolution trends are similar for all examined overhanging rock specimens. The evolution of the grayscale indices based on DIC can be divided into high-frequency oscillation, smooth decline (or smooth downward concavity), and stable development stages. Furthermore, the multistage properties of the indices can be used to identify the fracture state of overhanging rocks, providing a theoretical basis for graded early warning of rockfall disasters.

Spatial gradients in bank stability response in macrotidal environments: Inferences from the Severn estuary (UK)

AbstractIn this study, we present a synthetic model summarising the main sedimentary and morphologic factors that drive spatial–temporal variations in bank stability through an exemplar macrotidal estuary. In contrast to previous studies that tend to only consider localised variations in the stability of small‐scale banks, here the focus is on understanding the bank stability patterns at the scale of the whole Severn Estuary (UK). The results show that during falling tides, the bank sediments persist in a near‐saturated state giving elevated bank pore pressures that coincide in time with declines in the hydrostatic confining pressure, leading to destabilisation of the bank. In contrast, bank stabilisation predominantly occurs during rising tides when the hydrostatic confining pressure is able to dominate over the destabilisation processes. Cohesive macrotidal estuaries similar to the Severn Estuary, tend to present a generalised decrease in the instability moving from the outer estuary where the tidal oscillations are more significant, to the inner part of the system where such oscillations are reduced and coupled with less high banks.

Gap tolerance and molten pool destabilization mechanism in oscillating laser-arc hybrid welding of aluminum alloys

Oscillating laser-arc hybrid welding (O-LAHW) offers significant advantages in enhancing efficiency and mechanical properties. However, in actual production, gap fluctuations can cause instability, limiting its application in large-scale structure manufacturing. In this study, we explored the impact of gap fluctuation on the destabilization of the molten pool in aluminum alloy O-LAHW and identified the maximum gap tolerance for various conditions. High-speed photography revealed that the oscillating molten pool undergoes a transitional state of periodic collapse before complete instability, a behavior distinct from that of a non-oscillating molten pool. We also analyzed the variations in weld geometry prior to destabilization and developed a global force model of the molten pool to identify key geometrical parameters and related driving forces contributing to destabilization. The results show that maintaining a surface tension ratio of over 55 % at the root of the molten pool is crucial for its stability. Additionally, the effects of oscillatory behavior and gap variations on the laser-substrate interaction were explored, revealing the physical mechanisms behind the changes in key geometrical parameters of the melt pool cross-section. The centrifugal effect generated by high-frequency oscillation is identified as a crucial mechanism for extending the duration of periodic collapse compared to non-oscillating molten pools. By discussing the interactions between energy absorption, molten pool shape, and molten pool forces, the study reveals the evolution process of weld destabilization and explains the differences in gap tolerance between oscillating and non-oscillating laser-arc hybrid welding, providing a reference for improving weld stability.

MicroRNA Inhibiting Atheroprotective Proteins in Patients with Unstable Angina Comparing to Chronic Coronary Syndrome

Patients with unstable angina present clinical characteristics of atherosclerotic plaque vulnerability, contrary to chronic coronary syndrome patients. The process of athersclerotic plaque destabilization is also regulated by microRNA particles. In this study, the investigation on expression levels of microRNAs inhibiting the expression of proteins that protect from atherosclerotic plaque progression (miR-92a inhibiting KLF2, miR-10b inhibiting KLF4, miR-126 inhibiting MerTK, miR-98 inhibiting IL-10, miR-29b inhibiting TGFβ1) was undertaken. A number of 62 individuals were enrolled—unstable angina (UA, n = 14), chronic coronary syndrome (CCS, n = 38), and healthy volunteers (HV, n = 10). Plasma samples were taken, and microRNAs expression levels were assessed by qRT-PCR. As a result, the UA patients presented significantly increased miR-10b levels compared to CCS patients (0.097 vs. 0.058, p = 0.033). Moreover, in additional analysis when UA patients were grouped together with stable patients with significant plaque in left main or proximal left anterior descending (“UA and LM/proxLAD” group, n = 29 patients) and compared to CCS patients with atherosclerotic lesions in other regions of coronary circulation (“CCS other” group, n = 25 patients) the expression levels of both miR-10b (0.104 vs. 0.046; p = 0.0032) and miR-92a (92.64 vs. 54.74; p = 0.0129) were significantly elevated. In conclusion, the study revealed significantly increased expression levels of miR-10b and miR-92a, a regulator of endothelial protective KLF factors (KLF4 and KLF2, respectively) in patients with more vulnerable plaque phenotypes.

Should end-users take their clothes off inside on a cold winter's day? Sustainability pressures on district heating professionals in Denmark

This research explores how district heating (DH) sector professionals /employees experience the low-carbon energy transitions-related change processes in the Danish heat supply sector. Enquiry draws upon mixed data collected among DH employees from 148 utilities. Geels’ triple embeddedness framework conceptualizes the connections between regime-level actor experiences of niche- and landscape-level pressures, sustainability imperatives, and the associated change processes. This neo-institutionalist perspective finds that the historically stable DH regime-level institutions are being destabilised. It also reveals the tensions and change inertia associated with, for example, sunk costs, infrastructural path dependencies, and professional culture. For the DH professionals, and regime-level actors, these destabilization processes challenge what were previously core regime-level professional practices, skills and taken-for-granted standards for a job well done. Indeed, professional identity and pride may be at stake. Paradoxically, the identified DH sector norms for stable, affordable, and invisible heat supply service provision may not necessarily motivate DH end-users /customers towards more sustainable heat-use behaviours: DH end-users in Denmark have come to expect these DH community heat supply provision as taken-for-granted societal goods, and the topics of space heating and thermal comfort are increasingly dissociated from consumption-related debates within public, and political realms. This DH case study shows how landscape, regime, and actor-level socio-technical trajectories interact, and it exemplifies actor-structure relationships in situations of regime stress. Perhaps it proves an exemplary case for exploring the lock-in mechanisms, inertia, restraints, and potentials of change-processes within also other societal domains and institutional realms.

Vertical Track–Bridge Interaction in Railway Bridges with Ballast Superstructure: Experimental Analysis of Dynamic Stiffness and Damping Behavior

Realistic vibration predictions of railway bridges during high-speed train crossings require reliable dynamic input parameters for the applied calculation model. In particular, the dynamic stiffness and damping properties of the ballast superstructure for the mathematical consideration of the vertical track–bridge interaction (TBI) significantly influence the generated calculation results. However, due to a striking scattering of model-related characteristic values available in the literature, adequate and realistic consideration of the dynamic properties of the vertical TBI in vibration predictions is associated with considerable uncertainties. This uncertainness illustrates the need to determine experimental-based and reliable characteristic values. For targeted and isolated research of dynamic characteristics of vertical TBI, a unique large-scale test facility was developed at the Institute of Structural Engineering at TU Wien, which replicates a section of ballast superstructure on a railway bridge on a scale of 1:1 and excited to vertical movements. This paper presents the essential results and findings from the experiments, focusing on determining the ballast superstructure’s dynamic stiffness and damping characteristics, which can subsequently be implemented in practical applications for vibration predictions. As a result of the experiments, model-related dynamic stiffness and damping parameters are provided to describe the vertical TBI. In addition, the experiments are used to identify destabilization processes occurring in the ballast superstructure as a result of vertical vibrations. The investigations include the vertical TBI’s displacement and acceleration behavior and the track’s settlement behavior due to the entire structure’s vertical movements. These investigations allow for assessing the currently valid, internationally, and nationally normatively prescribed permissible accelerations for railway bridges due to train crossings. The conclusion is that short-term excessive vertical accelerations of the ballast superstructure caused by train passage do not destabilize the ballast bed or considerably change the track position.

Convective Instability Driven by Diffusiophoresis of Colloids in Binary Liquid Mixtures.

In a binary fluid mixture, the concentration gradient of a heavier molecular solute leads to a diffusive flux of solvent and solute to achieve thermodynamic equilibrium. If the solute concentration decreases with height, the system is always in a condition of stable mechanical equilibrium against gravity. We show experimentally that this mechanical equilibrium becomes unstable in case colloidal particles are dispersed uniformly within the mixture and that the resulting colloidal suspension undergoes a transient convective instability with the onset of convection patterns. By means of a numerical analysis, we clarify the microscopic mechanism from which the observed destabilization process originates. The solute concentration gradient drives an upward diffusiophoretic migration of colloids, in turn causing the development of a mechanically unstable layer within the sample, where the density of the suspension increases with height. Convective motions arise to minimize this localized rise in gravitational potential energy.

Drought-induced seismicity modulation in the New Madrid Seismic Zone, central United States

The New Madrid Seismic Zone (NMSZ) in the central United States is a seismically active intraplate region composed of two fault segments: the Reelfoot and Cottonwood Grove fault segments. It has witnessed several major earthquakes, including a devastating 1811–1812 earthquake sequence of three ~M7 events. Nearly 200 years later, earthquakes still continue today in this complex seismic zone. This seismic zone is located in a domain with higher hydrological load than surrounding regions, which may play a crucial role in seismicity modulation. However, the hydrological unloading or loading-induced seismicity modulation and the underlying earthquake dynamics on this stable plate interior remain equivocal. Our study demonstrates that increased climate variability and drought-induced hydrological unloading can be potential drivers for the crustal stress change in the upper Mississippi embayment and seismicity modulation in the NMSZ. The seismicity rate associated with the Reelfoot fault segment shows ~60% increase during drought-induced prolonged drier periods, linked to La Niña cycles, than during the relatively wetter periods. However, such a feature is lacking for the seismicity associated with the Cottonwood Grove fault segment. We argue that the near-lithostatic pore pressure condition explicitly on the Reelfoot fault segment leads to an increase in the amplitude of the velocity perturbation, making this fault segment more susceptible to seismicity modulation on a multi-annual or annual time scale by the resonance destabilization process.

A Machine Learning-Driven Approach to Uncover the Influencing Factors Resulting in Soil Mass Displacement

For most landslides, several destabilising processes act simultaneously, leading to relative sliding along the soil or rock mass surface over time. A number of machine learning approaches have been proposed recently for accurate relative and cumulative landside displacement prediction, but researchers have limited their studies to only a few indicators of displacement. Determining which influencing factors are the most important in predicting different stages of failure is an ongoing challenge due to the many influencing factors and their inter-relationships. In this study, we take a data-driven approach to explore correlations between various influencing factors triggering slope movement to perform dimensionality reduction, then feature selection and extraction to identify which measured factors have the strongest influence in predicting slope movements via a supervised regression approach. Further, through hierarchical clustering of the aforementioned selected features, we identify distinct types of displacement. By selecting only the most effective measurands, this in turn informs the subset of sensors needed for deployment on slopes prone to failure to predict imminent failures. Visualisation of the important features garnered from correlation analysis and feature selection in relation to displacement show that no one feature can be effectively used in isolation to predict and characterise types of displacement. In particular, analysis of 18 different sensors on the active and heavily instrumented Hollin Hill Landslide Observatory in the north west UK, which is several hundred metres wide and extends two hundred metres downslope, indicates that precipitation, atmospheric pressure and soil moisture should be considered jointly to provide accurate landslide prediction. Additionally, we show that the above features from Random Forest-embedded feature selection and Variational Inflation Factor features (Soil heat flux, Net radiation, Wind Speed and Precipitation) are effective in characterising intermittent and explosive displacement.

Forced labour migration as a threat to social and economic human rights and a factor of influence on the national labour market and business entities

The full-scale military invasion of the Russian Federation on the territory of Ukraine led to the emergence of a number of substantial destabilising processes and phenomena of a socio-economic nature, one of which is the strengthening of forced emigration of a substantial number of the economically active population of Ukraine. The purpose of the study was a comprehensive review and analysis of the current scientific legacy of papers devoted to the examination of the features, state, and problems of forced labour migration and identifying its impact on the national labour market and economic entities. The theoretical and methodological basis of the study as made up of general scientific heuristic methods, historiographic analysis and synthesis, comparison, and systematisation. Based on the results of the study, it was established that in the modern scientific discourse, the essence of forced labour migration is defined as a complex and dangerous socio-economic phenomenon that manifests itself in the uncontrolled movement of the population for the purpose of employment within the country and extends to other countries of the world. It was determined that most of the researchers are inclined to argue that the scale of forced labour migration has acquired threatening importance, the threatening trends of which were particularly acute during the war of the Russian Federation against Ukraine in 2022-2023, during which there is a critical increase in the volume of forced labour migration from Ukraine to European countries. There is an opinion among the scientific community that the processes of forced labour migration cause substantial problems in the national and international labour market. Most of the researchers argue that the most substantial problem caused by forced labour migration is the increase in the unemployment rate, which in Ukraine during the war reached 35% of the economically active population, which substantially unbalances the international and European labour markets, causing it to increase competition for highly paid jobs. Based on the assessment of researchers' opinions, the main ways to reduce imbalances in the development of the labour market in Ukraine and methods for minimising the risks of unemployment growth are proposed. The obtained research results can be used to create generalising reviews and more effectively work with the bibliography on the subject

Ecological dynamics in the third space: a diffractive analysis of academic development

In this article, we conceptualise the maintenance and evolution of third space practice using an ecological heuristic. This considers the dynamic balance between stabilising and destabilising processes that require third space practitioners (particularly academic developers) to be active curators of this space. These processes drive the phases of the adaptive cycle as it evolves from an epistemologically singular perspective towards one that accommodates epistemological plurality. A pictorial representation of the ecological dynamics is offered as a frame to support the construction of a personal professional narrative. This provides an exemplar of reflection on practice, and highlights the need for epistemic humility within this professional arena.

A high-resolution seismic velocity model for East Asia using full-waveform tomography: Constraints on India-Asia collisional tectonics

East Asia's complex tectonic history makes it a unique place for plate-tectonic studies. While the crust and mantle structures beneath this region have been extensively investigated by receiver function and many different kinds of tomography studies, discrepancies among seismic velocity models have complicated our understanding of East Asia's tectonic evolution. Here, we use full-waveform adjoint tomography to study the seismic P- and S-wave velocity structures of the crust and mantle beneath East Asia. We use a large waveform dataset from 141 earthquakes recorded by 4640 broadband seismic stations. Our inversion optimizes the normalized correlation coefficient between synthetic and observed seismograms within individual time windows of different seismic phases, from P arrivals to the slowest surface waves. This approach allows us to fit regional multipathed waveforms and provides very well-resolved seismic P- and S-wave velocity structures from the crust to depths of about 800 km. Furthermore, we are able to obtain this resolution over most of East Asia allowing us to compare the amplitude and shapes of anomalies across the entire region. The observed structures in our new full-waveform tomography model (FWEA23) correlate well with tectonic units, revealing sharp contrasts across tectonic boundaries. Our model reveals narrow and strong linear fast anomalies associated with subduction zones in the western Pacific and Southeast Asia. Compared to these oceanic slabs, we observe different and more complicated mantle structures beneath the India-Asia continental collision zone. While our model spans a wide region in East Asia, we focus our interpretations on the seismic velocity anomalies beneath Tibet and surrounding regions, as our model provides significant implications for India-Asia continental collision tectonics. Our analysis suggests that cratonic Indian lithosphere collided with Eurasian plate around 25–20 Ma, subsequently underthrusting beneath Tibet horizontally with little deformation. This resulted in thickening, destabilization, and delamination of the rheologically weaker and less buoyant mantle lithosphere beneath north-central Tibet. Moreover, our model reveals isolated lithospheric fragments within the mantle transition zone and lower mantle beneath southern Tibet and northern India, suggesting that non-cratonic Greater India continental lithosphere has broken off and sunk into the deeper mantle. The lack of continuity among these lithospheric fragments suggests a convective destabilization process, distinct from typical oceanic plate subduction. Our results emphasize the important role of rheological properties of continental lithospheres in shaping the dynamics of continental collision.

Unraveling the Effect of Elastic Stress on the Destabilization Process of Ni–Sn Eutectic Lamellae at an Elevated Temperature

Unraveling the Effect of Elastic Stress on the Destabilization Process of Ni–Sn Eutectic Lamellae at an Elevated Temperature

Deformation Patterns and Failure Mechanisms of Soft-Hard-Interbedded Anti-Inclined Layered Rock Slope in Wolong Open-Pit Coal Mine

Since the beginning of spring 2022, successive landslides have occurred in the eastern pit slope of the Wolong Coal Mine in Qipanjing Town, Otog Banner, Inner Mongolia, which has adversely affected the mine’s production safety. This study aims to reveal the deformation patterns and failure mechanisms of landslides. Firstly, this study establishes the stratigraphic structure of the eastern pit slope of the Wolong Coal Mine using extensive field geological surveys combined with unmanned aerial vehicle photography, drilling, and comprehensive physical exploration techniques. Indoor geotechnical tests and microscopic experiments reveal that rock mass typically exhibits the characteristics of expansibility and water sensitivity. Moreover, the mechanical parameters of the rock mass were determined using a combination of the window sampling method, the Geological Strength Index, and the Hoek–Brown strength criterion estimation theory. Finally, this study consolidates the previously mentioned insights and employs FLAC3D (7.0) software to assess the stress–strain characteristics of the excavated slope. The results indicate that the deformation mode of the Wolong open pit coal mine is the toppling failure of soft-hard-interbedded anti-inclined layered rock slopes. The unloading effect and rock expansion-induced softening lead to stress concentration at the slope corners and more substantial deformation, thereby accelerating upper slope deformation. The deformation and destabilization process of landslides is categorized into four stages: the initial deformation stage, the development stage of lateral shear misalignment, the development stage of horizontal tensile-shear damage, and the slip surface development to the preslip stage. This research offers valuable references and engineering insights for future scientific investigations and the prevention of similar slope-related geological hazards.

Investigating the wear resistance of high-chromium cast irons A532-class III-type A against high-energy abrasive particles

Regarding the widespread use of high chromium cast irons in manufacturing various industrial and mineral-processing parts such as liners, slurry pumps, and grinding balls, increasing erosion resistance is the key factor to enhance their performance. This research investigated three different chemical compositions of high chromium irons (in the eutectic and hypoeutectic range). Austenite destabilization process was conducted at two temperatures of 1060°C and 970°C followed by air cooling and then tempering at the range of 250°C to 400°C for 4 h. Erosion and bending tests were carried out on samples with optimal heat treatment conditions. Results show that the hardness of specimens heat-treated at 970°C, and also the low-carbon hypoeutectic specimens destabilized at 1060°C, increased by increasing tempering temperature over 300°C, which can be related to the formation of a higher volume fraction of M23C6 carbides. The best erosion resistance was observed in the low-carbon hypoeutectic specimen destabilized at 1060°C and tempered at 300°C. In addition, samples with higher erosion resistance exhibit lower bending strength. Finally, it was found that the principal wear mechanism was the occurrence of plastic deformation, and detachment of carbides from the surface before having an effective role in reducing wear.

Destabilization of ultra-instantaneous ultra-high-temperature sterilized milk stored at different temperatures

Ultra-instantaneous UHT (UI-UHT, > 155°C, < 0.1 s) treated milk exhibits higher retention of active protein than regular UHT milk. However, UI-UHT products demonstrate increased susceptibility to destabilization during storage. This study aimed at monitoring the destabilizing process of UI-UHT milk across different storage temperatures and uncovering its potential mechanisms. Compared with regular UHT treatment, ultra-instantaneous treatment markedly accelerated the milk's destabilization process. Aged gel formation occurred after 45 d of storage at 25°C, while creaming and sedimentation were observed after 15 d at 37°C. To elucidate the instability mechanism, measurements of plasmin activity, protein hydrolysis levels, and proteomics of the aged gel were conducted. In UI-UHT milk, plasmin activity, and protein hydrolysis levels significantly increased during storage. Excessive protein hydrolysis at 37°C resulted in sedimentation, while moderate hydrolysis and an increase in protein particle size at 25°C resulted in aged gel formation. Proteomics analysis results indicated that the aged gel from UI-UHT milk contained intact caseins, major whey proteins, and their derived peptides. Furthermore, specific whey proteins including albumin, lactotransferrin, enterotoxin-binding glycoprotein PP20K, and MFGM proteins were identified in the gel. Additionally, MFGM proteins in UI-UHT milk experienced considerable hydrolysis during storage, contributing to fat instability. This study lays a theoretical foundation for optimizing UI-UHT milk storage conditions to enhance the quality of liquid milk products.

Double-diffusive thermosolutal Hadley–Prats flow: stability analysis

ABSTRACT A mathematical model is formulated to study the onset of double-diffusion fluid flow through an infinite permeable channel with internal heat source and viscous dissipation effects under the influence of convection conditions. Numerically, the dimensionless emerging eigenvalue problem is tackled using the fourth-order Runge–Kutta scheme, specifically applied to longitudinal roll disturbances. Critical values of wave number and vertical thermal Rayleigh number are determined. A higher value of Gebhart number is observed to correlate significantly with the destabilizing phenomena in Hadley–Prats flow. Concentration-based internal heat generation also strongly modifies the critical thermal Rayleigh number. Also, it is found that the horizontal mass flow and viscous dissipation exert a substantial influence on the onset of instability in the flow regime. Linear instability analysis indicates that greater values of Lewis number in the porous medium stabilize the convection process for both values of mass diffusion parameter ( C z ) . Enhancing C z from negative to positive values diminishes the critical thermal Rayleigh ( R z ) value and consequently induces instability in the porous medium. Increased concentration-based internal heat generation generates the destabilization process in the flow region.