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Although high-temperature superconducting induction motors have a simple structure, they are distinguished by their high efficiency and high power density. However, an accurate theoretical model that defines the primary electrical characteristics controlling the motor has not been established because of the nonlinear characteristics of high-temperature superconducting squirrel-cage rotor winding. As part of establishing such a model, an experiment was conducted to analyze the relationship between the induced voltage of the rotor bar in a high-temperature superconducting squirrel-cage rotor winding and stator-side quantities (voltage and transport current), as well as its rotation characteristics. A subject was a 1.5 kW class induction motor using Bi–Sr–Ca–Cu–O high-temperature superconducting rotor bars and the experiment was performed at a temperature and a frequency of 77 K and 60 Hz, respectively. The induced voltages of the rotor bars were measured by applying a rotating magnetic field and exhibited a distorted waveform characterized by a third-order harmonic in a magnetic flux flow state. Despite the distorted voltage waveform of the rotor bar, the stator transport current responsible for driving the induction motor remained unaffected and the motor initiated rotation in a slip rotation mode. From the above results, it was experimentally clarified that a stator voltage exceeding the critical current of the rotor bar must be applied when starting the induction motor. It was also shown that the rotor bar can be regarded as a constant resistance for a constant effective value of the stator current when transitioning the motor into a slip rotation state. [ABSTRACT FROM AUTHOR]

We study the electronic spin flux (atomic-scale flow of the spin density in molecules) by a perturbation analysis and ab initio nonadiabatic calculations. We derive a general perturbative expression of the charge and spin fluxes and identify the driving perturbation of the fluxes to be the time derivative of the electron-nucleus interaction term in the Hamiltonian. We then expand the expression in molecular orbitals so as to identify relevant components of the fluxes. Our perturbation theory describes the electronic fluxes in the early stage of reactions in an intuitively clear manner. The perturbation theory is then applied to an analysis of the spin flux obtained in ab initio calculations of the radical reaction of O2 and CH3· starting from three distinct spin configurations; (a) CH3· and triplet O2 with total spin of the system set S t o t = 1 / 2 (b) CH3· and singlet O2, S t o t = 1 / 2 , and (c) CH3· and triplet O2, S t o t = 3 / 2. Further analysis of the time-dependent behaviors of the spin flux in these numerical simulations reveals (i) the spin flux induces rearrangement of the local spin structure, such as reduction of the spin polarization arising from the triplet O2 and (ii) the spin flux flows from O2 to CH3· in the reaction starting from spin configuration (a) and from CH3· to O2 in that starting from configuration (b), whereas no major intermolecular spin flux was observed in that starting from configuration (c). Our study thus establishes the mechanism of the spin flux that rearranges the local spin structures associated with chemical bonds. [ABSTRACT FROM AUTHOR]

A recombinant strain (BS168-Δ bdhA) that increased co-production of MK-7 and NK was constructed by knocking out the 2,3-butanediol dehydrogenase gene (bdhA) of Bacillus subtilis 168 to reduce the carbon spillover. The results showed that the 2,3- butanediol content in the recombinant strain was reduced by 64% to 2.76 g/L. The recombinant strain had an MK-7 production of 30.6 mg/L and an NK activity of 6.5 FU/mL. RNA-Seq analysis showed that: bdhA knockdown blocked the carbon flux of 2,3-butanediol and promoted glycerol uptake, and the carbon flux flowed more to the MK-7 and NK synthesis pathways. The negative regulator of NK, codY , was down-regulated by 2.19-fold. secA , which is responsible for the energy supply of transmembrane proteins, was down-regulated by 0.37-fold, the Tat secretion pathway was up-regulated by 2.8-fold and 0.5-fold for tatAD and tatC , respectively. This study revealed the mechanism of co-production of MK-7 and NK in recombinant strains for the first time and revealed potential molecular targets to promote the co-production of MK-7 and NK, which will provide a new strategy for metabolic engineering to increase the production of MK-7 and NK. [Display omitted] • First use of metabolically engineered commons nattokinase and NK. • bdhA knockdown promotes redistribution of carbon flow towards MK-7 and NK synthesis. • bdhA knockdown promotes extracellular secretion of MK-7 and NK. [ABSTRACT FROM AUTHOR]

We optimize jet mixing using large eddy simulations (LES) at a Reynolds number of $3000$. Key methodological enablers consist of Bayesian optimization, a surrogate model enhanced by deep learning and persistent data topology for physical interpretation. The mixing performance is characterized by an equivalent jet radius ($R_{eq}$) derived from the streamwise velocity in a plane located $8$ diameters downstream. The optimization is performed in a 22-dimensional actuation space that comprises most known excitations. This search space parameterizes the distributed actuation imposed on the bulk flow and at the periphery of the nozzle in the streamwise and radial directions. The momentum flux measures the energy input of the actuation. The optimization quadruples the jet radius $R_{eq}$ with a $7$ -armed blooming jet after around $570$ evaluations. The control input requires $2\,\%$ momentum flux of the main flow, which is one order of magnitude lower than an ad hoc dual-mode excitation. Intriguingly, a pronounced suboptimum in the search space is associated with a double-helix jet, a new flow pattern. This jet pattern results in a mixing improvement comparable to the blooming jet. A state-of-the-art Bayesian optimization converges towards this double-helix solution. The learning is accelerated and converges to another better optimum by including a deep-learning-enhanced surrogate model trained along the optimization. Persistent data topology extracts the global and many local minima in the actuation space. These minima can be identified with flow patterns beneficial to the mixing. [ABSTRACT FROM AUTHOR]

The effect of Cattaneo–Christov heat flux on hydromagnetic flow of non-Newtonian (Maxwell, Jeffrey and Oldroyd-B) fluids filled with Darcy–Forchheimer porous medium with thermal radiation, uneven heat source/sink and variable thermal conductivity is studied numerically. The mathematical problem is developed with the help of momentum, and energy equations using the suitable transformation variables. The numerical results for the transformed highly nonlinear ordinary differential equations are presented for Maxwell, Jeffrey and Oldroyd-B fluid cases. For numerical computations, an effective numerical solver namely bvp4c package is used. Effects of various controlling restrictions on the flow, and thermal fields are examined. Numerical computations for the friction factor and local Nusselt number are executed. [ABSTRACT FROM AUTHOR]

To fill the research gaps in the study of flow boiling on composite surfaces, four heat exchange tubes with different structures were investigated: an enhanced tube with herringbone teeth (EHT_HB), a tube with a dimple structure (EHT_DIM), a tube with a composite herringbone tooth/dimple structure (EHT_HB/DIM), and a smooth tube as a baseline for comparison purposes. The experimental conditions were set as follows: saturation temperature 6 °C, mass flux 50-205 kg/(m²·s), and vapor quality 0.2-0.8. After confirming the validity of the experimental results, the effects of the mass flux on the flow boiling heat transfer and pressure drop characteristics were examined. Results showed that the flow boiling heat transfer coefficient and pressure drop increase with the increase of the mass flux and the vapor quality in the tested tubes. The EHT_HB/DIM tube was found to combine the advantages of the two structures and to have the highest heat transfer coefficient. The average value of the heat transfer coefficient was found to be 43.75% higher than that of the smooth tube. Also, the average flow boiling heat transfer coefficients of the EHT_HB and the EHT_DIM tubes were found to be 15% and 35% higher than that of the smooth tube, respectively. From the perspective of the frictional pressure drop, it was found that the EHT_HB/DIM tube exhibited the maximum frictional pressure drop. The optimum working conditions of the enhanced tubes were determined by introducing a performance factor that captures the combined effects of heat transfer and pressure drop. [ABSTRACT FROM AUTHOR]

The thermal bioconvective investigation of magnetized Reiner-Rivlin nanofluid is the focus of research. The suspension of microorganisms is necessary to assess the stability of nanofluids and their consistent functioning. The heat transfer results are influenced by the radiated impact and the impacts of an external heating source. One might propose the use of the Cattaneo-Christov heat flux technique to simulate heat and mass transport difficulties. The convective boundary conditions are used for the analysis of the flow problem. The issue is modeled using a differential system. Incorporating dimensionless variables greatly simplifies the translation of the governing issue. The numerical simulation of the final system is performed using the shooting approach. The impact of settings on the thermal issue is evaluated and shown visually using graphs. Various uses of parameters in the thermal model have been presented. The heat transfer is found to increase because of the Reiner-Rivlin fluid parameter. The concentration profile decreases because of the concentration relaxation parameter. The profile of the microorganism decreases as the Peclet number increases, while the constant for Reiner-Rivlin fluid leads to increased observations. [ABSTRACT FROM AUTHOR]

In just a few decades, the normative world we inhabit is comprehensively different to the one in which S.H. Foulkes lived. As the pace, scope and content of change have transformed society, we have 'greater indeterminacy to decide our movements and identity' (p. 67). Personal identity has been released from many of its traditional moorings. The pervasive influence of contemporary 'psy-sciences' and exponential growth of therapeutic experts is one aspect of these changes. Seemingly, we live with more flux and flow than ever before. Have our theories kept up with theses fundamental changes? This paper offers a critical, post-Foulksean, post-psychoanalytic perspective on the normative world and our practices within it. It begins with history and the importance of locating who we are and what we do within the mutations of long-term change. [ABSTRACT FROM AUTHOR]

AbstractThe efficient management of thermal systems is crucial for various technological applications, necessitating innovative cooling strategies to enhance performance and reduce entropy generation. Microchannels have emerged as a promising solution due to their high heat transfer rates and compact size. This study investigates the thermofluidic characteristics and entropy generation in straight, segmental, and rib-groove microchannels utilizing de-ionized water and microencapsulated phase change slurry (MPCMS) as working fluids. Employing numerical analysis, the investigation integrates a mixture model for the base fluid and micro-encapsulated phase change material (MPCM) using an equivalent heat capacity approach to incorporate the phase transition of the MPCM (composed of paraffin with a Ti shell). Operational parameters include an inlet fluid velocity ranging from 0.575 to 3.45 m/s, heat flux varying between 15 and 30 W/cm2, and MPCM volume fractions of 5% to 20%. The ANSYS Fluent Solver, a finite volume method using a multigrid solver, was used to control the simulation by species transport. Notably, segmental channels exhibit a notable decrease in wall temperature of 29.7% and 26.3% compared to straight and rib-groove channels, respectively, under constant heat flux and flow rate. However, the effectiveness of MPCM in enhancing thermal performance was greater in straight and rib-groove channels, surpassing segmental channels by 2.5% and 3.28%, respectively, under constant heat flux. On analyzing the irreversibility, segmental channels exhibit higher frictional entropy but lower thermal entropy generation due to the fin structure, resulting in an overall reduction in total entropy generation. Moreover, segmental microchannels, when utilizing MPCMS, demonstrate superior performance in reducing irreversibility by 60.66% and 49.6% compared to straight and rib-groove channels, respectively. Total entropy generation increases with higher velocity and heat flux, while it diminishes with higher MPCM concentration across all configurations. [ABSTRACT FROM AUTHOR]

Detecting volatile organic compounds (VOCs) in exhaled breath is a promising research area for disease diagnosis. Mass transfer behavior plays a crucial role in determining the detection performance of VOCs. However, the high mobility of exhaled breath poses a substantial challenge for the mass transfer process. Here, the distinct mass transfer behavior of mobile gaseous molecules is discovered by employing the schlieren imaging technique to visualize gas flow. The results demonstrate that hollow porous structures exhibit a higher gas flow flux than solid film and microporous structures, thereby generating a sufficient probability of contact reactions for mobile gaseous molecules. The proposed colorimetric array sensors offer enhanced sensitivity and stability for detecting mobile gaseous molecules. The discovery will serve as a foundational milestone is anticipated in elucidating the behavior of gas mass transfer and promoting its potential application in disease detection through the analysis of human exhaled breath. [ABSTRACT FROM AUTHOR]

Swash flow poses a significant hazard to pedestrians standing on the slope of the seawall. Unlike the forces of overtopping flow or open channel flow on the human body, which have been studied before, swash flow has two distinct cycles within one wave period: onshore flow and offshore flow. Both cycles can risk human safety by exerting hydrodynamic forces on the body. This paper presents a numerical study to examine the hydrodynamic forces exerted on the human body when subjected to swash flow on a smooth and impermeable slope. A Reynolds-averaged Navier-Stokes (RANS) model is set up in OpenFOAM, where the numerical results are compared with experimental data obtained from wave tank tests. Reasonable agreement has been achieved, which validates the numerical model. We examine the kinematics of swash flow generated by plunging and surging breakers. In the case of a plunging breaker, we observe that the instantaneous runup height exhibited asymmetry, whereas it is nearly symmetric for a surging breaker. The velocity profile is then used to compute the momentum flux of the swash flow, which is shown to be associated with the inline forces exerted on the human body. We have defined an instability index to assess the risk of pedestrian mobilisation by swash flow, demonstrating its dependence on the Iribarren number and the body's position. The analysis reveals that the associated risk is substantially reduced as the Iribarren number increases and when the body moves towards the shoreline. [ABSTRACT FROM AUTHOR]

This paper investigates different actuator sector model implementation alternatives and how they compare to actuator line results. The velocity sampling method, tip/smearing correction, and time step are considered. A good agreement is seen between the line and sector model in the rotor plane and the wake flow. Using the sector model, it was possible to reduce the computational time by 75 % compared to the actuator line model as it is possible to run the simulations with a larger time step without compromising the accuracy considerably. The results suggest that the proposed velocity sampling method produces the closest results to the line model with different tip speed ratios. Moreover, the vortex-based smearing correction applied to the sector model results in the lowest error values, among the considered methods, to correct the radial load distributions. Also, it is seen that reducing the time step compared to the one used for the actuator disc/sector does not provide an advantage considering the increased computational time. [ABSTRACT FROM AUTHOR]

Investigation of nanofluid flow, mass and heat transfer, and impact of thermal relaxation time parameter against temperature in porous spinning rotating stretching disks was done. The behavior of heat and mass transfer, velocity, temperature and particles concentration volume fraction profiles against other parameters are investigated. A decrease in heat transfer in the lower disk and upper disk was observed as Eckert number, porosity parameter and Brownian diffusion parameter increased in value though with an increase in temperature ratio and thermal relaxation time parameter. The mass transfer rate at both lower and upper disk increased as Lewis number, Eckert number alongside porosity parameter increase in values, but decreases in value as Brownian diffusion parameter and temperature ratio increase in values. Increasing thermal relaxation time parameter caused decrease in temperature. The physical meaning is that because longer time is needed for transporting heat to nearby particles, the upper disk stretching parameter increases whenever radial velocity profile towards the lower disk is increased, which was exhibited by a negative sign towards the lower disk and positive sign in the neighbourhood of the upper disk. This implies that the fluid inside the two disks continues to flow in opposite directions of upward and downward directions. The partial differential equations which are non-linear are, transformed to non-linear coupled ordinary differential equations by app-lying Van Karman transformations which are then solved using MATLAP bvp4c with shooting technique. [ABSTRACT FROM AUTHOR]

This note describes the development and testing of a novel, programmable reversing flow 1D (R1D) experimental column apparatus designed to investigate reaction, sorption, and transport of solutes in aquifers within dynamic reversing flow zones where waters with different chemistries mix. The motivation for constructing this apparatus was to understand the roles of mixing and reaction on arsenic discharging through a tidally fluctuating riverbank. The apparatus can simulate complex transient flux schedules similar to natural flow regimes The apparatus uses an Arduino microcontroller to control flux magnitude through two peristaltic pumps. Solenoid valves control flow direction from two separate reservoirs. In‐line probes continually measure effluent electrical conductance, pH, oxidation–reduction potential, and temperature. To understand how sensitive physical solute transport is to deviations from the real hydrograph of the tidally fluctuating river, two experiments were performed using: (1) a simpler constant magnitude, reversing flux direction schedule (RCF); and (2) a more environmentally relevant variable magnitude, reversing flux direction schedule (RVF). Wherein, flux magnitude was ramped up and down according to a sine wave. Modeled breakthrough curves of chloride yielded nearly identical dispersivities under both flow regimes. For the RVF experiment, Peclet numbers captured the transition between diffusion and dispersion dominated transport in the intertidal interval. Therefore, the apparatus accurately simulated conservative, environmentally relevant mixing under transient, variable flux flow regimes. Accurately generating variable flux reversing flow regimes is important to simulate the interaction between flow velocity and chemical reactions where Brownian diffusion of solutes to solid‐phase reaction sites is kinetically limited. Article impact statement: We developed a low‐cost programmable column experiment apparatus capable of automating reversing flows a range of flux magnitudes. [ABSTRACT FROM AUTHOR]

Thin-walled bearings are widely used owing to the advantages of their light structure, high hardness, and strong load-carrying capacity. However, thin-walled bearings are often prone to deformation during the machining process, which can seriously affect the performance of the bearings. In addition, the machining deformation and quality of bearings are difficult to balance. To address the above issues, this paper investigates the effects of the machining parameters on the machining deformation, surface quality, and machining efficiency of a thin-walled bearing during the roughing stage. The dynamic balance between deformation inhibition and high quality in rough grinding was studied, and the optimal parameters for thin-walled bearing outer ring grinding were obtained. The deformation mechanism of thin-walled bearings caused by grinding was revealed through simulation and experimental analysis. The results show that the machining deformation and quality reach a balance when the workpiece speed is 55 r/min, the grinding wheel rotational speed is 2000 r/min, and the feed rate is 0.1 mm/min. Deformation increases with the increase in workpiece speed and grinding wheel speed. At the same time, the surface roughness increases with the increase in the workpiece speed, but the increase in the wheel speed will improve the surface roughness. As the workpiece speed increases, the surface topography shows a more pronounced stockpile of material, which is ameliorated by an increase in grinding wheel speed. As the rotational speed of the workpiece increases, the number of abrasive grains involved in the process per unit of time decreases, and the surface removal of the workpiece is less effective, while the increase in the rotational speed of the grinding wheel has the opposite effect. The grinding deformation of thin-walled bearings is mainly induced by machining heat and stress. As the rotational speed increases, the heat flux in the grinding zone increases. More heat flux flows into the surface of the workpiece, causing an increase in thermal stresses on the inner surface of the bearing collar, leading to greater deformation. The temperature in the grinding area can be reduced during machining, realizing a reduction in deformation. The research content contributes to the balance between high quality and low distortion in machining processes. [ABSTRACT FROM AUTHOR]

The thermal radiation and Fourier flux have drawn the attention of scientists and experts due to their extensive applications in the fields of medicine, manufacturing modern airplanes, water distillation, more efficient electronic devices, more efficient batteries, radiating treatment, and the textile industry. Through careful consideration of this, the mathematical investigation of natural convection and Fourier flux on the flow of energy and diffusion transmission of a body of cone and cylinder revolution, located in a saturated medium, has been described for the dual situations (flow over a cone and a cylinder). After then, the Runge–Kutta technique was used to explain the leading mechanism. Possessions of governing physical measures of local Nusselt and Sherwood numbers as well as velocity, thermal and diffusion figures are provided with support of tables and diagrams. It is motivating to declare that mass transfer rate is advanced in cone kind of revolution matched to cylinder kind of revolution with rising N R , N t , Q S . Also, the heat transmission rate is upper in cylinder revolution equated to cone revolution. [ABSTRACT FROM AUTHOR]

This study examined the influence of preferential flow on pore water flows and marine nitrogen transport reaction in variable saturation and variable density coastal aquifers. The 2-D unconfined aquifer model established was based on the software COMSOL by coupling the dynamic and chemical processes together. The results showed that preferential flow affects groundwater flow and salinity distribution, leading to a more complicated mixing process. The preferential flow resulted in an increase in mixing zone area and the upper saline plume area of 10.33 and 2.62m2, respectively, a decrease in saltwater wedge area of 7.22 m², and an increase in nitrate (NO3 -) removal efficiency from 7.9% to 8.97%. The NO3 - removal efficiency increases progressively with the depth (h) and quantity (n) of preferential flows; however, it decreases after a certain quantity. Further quantitative analysis revealed an increase in the intensity of nitrification and dissolved oxygen inflow flux with preferential flow depth and quantity increase. This phenomenon usually occurs on coasts where biological caves are abundant. The results also offer significant implications for designing engineering measures to mitigate saltwater intrusion and are significant to prevent groundwater quality deterioration in coastal zones. [ABSTRACT FROM AUTHOR]

Accurate modelling and prediction of sediment transport in aquatic environments is essential for sustainable coastal and riverine management. Current capabilities rely on physical process-based numerical models and fine-scale sediment flux measurements. High-resolution hydroacoustic instrumentation has emerged as a promising tool for such measurements. However, challenges arise due to the inherent complexity of ultrasound scattering processes. This study introduces a numerical modelling using a point-particle approach to simulate the echoes backscattered by such instrumentation in sediment-laden flow conditions. The model considers geometric, statistical, particle cloud, and flow-induced effects on sediment velocity, concentration, and flux estimates using an acoustic concentration and velocity profiler as a reference. The model performance is assessed here under unidirectional constant flow conditions in terms of velocity, concentration, and time-resolved sediment flux estimates for a large range of the particles' advection speed and sampled volume sizes. Application to the estimation of the measurement accuracy of sediment flux in these flows is also considered, with a final error on the flux seen to be partially controlled by the residence time of particles within the sampled volumes. The proposed model provides insights into scattering processes and offers a tool for investigating robust sediment flux estimation techniques in various flow conditions. [ABSTRACT FROM AUTHOR]

This study focuses on the hole transport layer of molybdenum trioxide (MoO3) for inverted bulk heterojunction (BHJ) organic photovoltaics (OPVs), which were fabricated using a combination of a spray coating and low-temperature annealing process as an alternative to the thermal evaporation process. To achieve a good coating quality of the sprayed film, the solvent used for solution-processed MoO3 (S-MoO3) should be well prepared. Isopropanol (IPA) is added to the as-prepared S-MoO3 solution to control its concentration. MoO3 solutions at concentrations of 5 mg/mL and 1 mg/mL were used for the spray coating process. The power conversion efficiency (PCE) depends on the concentration of the MoO3 solution and the spray coating process parameters of the MoO3 film, such as flow flux, spray cycles, and film thickness. The results of devices fabricated from solution-processed MoO3 with various spray fluxes show a lower PCE than that based on thermally evaporated MoO3 (T-MoO3) due to a limiting FF, which gradually increases with decreasing spray cycles. The highest PCE of 2.8% can be achieved with a 1 mg/mL concentration of MoO3 solution at the sprayed flux of 0.2 mL/min sprayed for one cycle. Additionally, S-MoO3 demonstrates excellent stability. Even without any encapsulation, OPVs can retain 90% of their initial PCE after 1300 h in a nitrogen-filled glove box and under ambient air conditions. The stability of OPVs without any encapsulation still has 90% of its initial PCE after 1300 h in a nitrogen-filled glove box and under air conditions. The results represent an evaluation of the feasibility of solution-processed HTL, which could be employed for a large-area mass production method. [ABSTRACT FROM AUTHOR]

Collective properties of complex systems composed of many interacting components such as neurons in our brain can be modeled by artificial networks based on disordered systems. We show that a disordered neural network of superconducting loops with Josephson junctions can exhibit computational properties like categorization and associative memory in the time evolution of its state in response to information from external excitations. Superconducting loops can trap multiples of fluxons in many discrete memory configurations defined by the local free energy minima in the configuration space of all possible states. A memory state can be updated by exciting the Josephson junctions to fire or allow the movement of fluxons through the network as the current through them surpasses their critical current thresholds. Simulations performed with a lumped element circuit model of a 4-loop network show that information written through excitations is translated into stable states of trapped flux and their time evolution. Experimental implementation on a high-Tc superconductor YBCO-based 4-loop network shows dynamically stable flux flow in each pathway characterized by the correlations between junction firing statistics. Neural network behavior is observed as energy barriers separating state categories in simulations in response to multiple excitations, and experimentally as junction responses characterizing different flux flow patterns in the network. The state categories that produce these patterns have different temporal stabilities relative to each other and the excitations. This provides strong evidence for time-dependent (short-to-long-term) memories, that are dependent on the geometrical and junction parameters of the loops, as described with a network model. [ABSTRACT FROM AUTHOR]

Regeneratively cooled scramjets are successfully used as propulsion devices in hypersonic vehicles. During operation, scramjets experience acceleration. This special process causes a dynamic flow process, and heat transfer in the cooling channel commonly occurs, which may cause hazards and control difficulties for scramjets. A dynamic numerical model with a modified heat transfer coefficient calculation method was established to study the transient flow and heat transfer processes in a cooling channel. The dynamic characteristics of the flow and heat transfer under different conditions were calculated and are discussed, including the changes in the inlet fuel mass flow, heat flux, and pressure working conditions. The results indicate that the stable time of the cooling channel outlet fuel temperature is related to the rate of change in the inlet mass flow and heat flux. The stable time of the outlet fuel temperature under decreasing heat flux working conditions was approximately 12.5 s. These results summarize the dynamic flow and heat transfer characteristics, which are significant for designing cooling channels in scramjets. [ABSTRACT FROM AUTHOR]

As a clean fuel with the advantages of abundant reserves, high calorific value, renewability, and zero carbon emissions, hydrogen has broad application prospects in the fields of energy and power. Moreover, the mixing characteristics of hydrogen and air play a crucial role in determining combustion performance. A novel mixing method of hydrogen transverse jets into an air swirl flow was investigated via numerical and experimental approaches. The Schlieren technique and high-speed photography were employed in the experiments. The effects of various swirl numbers and jet momentum flux ratios on the flow field structure, its transient characteristics, and mixing properties were studied. The research results indicate that the complex vortex structure in the mean flow field is jointly affected by the swirl number and the jet momentum flux ratio. An increase in the jet momentum flux ratio has distinct effects on the flow unsteadiness for different swirl numbers, and there exists a critical value of the jet momentum flux ratio that substantially affects the degree of mixing and a characteristic length suitable for normalization of the axial coordinates when describing the centerline concentration decay. This study provides a reference and basis for further research on combustion in air swirl flows of hydrogen transverse jets. [ABSTRACT FROM AUTHOR]

Gravity plays a crucial role in influencing bubble behavior and heat transfer in flow boiling, and its impact can vary significantly in aerospace settings. Therefore, this study aims to numerically investigate flow boiling heat transfer in a rectangular mini-channel under hyper-gravity conditions, specifically at 12 times the normal gravity. To accomplish this, a coupled volume-of-fluid and level set method is employed, taking into account fluid-solid conjugated heat transfer as well as a nucleus site density model derived from experimental data. By reproducing the flow pattern and heat transfer characteristics under different heat flux and flow rate conditions, the study unveils the effects of hyper-gravity on flow boiling heat transfer. When the flow rate is lower under hyper-gravity conditions, a notable phenomenon occurs wherein numerous bubbles detach from the heating wall and coalesce into a vapor film at the top of the mini-channel due to increased buoyancy. In contrast, under normal gravity, bubbles merge and slide on the heating wall, leading to the formation of a dry patch below. Consequently, hyper-gravity results in a lower wall superheat, and the disparity in average wall superheat between normal and high gravities escalates as the added heat flux rises. Notably, in the hyper-gravity environment, the frequent detachment of bubbles in the middle and downstream sections of the mini-channel leads to an initial increase in wall superheating, followed by a plateau along the flow direction. As the flow rate increases, the inertial force intensifies. However, intriguingly, the discrepancy in flow boiling heat transfer between normal and high gravities does not exhibit a monotonic decrease with the increasing flow rate. This behavior can be attributed to the pressing of more bubbles onto the heating wall under normal gravity, resulting in the formation of dry patches at high velocities. [ABSTRACT FROM AUTHOR]

This paper investigates the impact of the environmental conditions during the first half of the 2020 mei-yu season (Y20) and the southwest vortex (SWV), as well as their interaction, on heavy precipitation in southern Taiwan during late May 2020, based on a quantitative approach through ensemble simulations. The control experiment successfully replicates observed heavy precipitation in southern and central Taiwan and reveals a positive spatial correlation between precipitation occurrence probabilities and mean accumulated precipitation, emphasizing continuous rainfall accumulation over intermittent extreme events. Comparative analyses with sensitivity experiments elucidate that the Y20, featuring an extended western North Pacific subtropical high, intensify pressure gradients and southwesterly flow near Taiwan, favoring precipitation in windward regions but hindering it in the east. The SWV creates a moist and vortical environment near Taiwan, amplifying moisture supply and westerly winds, promoting precipitation in southern Taiwan, and enhancing frontal activity. The interaction between the SWV and the Y20, though limited in its impact on providing favorable wind and moisture conditions for precipitation southwest of Taiwan, significantly contributes to precipitation in southern Taiwan. The reason is that although the SWV primarily enhances moisture and the Y20 predominantly boost southwesterly flow, creating favorable conditions for rainfall, substantial precipitation occurs only when both factors converge in a nonlinear interaction. The interaction increases frontal activity over the Taiwan Strait and influences the movement and strength of the SWV, enhancing southwesterly flow and moisture flux in southwestern Taiwan. [ABSTRACT FROM AUTHOR]

Wastewater treatment plants (WWTPs) are one of the most important sources and sinks for per- and polyfluoroalkyl substances (PFAS). However, limited studies have evaluated short-term temporal variability of PFAS in WWTPs, particularly for their intra-day variations. For this purpose, a time-composite sampling campaign was carried out at a WWTP influent from South China for 1 week. Five out of ten PFAS were found in the influent, i.e., perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorobutane sulfonic acid (PFBS), and perfluorooctanesulfonic acid (PFOS). PFOA was the most domain PFAS whereas PFOS was detected occasionally, which might be associated with the prohibition of PFOS use in China. For the first time, we observed significant intra-day fluctuations in mass fluxes for PFOS. Different from a morning peak of pharmaceuticals reported previously, PFOS mass loads fluctuated sharply at noon and night on the weekdays. Furthermore, the mass fluxes of PFOA on the weekend were significantly elevated. For the other PFAS detected, no significant diurnal variations in mass loads were identified. Correlation analysis indicated that domestic activities (e.g., home cleaning) are likely to be the major source of these perfluorocarboxylic acids especially PFOA. In addition, flow fluxes had little effects on these PFAS mass load. These results can aid in future sampling campaigns and optimizing removal strategies for PFAS in wastewater. [ABSTRACT FROM AUTHOR]

Various researchers in the field of engineering have used porous media for many years. The present paper studies heat enhancement using two different types of porous media. In the first type, porous metal foam media was used experimentally and numerically for heat extraction. The porous medium was replaced with a porous structure using the Gyroid model and the triply periodic minimum surfaces technique in the second type. The Darcy–Brinkman model combined with the energy equation was used for the first type, whereas Navier–Stokes equations with the energy equation were implemented for the second type. The uniqueness of this approach was that it treated the Gyroid as a solid structure in the model. The two types were tested for different heat fluxes and different flow rates. A comparison between the experimental measurements and the numerical solution provided a good agreement. By comparing the performance of the two types of structure, the Gyroid structure outperformed the metal foam for heat extraction and uniformity of the temperature distribution. Despite an 18% increase in the pressure drop in the presence of the Gyroid structure, the performance evaluation criteria for the Gyroid are more significant when compared to metal foam. [ABSTRACT FROM AUTHOR]

The cryogenic hydrogen turbo-expander (CHTB) is the most core component which determines the dependability and efficiency of hydrogen liquefiers. In present study, CFD method are adopted to simulate the internal flow field inside a CHTB for a 5 t/d hydrogen liquefier. The Ω method and entropy generation method are implemented to identify vortex structures and calculate energy losses. The results show tip leakage vortex is the primary vortex and causes energy losses through strong fluid shear but not rotation effect. The turbulent dissipation is the main energy dissipation. The total entropy generation of CHTB impeller is significantly higher than nozzle because of tip clearances. As tip clearances increase from 0% to 1.6%, total entropy generation increases by 83%, and output shaft power and isentropic efficiency reduce by 9% and 6% respectively. Working conditions mainly affect the inlet angle of attack and significantly impact vortex characteristics and energy losses in the CHTB. • Modified EG model is introduced and firstly used to estimate energy loss of CHTB. • The Ω method is introduced and firstly used to identify vortex structures of CHTB. • The vortex characteristics and resultant energy dissipation are revealed. • The effects of tip clearances and working conditions are discussed and analyzed. [ABSTRACT FROM AUTHOR]

The combustion chamber baffle is an important means to suppress the combustion instability of the combustion chamber of liquid rocket engine. In order to study the influence of spray impacting on the baffle on the atomization characteristics of injector, sufficient experimental research has been carried out in this paper. In the present study, the effects of different gas/liquid flow rates and different baffle structures on the atomization characteristics are investigated. The results show that for gas-centered swirl coaxial injector, a wall film is formed on the baffle when the spray impinges on the baffle and it is broken into liquid ligaments and droplets downstream of the baffle by centrifugal force, resulting in a slower spray velocity near the baffle, a significantly larger sauter mean diameter, an increase in flow flux downstream of the baffle and worse spray uniformity. In addition, it is found that there is a spray zoning phenomena by comparing the spray with different baffles. • Three types of baffle structures were designed based on the actual combustion chamber baffle. • The phenomenon of injection zoning under the influence of different baffles was discovered. • It was found that the combustion chamber baffles should be designed to avoid inflection points on the baffle structure. • The effect of baffle structures on velocity distribution, particle size distribution, and flow flux distribution of gas-centered swirl coaxial injectors was investigated. [ABSTRACT FROM AUTHOR]

Water discharge and sediment flux variations are important parameters controlling the morphodynamic behaviour of rivers. Although quantitative estimates for water discharge and sediment flux variability are well‐constrained for modern rivers, far fewer assessments of flow and sediment flux intermittency in ancient fluvial systems from the rock record are available. In this study, a relationship between water discharge, sediment flux variability and patterns of changing fluvial stratigraphic architecture in the Middle Eocene Escanilla Formation, Spain, is explored. Water discharge intermittency factor (IWF), calculated as a ratio of the total water discharge (over the averaging time period) to the instantaneous channel‐forming water discharge if sustained for the same period, ranges from 0.03 to 0.11 in the high amalgamation intervals and from 0.10 to 0.32 in the low amalgamation intervals. Similarly, the sediment flux intermittency factor (ISF) is estimated to be in the range of 0.008 to 0.01 in the high amalgamation intervals and of 0.01 to 0.03 in the low amalgamation intervals. Consequently, high amalgamation intervals were most probably deposited under more intermittent and short‐lived intense precipitation events while low amalgamation intervals were the result of less intermittent flows spread throughout the year. Overall, these estimates are consistent with values from modern ephemeral rivers typically found in arid to semi‐arid climate and is in agreement with available proxy data for the Middle Eocene climatic context of the studied alluvial system. This highlights an important connection between hydroclimate, river morphodynamics and landscape evolution, and has implications to predict river flow and sediment transport across the Earth's surface in the geological past. [ABSTRACT FROM AUTHOR]

Dynamical ordering from a disordered plastic flow to an anisotropically ordered smectic flow induced by a dc force has been studied in various many-particle systems, including vortices in type-II superconductors. However, it remains unclear whether the dynamical ordering is a true phase transition because of lack of suitable experimental methods. Here, we study the response of vortex flow to the transverse force using a cross-shaped amorphous Mo x Ge 1 - x film. From transverse current-voltage (force-velocity) characteristics under various longitudinal currents, we find a change of the transverse response in low voltage (velocity) regions from a nonlinear to linear behavior at a well-defined longitudinal current that marks the dynamical ordering transition. We also find the scaling collapse of the transverse current-voltage curves to a universal scaling function, providing evidence of the second-order transition for the dynamical ordering transition. [ABSTRACT FROM AUTHOR]

Optimizing the structure of micromixers to improve the mixing efficiency is of great significance for chemical engineering and biology fields. In this study, an optimization of the microchannel in two liquids mixing is carried out based on computational fluid dynamics (CFD) and response surface methodology. Firstly, CFD simulations were performed to investigate the mixing flow field and mixing efficiency in the microchannel by considering different process and structure parameters (e.g., feed pressure p, microchannel width w). The response surface methodology was adopted to construct a fitting surface by CFD discrete working conditions. Then, an optimized microchannel width w was searched using the parallel particle swarm optimization (PPSO) algorithm from the response surface. Lastly, the searched optimum was validated by CFD simulation again, and the final result showed that the predicted mixing efficiency from the response surface model is well confirmed by CFD simulation. On average, the new optimized microchannel width of 1.634 mm performs higher flow flux and mixing efficiency than the original width of 1.5 mm, increasing 13.51% and 2.45%, respectively. [ABSTRACT FROM AUTHOR]

A seasonal variability in flow and sediment flux at the Socheongcho Ocean Research Station (SORS) on the west coast of Korea in 2018 was investigated to elucidate the formation of a two-layered flow structure and changes in sediment transport during stratification. An analysis of SORS data revealed stable temperatures (5–10 °C) in deeper waters, while surface temperatures rose from 6 °C in April to a peak of 30 °C in late August, gradually declining and leading to full water column mixing by late November. This temperature variation induced stratification, influencing the development of a two-layered flow structure. In winter, a singular flow structure was observed, contrasting with the emergence of a two-layered structure as stratification progressed. In the surface layer, residual currents flowed northward in summer and southward in winter, consistent with previous studies. In deeper layers, a southward residual current persisted, irrespective of the season. Sediment flux consistently moved southward, regardless of the season or water depth, with notably higher cumulative sediment flux in the deeper layer (1300 kg·m−2s−1) compared to the surface layer (300 kg·m−2s−1). These findings diverge notably from previous studies, providing new insights into ocean currents and material transport in the Yellow Sea. [ABSTRACT FROM AUTHOR]

• Sap flow of two desert species under different weather conditions is examined. • Haloxylon has stronger drought resistance than Calligonum. • Time lag between stem flow flux of two plants and environmental factors is identified. • BP neural network fits stem flow simulation of two plants with high accuracy. Understanding plant water consumption is crucial for artificial afforestation under drought environments and water stress in desert regions. However, the water consumption characteristics of desert species responding to the irrigation regimes are often neglected. By conducting a field test in the Taklimakan Desert Highway shelterbelt, this study examines the sap flow traits of two typical woody halophyte species (C alligonum mongolicum and Haloxylon ammodendron) and how they react to weather conditions and watering practices. Under the same irrigation treatment, the stem flux of C. mongolicum on sunny days was 1.5–5.3 times that on dusty days, while the stem flux of H. ammodendron on sunny days was 3.5–5.5 times that on dusty days. Both species demonstrated some sap flow during the night, representing 14.3%–24.9% and 7.3%–10.4% of the total sap flow for C. mongolicum and H. ammodendron , respectively. H. ammodendron maintained a higher stem flow during daytime and was more drought resistant than C. mongolicum. The daily sap flow patterns of these two species varied, showing both 'single' and 'double peak' curves depending on the watering conditions. A delay was also observed between the sap flow of these two species and the environmental factors. The factors influencing plant sap flow were found to be in the order of solar radiation, temperature, relative humidity, and saturated water vapor pressure difference. A BP-neural network proved highly effective for accurately simulating the sap flow of these two species. This research provides insights into how two common desert tree species adapt their water use in response to drought conditions, which is vital for artificial forest creation in desert areas. [ABSTRACT FROM AUTHOR]

We present a qualitatively investigation on the influence of thermal fluctuation on flux motion and vortex dynamic of (Li0.8Fe0.2)OHFeSe single crystals. The importance of thermal fluctuations has been assessed through the Ginzburg number Gi. The resistivity in the mixed state for (Li0.8Fe0.2)OHFeSe exhibits a thermally activated behavior investigated by TAFF theory. The field-dependent activation energy follows the relation U0 (H) ∼ H-α. The appearance of crossover at 2 T is related to the different pinning mechanisms. Single-vortex pinning occurs in the low fields range at H

The Grad's 13 distribution function was derived through a third-order Hermite polynomial expansion in terms of peculiar velocity. Recently, it has been adopted to construct a gas kinetic flux solver called G13-GKFS for simulation of flows from the continuum regime to the rarefied regime. However, this Grad's distribution function only considers the contracted polynomials that strictly satisfy orthogonality. In other words, the third-order terms of C i C 1 2 , C i C 2 2 , and C i C 3 2 share the same coefficients ( γ i ). However, the results from the discrete velocity method reveal that those coefficients could be different, especially in the rarefied regime. This may affect the accuracy of numerical results in the rarefied region. In order to consider different coefficients of the third-order terms, we propose a complete third-order polynomial expansion to approximate the distribution function in this work. To show the capability of current distribution function, a new GKFS is developed for flows from the continuum regime to the rarefied regime. Some benchmark cases are solved to demonstrate that the new GKFS outperforms the G13-GKFS in the rarefied regime. [ABSTRACT FROM AUTHOR]

Over the last decade, industrial applications and promising research domains including robotics and automotive engineering have adopted the rotary switched reluctance actuator (SRA). SRA's fault tolerance, simple, strong structure, and high-frequency operation make it popular. However, the SRA's nonlinear magnetic flux flow and saturation operation negate its benefits. Several control systems have been developed; however, they often need extensive mechanism models and advanced control theory, making them impracticable. This paper proposes a modified proportional integral derivative (PID) controller to evaluate the control performance, which comprises of PID controller with an anti-windup, a linearizer unit, and switching mechanism to activate the SRA phases. The linearizer unit aids to compensate for the nonlinear current-displacement relationship. The anti-windup element helps to halt the integral action during the starting motion. At the fully aligned position, 60°, the modified PID reduced positioning steady-state error by 4.3 times at 76.9%, overshoot by 48.8%, and settling time by 25.3%. Both the modified PID and conventional PID showed zero steady-state error at intermediate position, 70°, however the modified PID controller depicted an improved percentage overshoot by 54.5% and settling time by 74.5%. The results show that the modified PID outperforms conventional PID in transient response, steady-state error, overshoot, and settling time. [ABSTRACT FROM AUTHOR]

This paper numerically investigates the vortex and film composite cooling performance under rotating conditions. The cooling performance of the adiabatic and conjugate models is compared under the range of 0–4000 r/min. The conjugate model contains the fluid region: the cascade, the film holes, and the internal vortex cooling chamber, as well as the solid region: the blade material between the internal flow and the mainstream flow. The adiabatic model is established by removing the blade material part in the conjugate model. The dimensionless temperature θ inversely proportional to the temperature is adopted. Results show that the blade leading edge temperature doesn't vary linearly with the rotating speed. The stagnation line of the mainstream flow on the blade leading edge moves from the pressure surface to the suction surface. The maximum θ appears at 1500 r/min when the stagnation line stays certainly on the row of film holes located on the pressure surface and is 7.86% higher than the minimum θ. The minimum θ appears at 2500 r/min when the stagnation line stays on the position between the rows of film holes. The distribution of θ is much uniform, and the value of θ is much higher in the conjugate cases than the adiabatic cases due to the heat conduction through the blade material. The highest aerodynamic parameter appears at 2000 r/min due to its relatively low blade leading edge temperature and low coolant consumption and is 41% higher than the aerodynamic parameter at 0 r/min. [ABSTRACT FROM AUTHOR]

Background and Objectives Due to water resources shortage, better agricultural water using is one of the most important challenges facing the agricultural water sector. Today, the use of pressurized irrigation systems such as tape irrigation system is one of the best ways to improve agricultural water use. Due to increasing use of tape irrigation systems in row crops and the importance of understanding how to distribute moisture and salts in these irrigation methods, the purpose of this study is to use HYDRUS-2D software for simulation. The geometry of the flow and movement of water and solutes in the soil was tape irrigation method. For this purpose, while modeling the flow geometry by two-dimensional HYDRUS-2D software using observational data obtained from field experiments, hydraulic parameters and soil solute transfer were optimized by reverse solution method. Methodology The experiments were performed on corn plants in the Research Farm of the Department of Water Science and Engineering, Imam Khomeini International University, located in Qazvin. The experiment started in August 2020 and ended in mid-November after 105 days of corn growth period. Corn was cultivated in plots with an area of 9 square meters with dimensions of 3.3 meter. The distance between planting rows was 75 cm and the distance between corn seeds on the ridges was 30 cm. The irrigation tape used in the experiment was of the plate type tape and the discharge of each plate at the operating pressure of the experiment was measured as 1.3 liters per hour. The distance between the plates on the irrigation strip was 25 cm. Profile probe PR2 was used to measure soil moisture to determine the time and duration of irrigation. To do this, in the middle of each plot and to a depth of one meter, the tubes of the device were placed by using the auger. Due to the high price of the device and for economical use, high pressure polyvinyl pipes with an internal diameter of 26 mm, were used which had already been calibrated. To save and reduce the volume of operations, assuming the soil is homogeneous, harvests were made on one side of the ridge. The HYDRUS-2D software package uses the numerical solution of the Richards equation to analyze the motion of water in a porous medium in the saturated and unsaturated states. The HYDRUS-2D uses various models to estimate soil hydraulic parameters. In the mentioned model, the initial guess values of soil hydraulic parameters are estimated using a neural network paired in a model called Rosetta and soil information such as texture and percentage of its components and some moisture points in the soil characteristic curve. Findings The results showed that although HYDRUS-2D model has a high ability to simulate the movement of water in porous media, however, this issue is directly related to the accuracy of the flow geometry and the limitations of the HYDRUS-2D model regarding the definition of irrigation systems should be considered. In addition, to evaluate the accuracy of data estimates by the model, it is not enough to just check the appropriateness of statistical indicators. The estimation of the model from the soil moisture characteristic curve as well as the water balance given to the model should be controlled. In the conditions of this research, the best result was obtained when the length of nodes with variable flow boundary condition was equal to 3.14 cm. For optimizing soil hydraulic parameters, NRMSE statistical indices of 9.3%, RMSE of 0.025 (cm³ cm-3 ) and MSE of 0.00066 (cm³ cm-3 ) show excellent model simulation. In addition, the water balance given to the model by the software was calculated to be equal to 285 liters, which was close to the actual amount of water given to the ground, i.e. 253 liters. The values of the above indices for optimizing the parameters of solute transfer in soil were 22.2%, 0.17 (mg cm-3 ) and 0.028 (mg cm-3 ), respectively. Conclusion For evaluating the accuracy of the results presented by the model, it is not enough to just place the statistical indicators in the appropriate range and judge the results based on it, but also to control the initial conditions, soil moisture limits and also compare the volume of water. The data given by the model with the actual volume of water given are among the items that should be checked. Based on the results of this study, the accuracy of the water balance presented by the model is directly related to the length of nodes with variable flow conditions. Therefore, it seems necessary to study and determine the optimal length of nodes with variable flow boundary conditions before performing any simulation operation. [ABSTRACT FROM AUTHOR]

Flux pumps provide a promising solution for contactless charging of high-temperature superconducting (HTS) coils, eliminating the need for bulk current leads and reducing the heat burden for the cryogenic system. Characterizing the nonlinear effects of an HTS coil charged by a flux pump and understanding the dynamics of the charging process is essential for promoting the practical application of flux pumps. Numerical models provide a fast and cost-effective way of achieving this. In this study, we propose a methodology for coupling HTS coil and flux pump models using an electrical circuit, resulting in reduced computation costs. We validate the effectiveness of our approach against the experimental results of an HTS coil charged by a dynamo-type flux pump. Specifically, we obtain the voltage produced by the HTS dynamo using a 3D model based on the minimum electromagnetic entropy production method and apply this voltage to the load HTS coil using a T − A formulation finite-element method model coupled via an electrical circuit. The simulated charging current shows good agreement with experimental observations, validating our modeling strategy. The results demonstrate that the flux flow state in the HTS coil is the primary factor limiting the charging performance of the HTS dynamo as the charging current approaches the coil's critical current. Furthermore, based on the simulation, we demonstrate that, when using flux pumps, it is advisable to leave a margin between the operating current and the critical current of the coil. Overall, our approach has the potential to be applied to HTS coils charged by any device. [ABSTRACT FROM AUTHOR]

The present work investigates Reiner–Rivlin fluid's movement on a stretching surface with an inclined magnetic field, thermal radiation, and slip impacts. The governing equations are modeled with suitable assumptions. The governing equations are transformed into ordinary differential equations with suitable similarity terms. The numerical results are computed with the help of Runge-Kutta-Fehlberg 4th 5th order (RKF-45) and the shooting technique. The results are discussed in detail with the help of tables and graphs. The analysis mainly focuses on the different inclined angle impact over velocity and thermal profiles. The outcome reveals that the maximum thermal distribution and minimum velocity are seen with an inclined angle ξ = 90 ∘ . The cross-viscosity parameter directly impacts the velocity profile but shows a reverse trend on the thermal profile. The surface drag force is found to be minimum ξ = 90 ∘ followed by ξ = 45 ∘ and ξ = 0 ∘ . The thermal distribution rate is observed maximum at ξ = 90 ∘ than ξ = 45 ∘ and ξ = 0 ∘ . [ABSTRACT FROM AUTHOR]

Matter transport is a fundamental process in nature. Understanding and manipulating flow in a synthetic media often have rich implications for modern device design. Here we experimentally demonstrate directional transport of photons in a two-dimensional quantum walk, where the light propagation is highly tunable through dissipation and synthetic magnetic flux. The directional flow hereof underlies the emergence of the non-Hermitian skin effect, with its orientation continuously adjustable through the photon-loss parameters. By contrast, the synthetic magnetic flux originates from an engineered geometric phase, which, by inducing localized cyclotron orbits, suppresses the bulk flow through magnetic confinement. We further demonstrate how the directional flow and synthetic flux impact the dynamics of the Floquet topological edge modes along an engineered boundary. Our results exemplify an intriguing strategy for engineering directed light transport, highlighting the interplay of non-Hermiticity and gauge fields in synthetic systems of higher dimensions. Non-Hermitian phenomena such as non-Hermitian skin effect have a strong impact on open system dynamics. Here, the authors use a photonic quantum walk including a synthetic gauge field to show that the interplay of synthetic flux and dissipation enables the full control over the directional transport. [ABSTRACT FROM AUTHOR]

The discovery of nematic triplet superconductivity in doped topological insulators CuxBi2Se3 triggers interest in the identification of the d-vector of the triplet, which is related to the antinodal direction of the gap function and determines whether the superconductor is topological. We perform self-consistent analysis of the vortex state properties in a nematic spin-triplet px-wave superconductor. We first derive a Ginzburg-Landau theory to determine the shape of the vortex and vortex lattice. We find the spatial profile of the isolated vortex is elongated along the antinodal direction, and the vortex lattice is a distorted triangular lattice elongated along x, becoming square in the specific case of a small circular Fermi surface. Finally, we calculate the local density of states self-consistently for an isolated vortex and the vortex lattice using the microscopic Bogoliubov-de Gennes equation. We find that the profile of the local density of states at low in-gap energies is always elongated along the antinodal direction. Our findings are valuable for the experimental detection of the antinodal direction of the gap function in nematic triplet superconductors, and subsequently the identification of the topological character of the superconducting state as in CuxBi2Se3. [ABSTRACT FROM AUTHOR]

The novelty of this paper is to propose exact three-dimensional analytical solutions to the half infinite thermo-elastic body pressed by a rigid cylindrical structure for the first time, in which uniform heat flux flowing from rigid structure into the half infinite body is considered. Using recent general solutions expressed by four harmonic functions and extending potential theory method to consider heat effect, the governing integral equations are first derived. Then, the equations are analytically solved and displacement, stress, and temperature field components expressed by elementary functions are obtained. To validate the presented solutions, the correctness of the solutions is exactly examined, and normal contact displacement and stress without heat effect are compared with those in literatures. Furthermore, a numerical example which is the stainless steel thermo-elastic body pressed by a displacement restrictor is studied. Displacement, stress, and temperature distributions are analyzed, and the influence of heat flux on the pressed depth is also discussed in detail. The analytical solutions presented in this paper are rather important in engineering practice and can provide a basis for indentation analysis, displacement restrictor design, foundation settlement calculation, and so on. [ABSTRACT FROM AUTHOR]

The process of steam condensation in the presence of non-condensing air inside channels of Plate Heat Exchanger (PHE) is investigated based on experimental data and the results of mathematical modelling. The model consists of a system of ordinary differential equations with nonlinear right parts, solved numerically on a computer. It describes the local process parameters distribution in channel. Each of the PHE tested samples consists of four corrugated plates with three channels between them for the flow of hot and cold streams. The experimental samples have different angles of corrugations to the longitudinal plate axis (60°, 45° and 30°). The applicability of heat-momentum and heat-mass transport analogies for such channels was confirmed, as also the preservation of the Equation for the correction on effect of transverse mass flux in criss-cross flow channels. The specific form of such Equation is proposed. It allows mathematical modelling of steam-air mixture condensation using single-phase correlations for PHE channels. The intensification of overall heat transfer compared to condensation in flat wall channels is observed. It enables the decrease of PHE heat transfer area from 2 up to 4 times compared to a flat wall channel for the same process conditions. [ABSTRACT FROM AUTHOR]