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Shear spinning is a bulk forming technique used to produce hollow, rotationally symmetric parts. Although the shear spinning process has been used for the last six decades in numerous industries, in the literature, the understanding of the mechanics of the process is limited. This study provides insight into process mechanics using physical trials and numerical models. Modelling the process is challenging because of the incremental nature of the process; existing numerical models in the literature suffer from lengthy computational times and simplifications. In this study, two numerical models with different approaches to the kinematics of the spinning process are modelled with input from tests to determine friction coefficient and material properties. Then they are validated against physical trials by comparing both part geometry and strain distribution. Validated numerical models are then employed to investigate the fundamental aspects of shear spinning mechanics; evolution of strains, roller forces and part geometry in a broad range of process conditions. [ABSTRACT FROM AUTHOR]

In this paper, we revisit the classical energy transport equation for pure tidal flows in estuaries by including the effects of residual water level and freshwater discharge. Starting from the one-dimensional mass and momentum conservations, we derive analytical expressions for energy flux and its dissipation, which can be used to explore the interaction between tide and river from an energy perspective. It has been shown that the potential energy flux is dominant over the kinetic energy flux, and the energy contribution made by tide-river interaction is negligible compared with that due to tidal flow and freshwater discharge. A critical position corresponding with zero energy flux can be identified, reflecting a balance between along-channel tidal amplitude and residual water level. Assuming the variation of system energy tends to zero, we derive the long-term equilibrium bed profile with a convex-up shape, where we identify the location of a second estuarine turbidity maximum (ETM) at a position determined by the balance between river- and tide-induced energy flux. The dynamic response of tidal propagation extent and critical position with zero energy flux are shown to adjust to reflect seasonal changes towards the formation of a bed profile that is in dynamic equilibrium. [ABSTRACT FROM AUTHOR]

Polyurethane foam (P.U.) injection resin techniques have been widely used for slab crack repair, soil improvement, and structural crack repair over the past 20 years. In this study, numerical investigations were carried out to enhance the strength of both sand and clay soils via utilizing polyurethane foam as inclusion material. The investigation was conducted using 'GeoStudio (SLOPE/W) 2D' software to model 6 m high homogeneous slopes made of soft clay and medium sand with varying slope angles (25°, 30°, 35°) on same soil extended up to 9 m depth and with inclusion of polyurethane foam piles of varying diameter (0.5 m, 0.8 m), length (up to 10 m) and spacing (0.5 m, 1 m, 2 m) in the slope face. The numerical model was verified using experimental test results conducted by Hassona and Abdelnaeem (Physical and mechanical properties of polyurethane foam conditioned sand. MSc, Civil Engineering Department, Faculty of Engineering Minia University). The results revealed that, for slope angle, Ø = 30°, the factor of safety for clay soil increased when using polyurethane piles (diameter, 0.5 m and 10 m length) having spacing of two m, one m, half m, and when used as sheet piles, respectively. The factor of safety for clay soil increased significantly when using polyurethane piles (diameter, 0.8 m, and 10 m length) having spacing the same as before and as sheet piles having width of 0.5 and 0.8 m, respectively. Also, for medium dense sand soil, using polyurethane piles (diameter, 0.5 m and 10 m length) having spacing the same as before, and as sheet piles increased factor of safety much more than that for clay soil. In addition, for medium dense sand soil similar observation were noticed using polyurethane piles (diameter 0.8 m, and 10 m length) having spacing the same as before, and as sheet piles, respectively. In addition, the effects of slope angles also studied. [ABSTRACT FROM AUTHOR]

This study investigates the influence of various transverse reinforcement configurations on the torsional performance of glass fiber reinforced plastic (GFRP) reinforced concrete beams. A comprehensive experimental investigation includes five specimens, each characterized by unique transverse reinforcement designs in terms of stirrup spacing and inclination angles. The implementation of transverse torsional reinforcements within the beams exhibited a remarkable post-cracking hardening response, contributing to enhanced strength recovery. The experimental findings are subsequently compared with a reliable three-dimensional finite element model developed using the ABAQUS software. Finally, a parametric study is conducted to examine the influence of concrete and GFRP bar strength, along with longitudinal and transverse reinforcement ratios, on the torsional behavior of GFRP reinforced concrete beams. The results emphasize the significant impact of concrete tensile strength and transverse reinforcement on the cracking torque, while the parameters related to longitudinal reinforcement have only marginal effects. [ABSTRACT FROM AUTHOR]

Cloud condensation and hydrometeor evaporation fractionate stable isotopes of water, enriching liquid with heavy isotopes; whereupon updrafts, downdrafts, and rain vertically redistribute water and its isotopes in the lower troposphere. These vertical water fluxes through the marine boundary layer affect low cloud climate feedback and, combined with isotope fractionation, are hypothesized to explain the depletion of tropical precipitation at higher precipitation rates known as the "amount effect." Here, an efficient and numerically stable quasi‐analytical model simulates the evaporation of raindrops and enrichment of their isotope composition. It is applied to a drop size distribution and subcloud environment representative of Atlantic trade cumulus clouds. Idealized physics experiments artificially zero out selected processes to discern the separate effects on the isotope ratio of raindrops, of exchange with the environment, evaporation, and kinetic molecular diffusion. A parameterization of size‐dependent molecular and eddy diffusion is formulated that enriches raindrops much more strongly (+5‰ for deuterated water [HDO] and +3.5‰ for H218 ${\mathrm{H}}_{2}^{18}$O) than equilibrium evaporation as they become smaller than 1 mm. The effect on evaporated vapor is also assessed. Rain evaporation enriches subcloud vapor by +12‰ per mm rain (for HDO), explaining observations of enriched vapor in cold pools sourced by evaporatively cooled downdrafts. Drops smaller than 0.5 mm evaporate completely before falling 700 m in typical subtropical marine boundary layer conditions. The early and complete evaporation of these smaller drops in the rain size distribution enriches the vapor produced by rain evaporation. Plain Language Summary: Heavy water isotopes, whose hydrogen or oxygen atoms hold an extra neutron or two, condense more and evaporate less than the common water isotope (H216 ${\mathrm{H}}_{2}^{16}$O). Variations of those heavy isotopes in precipitation tell a story about present weather conditions and how climate has changed in the past. Records of rainfall that fell to the surface are affected by the exchanges between vapor and rain as it evaporates below the clouds. Here, a simple model of evaporating rain explains how the amount of heavy isotopes in rain changes between the cloud and the surface. The fraction of heavy isotopes changes because they evaporate less, yet also because the heavy water molecules diffuse away from evaporating raindrops more slowly than the lighter water molecules. One notable prediction of our model is that this molecular diffusion causes larger changes in small raindrops than previously thought, especially as they approach complete evaporation. These variations have been observed near Barbados in "cold pools"—gusts of air, cooled by the evaporation of rain, spreading out across the surface. Key Points: Evaporated vapor from trade cumulus rain is near the rain's initial isotope ratio and strongly enriched compared to surrounding vaporRain isotope composition equilibrates to surrounding environmental vapor as it falls 10s of metersBefore the smallest raindrops evaporate completely, molecular diffusion enriches them 40% more strongly than millimeter‐sized drops [ABSTRACT FROM AUTHOR]

A ready-to-use numerical model has been developed for the atomic ladder (cascade) systems which are widely exploited in Rydberg Radio Frequency (RF) sensors. The model has been explicitly designed for user convenience and to be extensible to arbitrary N-level non-thermal systems. The versatility and adaptability of the model is validated up to 4-level atomic systems by direct comparison with experimental results from the prior art. The numerical model provides a good approximation to the experimental results and provides experimentalists with a convenient ready-to-use model to optimise the operation of an N-level Rydberg RF sensor. Current sensors exploit the 4-level atomic systems based on alkali metal atoms which require visible frequency lasers and these can be expensive and also suffer from high attenuation within optical fiber. The ability to quickly and simply explore more complex N-level systems offers the potential to use cheaper and lower-loss near-infrared lasers. [ABSTRACT FROM AUTHOR]

The rate of spontaneous action potentials (APs) generated by sinoatrial node cells (SANC) is regulated by local Ca2+ release (LCR) from the sarcoplasmic reticulum via Ca2+ release channels (ryanodine receptors, RyRs). LCR events propagate and self-organize within the network of RyR clusters (Ca release units, CRUs) via Ca-induced-Ca-release (CICR) that depends on CRU sizes and locations: While larger CRUs generate stronger release signals, the network's topology governs signal diffusion and propagation. This study used super-resolution structured illumination microscopy to image the 3D network of CRUs in rabbit SANC. The peripheral CRUs formed a spatial mesh, reflecting the cell surface geometry. Two distinct subpopulations of CRUs were identified within each cell, with size distributions conforming to a two-component Gamma mixture model. Furthermore, neighboring CRUs exhibited repulsive behavior. Functional properties of the CRU network were further examined in a novel numerical SANC model developed using our experimental data. Model simulations revealed that heterogeneities in both CRU sizes and locations facilitate CICR and increase the AP firing rate in a cooperative manner. However, these heterogeneities reduce the effect of β-adrenergic stimulation in terms of its relative change in AP firing rate. The presence of heterogeneities in both sizes and locations allows SANC to reach higher absolute AP firing rates during β-adrenergic stimulation. Thus, the CICR facilitation by heterogeneities in CRU sizes and locations regulates and optimizes cardiac pacemaker cell operation under various physiological conditions. Dysfunction of this optimization could be a key factor in heart rate reserve decline in aging and disease. [ABSTRACT FROM AUTHOR]

A scientific and reasonable microseismic monitoring sensor network is crucial for the prevention and control of rockmass instability disasters. In this study, three feasible sensor network layout schemes for the microseismic monitoring of Sanshandao Gold Mine were proposed, comprehensively considering factors such as orebody orientation, tunnel and stope distributions, blasting excavation areas, construction difficulty, and maintenance costs. To evaluate and validate the monitoring effectiveness of the sensor networks, three layers of seismic sources were randomly generated within the network. Four levels of random errors were added to the calculated arrival time data, and the classical Geiger localization algorithm was used for locating validation. The distribution of localization errors within the monitoring area was analyzed. The results indicate that when the arrival time data are accurate or the error is between 0% and 2%, scheme 3 is considered the most suitable layout; when the error of the arrival time data is between 2% and 10%, scheme 2 is considered the optimal layout. These research results can provide important theoretical and technical guidance for the reasonable design of microseismic monitoring systems in similar mines or projects. [ABSTRACT FROM AUTHOR]

Deformation predictions in high Concrete Face Rockfill Dams tend to underestimate observed settlements due to scale effect and breakage phenomena that cannot be adequately captured by laboratory tests. This paper presents a Visco-Elasto-Perfectly Plastic (VEPP) model for predicting deformations in high Concrete Face Rockfill Dams (CFRDs) that addresses these challenges incorporating explicitly key rockfill parameters like grain size and post-compaction porosity, which influence both the non-linear elastic and plastic behaviors of rockfill. The VEPP model enables deformation prediction while using standard laboratory test results. The model's effectiveness was demonstrated through its application to the 233 m high Shuibuya Dam, the tallest CFRD in the world. The VEPP model predictions closely align with observed deformations throughout the dam's construction, impoundment, and early operational stages. By using physically meaningful parameters, the model reduces the uncertainty associated with the empirical assessment of model parameters using back-analysis from similar projects. While the VEPP model offers improved predictive accuracy, particularly during early design phases, further advancements could be achieved by refining the creep formulation and accounting for grain size evolution during construction. This approach has the potential to optimize the design and construction of future high CFRD. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) enables the production of complex geometries that are not accessible by conventional processes. Fused deposition modeling (FDM) 3D printing is an important choice for many industries, particularly for additive manufacturing of microelectronic systems. The various physical properties of printing polymer materials, such as geometry, rheological behavior, and others, need to be taken into account in the printing process. In our study, a semi-crystalline polypropylene polymer PP is used in the FDM process, as it is characterized by deformability due to crystallization. We investigate the thermomechanical behavior of a semi-crystalline polymer PP (polypropylene) with different material deposition geometries ranging from a parallelepiped filament to a cylindrical filament in a numerical model developed. A coupling (to temperature vs. time evolution during printing) of solid mechanics, heat transfer, and crystallization kinetics equations was considered to build the Multiphysics numerical model capable of predicting temperature profiles, residual stresses, and degree of crystallization during the FDM process. The results obtained with the numerical model provide a reliable approach to predicting and adjusting the actual thermomechanical behavior of a printed electronics package. The values are calculated and compared to the six points in the two samples. The results show that the change in deposit shape resulted in a maximum deviation of 3.3 MPa for residual stress and 0.376 for the degree of crystallization, while a decrease was observed in the selected points with an average deviation of 1.81 MPa and 0.193 for residual stress and the degree of crystallization, respectively. This is due to the effects of the modification of the shape model on the temperature profile model, with the change in the 3D structures of the printed polymer material; the methodology presented in this paper allows the numerical model to be validated with an experimental study of the literature. The paper proposes future work and an experimental study to validate the results of the numerical model. [ABSTRACT FROM AUTHOR]

Silicon carbide (SiC) is a widely used component for thermal protection system (TPS) design. This material is often used either as a coating layer to protect beneath carbon‐based material against oxidation or as a ceramic matrix for composite materials used in the hypersonic leading edges. A numerical equilibrium model for SiC‐coated material ablation is developed in this study to compute the material response of coated TPS in hypersonic relevant aerothermal environment. The developed model is based on an equilibrium approach similar to the carbon graphite oxidation framework for ablative charring materials. The equilibrium wall composition is calculated based on the minimization of the Gibbs free energy. The proposed method can capture numerically the transition from passive to active oxidation while maintaining a low computational cost and good numerical stability. Implementation of the model in the Porous Material Analysis Toolbox based on OpenFOAM code permits to compare against previous literature test cases. By comparing the surface temperature obtained from the model with the experimental data, it is observed that the numerical model gives a good estimation providing accurate surface temperature prediction. [ABSTRACT FROM AUTHOR]

Managed aquifer recharge (MAR) is increasingly being adopted worldwide to mitigate groundwater depletion and ensure the sustainability of water resources. Rainwater harvesting (RWH)-MAR can augment aquifer storage and reduce flood damage in rural areas with dense greenhouse facilities. This study has assessed the feasibility of greenhouse RWH-MAR in Namwon agricultural areas in the southern part of Jeju Island, South Korea, by considering the injection rate and location of MAR using a numerical model. The model results showed that groundwater level increases were directly related to the infiltration rate, although spatial differences in head rise were observed owing to the spatial variability of hydraulic conductivity. In addition, installing the RWH-MAR in highland areas (>100 masl) enhanced the water level rise when compared to the expected values, indicating that a higher hydraulic gradient and thick unsaturated zone facilitated more effective MAR outcomes than in lowland areas. To optimize the contribution of source water to the agricultural water demand, placing the RWH-MAR near the pumping well improved the availability of injected rainwater to agricultural wells. This study highlights the importance of designing RWH-MAR schemes considering MAR objectives and the topographic and hydrogeological characteristics of the site. [ABSTRACT FROM AUTHOR]

In metal cutting, a large amount of mechanical energy converts into heat, leading to a rapid temperature rise. Excessive heat accelerates tool wear, shortens tool life, and hinders chip breakage. Most existing thermal studies have focused on dry machining, with limited research on the effects of cutting fluids. This study addresses that gap by investigating the thermal behavior of cutting tools during continuous and interrupted turning with cutting fluid. Tool temperatures were first measured experimentally by embedding a thermocouple in a defined position within the tool. These experimental results were then combined with simulations to evaluate temperature changes, heat partition, and cooling efficiency under various cutting conditions. This work presents novel analytical and numerical models. Both models accurately predicted the temperature distribution, with the analytical model offering a computationally more efficient solution for industrial use. Experimental results showed that tool temperature increased with cutting speed, feed, and cutting depth, but the heat partition into the tool decreased. In continuous cutting, cooling efficiency was mainly influenced by feed rate and cutting depth, while cutting speed had minimal impact. Interrupted cutting improved cooling efficiency, as the absence of chips and workpieces during non-cutting phases allowed the cutting fluid to flow over the tool surface at higher speeds. The convective cooling coefficient was determined through inverse calibration. A comparative analysis of the analytical and numerical simulations revealed that the analytical model can underestimate the temperature distribution for complex tool structures, particularly non-orthogonal hexahedral geometries. However, the relative error remained consistent across different cutting conditions, with less error observed in interrupted cutting compared to continuous cutting. These findings highlight the potential of analytical models for optimizing thermal management in metal turning processes. [ABSTRACT FROM AUTHOR]

Although Ceramics are well known for some of their excellent properties such as high hardness, thermal and chemical resistance, wear resistance and high strength, they are also limited in terms of machining due to hardness. Electro discharge machining has its upper hand when it comes to ceramics machining due to its noncontact and no force nature machining. However, for any materials to qualify for the electro-discharge machining, there is minimum requirement of electrical conductivity. Ceramics doped with conductive particles can be machined using EDM, whereas nonconductive ceramics needs assistive electrode EDM. While, material removal mechanism of conductive materials is predominately melting and evaporation, for non-conductive ceramics mechanism are mostly thermal spalling, melting, and evaporation This study aims to model the material removal rate and surface roughness associated with electro discharge machining of non-conductive machining. Proposed model is based on removal due to melting in multi discharge manner. Although model only considers removal due to melting, it is shown that it is agreeable to experimental results in a reasonable margin. [ABSTRACT FROM AUTHOR]

This study concentrates on numerically evaluating the behavior of a floating body with a box format. Although research on floating objects has been conducted, the numerical modeling of Wave Energy Converter (WEC) devices, considering the effects of fluctuations, remains underexplored. Therefore, this research intends to facilitate the analysis of floating devices. First, the experimental data served as a benchmark for evaluating the motion paths of the floating box's centroid. Second, the effects of various wave periods and heights on the floating body's movement were analyzed. The Volume of Fluid (VOF) multiphase model was applied to simulate the interactions between phases. The computational model involved solving governing equations of mass conservation, volumetric fraction transport, and momentum, employing the Finite Volume Method (FVM). The validation demonstrated that the Normalized Root Mean Square Error (NRMSE) for the x/h ratio was 3.3% for a wave height of 0.04 m and 4.4% for a wave height of 0.1 m. Moreover, the NRMSE for the z-coordinate to the depth of water (z/h) was higher, at 5% for a wave height of 0.04 m and 5.8% for a wave height of 0.1 m. The overall NRMSE remained within acceptable ranges, indicating the reliability of the numerical solutions. Additionally, the analysis of horizontal and vertical velocities at different wave periods and heights showed that for H = 0.04 m, the wave periods had a minimal impact on the amplitude, but the oscillation frequency varied. At H = 0.1 m, both velocities exhibited significantly larger amplitudes, especially for T = 1.2 s and T = 2.0 s, indicating stronger motion with higher wave heights. [ABSTRACT FROM AUTHOR]

The three-piece oil control ring (TPOCR), traditionally used in light-duty gasoline engines, is becoming a viable option for heavy-duty gas and hydrogen engines due to its ability to control lubricating oil consumption (LOC) under throttled conditions. Understanding the distribution of oil inside the TPOCR groove, as well as the effects of rail gap and drain hole positions, is critical for optimizing TPOCR and groove designs. In this work, a one-dimensional oil distribution model was developed to simulate inertia-driven oil transport in the TPOCR groove. A novel approach was proposed by first dividing the TPOCR into units composed of a pair of expander pitches. Then, the relationship between the oil outflow rate of the unit and its oil mass was established with the help of three-dimensional two-phase computational fluid dynamics (CFD) simulations. This relationship was then used to model one-dimensional oil transport along the circumference of the TPOCR groove. Incorporating the boundary conditions at the rail gaps and drain holes, this simple model can complete computations for 10,000 cycles within a few seconds, allowing for quick the evaluation of transient behavior and design iterations. Studies on low-load conditions show that the model, with reasonable adjustment for the boundary conditions, can match the oil distribution patterns observed in visualization experiments. This is the first step toward studying oil transport in the TPOCR groove before involving the effects of gas flows. [ABSTRACT FROM AUTHOR]

The asphalt aging model is a crucial module in the Mechanistic-Empirical (ME) pavement design programme for asphalt pavement performance prediction. In this study, an analytical aging model that couples diffusion and kinetics aging model (CDKAM) is improved to analyze and predict the field aging of asphalt pavements. The complex modulus (E*) of field cores was used as the aging property to illustrate the derivation of explicit expressions of time-averaged thermal source term ( $ \overline {TST} (t) $ TST ¯ (t)) and time-averaged diffusion coefficient ( $ \bar{D}(t) $ D ¯ (t)). The value of the material-related parameter (M) in $ \overline {TST} (t) $ TST ¯ (t) model differs among different mixtures, which could assess the mixture's susceptibility to thermal oxidation. The CDKAM with $ \overline {TST} (t) $ TST ¯ (t) and $ \bar{D}(t) $ D ¯ (t) was used to predict E* of field aging for asphalt pavements in Texas after 22-month service life. The calibrated CDKAM could reasonably quantify the aging extent over time and the aging gradient over depth for studied asphalt pavements. [ABSTRACT FROM AUTHOR]

The thermal recovery is facing the challenge of improving quality and efficiency. Steam-assisted gravity drainage (SAGD) steam circulation has a profound implications for the formal production. There is a lack of research on the situation when the steam injection pressure of injection well is lower than that of production well during startup stage. In this paper, the effects of diverse injection pressure difference on SAGD steam circulation and production stage are investigated by analytical modeling and numerical simulation, especially when the steam injection pressure of producer well is larger than that of injection well, and reliable results are obtained by temperature falloff test and model comparison validation. Meanwhile, in order to minimize the factors affecting the simulation accuracy, a sensitivity analysis of the temperature prediction model for the startup stage is carried out using Monte Carlo method and the finest possible mesh is used in the numerical simulation. The results show that:①The preheating results are faster and more uniform than the conventional preheating method when steam injection pressure of producer is greater than that of injector, and the subsequent production indexes are also superior to those of the conventional preheating method. ②The injected steam temperature had the greatest effect on the prediction accuracy of the analytical model; The finer the numerical simulation grid division, the lower the midpoint temperature of the horizontal well pair; ③An optimal range of injection pressure differences that achieves the best balance between preheating efficiency and thermal recovery effectiveness is achieved with Pprod-Pinj in the range of 400–500 kPa. ④The preheating method investigated in this paper minimizes the effect by unfavorable factors such as reservoir non-homogeneity, which holds the potential for more uniform, time-saving preheating and without the addition of field equipment. [ABSTRACT FROM AUTHOR]

Yarn breakage or ends-down in ring spinning adversely affects spinning efficiency. An ends-down event may continue for an extended period of time before it is detected and attended to. This study explored a novel approach to detect yarn breakage or ends-down in ring spinning, through changes in ring temperature after an ends-down. Numerical simulation and experimental verification were used to examine the ring temperature changes during the yarn breakage process. The results showed that higher ambient temperature, spindle speed and yarn count (tex) resulted in a higher ring temperature and a longer ring cooling time. But the rate of ring temperature decrease immediately after yarn breakage was quite high, dropping 50% between equilibrium and ambient temperatures in approximately 16 s for most spinning conditions. The model and results of this study offer the basis for a new yarn breakage detection option in ring spinning based on the temperature change of the ring. [ABSTRACT FROM AUTHOR]

Analyses of global climate model results for urban impacts on temperature and precipitation are rare. Previous analyses of the global Conformal Cubic Atmospheric Model simulation results for 1985–2010 have revealed urban effects on minimum and maximum temperatures. Using the same dataset to derive time‐zone‐corrected three‐hourly local time period (LTP) data, averaged diurnal cycles of temperature and precipitation were calculated for grid cells with greater than 10% urban fraction (urban grid cells) globally. Three latitudinal bands were assessed: northern extratropics (NET, 274 urban grid cells), southern extratropics (SET, 39 urban grid cells), and the Tropics (26 urban grid cells). The largest statistically significant urban influences on temperature are consistently found at night, in agreement with many previous studies on urban heat islands. Signs of urban cooling were found for a few hours, from 09:00 to 15:00 LTP, most often in summer. Influences of urban areas on precipitation varied, with small increases and decreases in all latitudinal bands and seasons. For NET, increases were generally found. In the Tropics, increases were found from 21:00 to 09:00 LTP for all seasons except DJF, with decreases for all seasons from 15:00 to 18:00 LTP. In SET, all seasons had increases for 21:00 to 00:00 LTP and decreases for 15:00 to 18:00 LTP. DJF had decreases for all LTPs except 21:00 to 00:00 LTP and SON had increases for all times except 15:00 to 18:00 LTP. Differences in rainfall in the region surrounding the urban areas were broadly similar to local changes in NET. For the Tropics and SET, regional decreases were found for DJF and JJA, with a more varied pattern for other months. Regional effects appeared to be more restricted to near‐urban areas in the Tropics than in NET. The results indicate some influence of nearby urban areas on regional temperature and precipitation. [ABSTRACT FROM AUTHOR]

Composite tubes are widely adopted in engineering protections owning to desirable passive energy absorption. With the aim of enhancing energy absorption and making full use of structural materials, a novel tube inspired by the structure of cattle horn has been designed. It consisted of a shell composed of nested tubes and a core composed of evenly distributed tubes, which are connected by beams. The energy absorption properties of bionic tube, six-cell tube, four-cell tube and circular tube were compared by numerical models verified by axial compression. The factors affecting mechanical responses and energy absorption capacities of bionic tube were analysed. Compared to the six-cell tube, the bionic tube exhibited a 104.91% increase in peak load, a 239.51% increase in mean load and an 83.39% increase in specific energy absorption. Under the premise of ensuring the energy absorption, mean load and crushing force efficiency, the mass and peak load can be controlled by limiting the wall thickness and height of core. The proposed bionic tube had the potential to be applied in the automobile and aerospace industry. [ABSTRACT FROM AUTHOR]

Abstract—Variations in the position of the dome of Weddell Sea Deep Water was studied based on the EN4 data on temperature and salinity for monthly mean conditions in February and August in 1993–2012 depending on the wind friction stress calculated according to the JRA55-do data. The dome itself is considered in the region 60°–67° S and 10°–25° W. The range of potential temperatures in the layer of Weddell Sea Deep Water is 0.02-0.20°C. Observed mean data of the dome of isotherms and isopycnals in February from 1993 to 2012 is formed as a sequence of the intensification of the thermohaline circulation in general and the wind circulation of water in the Weddell Sea. Isotherms experience periodic rise and descent under the influence of seasonal variability of the cyclonic nature and the intensity of the wind field. The outflow of deep water from the Weddell Sea mainly occurs through the Orkney Passage over a transverse ridge of about 3600 m deep. Depending on the rise or descent of the isotherms around this passage, warmer or colder Antarctic Bottom Waters enter the Scotia Sea. [ABSTRACT FROM AUTHOR]

Using the images of the Sentinel-1A satellite, taken from May 1 to September 22, 2023, and the differential interferometry method (DInSAR) we calculated successive displacement fields in time, which clearly show a dome-shaped uplift on the western slope of Shiveluch volcano, 8‒8.5 km west of its active crater. The uplift grew especially intensely at the satellite acquisition intervals of May 1‒13, 2023; May 13‒25, 2023; and May 25‒June 6, 2023. To confirm the hypothesis on the formation of the displacement region due to magma intrusion beneath the western slope of the volcano, numerical modeling was carried out and the parameters of the sill-like magma body, which forms the displacements on the surface that best match the displacement observed from satellite radar interferometry data, were determined. It is assumed that, after the eruption on April 11, 2023, magma rose from a depth of 20‒25 km through a fissure formed under the western slope of the volcano and intruded horizontally beneath the slope at a depth of 1‒2 km in the north-northwesterly direction. Within the precision of data on slope displacements, the size of the magma body varies from 6.0 × 3.0 km at 1 km depth to 5.25 × 1.4 km at 2 km depth, while its height ranges from 0.5 to 1.75 m and its volume, from 0.009 to 0.0129 km3. Thus, based on radar interferometry data together with the data on the distribution of seismic activity accompanying the movement of magma, the model of the magma body that intruded beneath the western slope of Shiveluch volcano in the postparoxysmal phase of the eruption on April 11, 2023, was constructed. The formation of a new extrusive dome on the western slope of Shiveluch volcano at the end of April 2024 confirms the hypothesis about the intrusion of magmatic material beneath the western slope of the volcano and allows estimating the rate of magma rise to the surface. [ABSTRACT FROM AUTHOR]

The growth in population increases greenhouse gas (GHG) emissions into the environment. High GHG emissions are attributed to meat production, due to its high energy demand. The largest carbon footprint in the production of poultry meat is generated by combustion. This paper deals with the problem of greenhouse gas emissions (total dust, CO, CO2, NOx, SOx and benzo(a)pyrene) resulting from the generation of energy for heating broiler houses located in different locations in Europe. The study includes continuous measurements of selected microclimate parameters: temperature and relative humidity inside and outside the building, floor temperature, wind speed and direction, and solar radiation intensity. Validation and calibration of the model, emission calculations, and analysis of the obtained results were conducted. Eighteen design variants were assumed, differentiated by the heating fuel used (hard coal, fuel oil, gaseous fuels), material and construction solutions for the floor and the location of the facility. The analysis showed that CO2 emissions for a facility located in northern Europe are 123,153 kg higher compared to the same building located in southern Europe. In addition, increasing the floor's thermal resistance by 3.69 m2·K·W−1 reduced harmful gas emissions by an average of 5.7% for each of the locations analysed. [ABSTRACT FROM AUTHOR]

Cancer invasion and migration play a pivotal role in tumor malignancy, which is a major cause of most cancer deaths. Rotating magnetic field (RMF), one of the typical dynamic magnetic fields, can exert substantial mechanical influence on cells. However, studying the effects of RMF on cell is challenging due to its complex parameters, such as variation of magnetic field intensity and direction. Here, we developed a systematic simulation method to explore the influence of RMF on tumor invasion and migration, including a finite element method (FEM) model and a cell-based hybrid numerical model. Coupling with the data of magnetic field from FEM, the cell-based hybrid numerical model was established to simulate the tumor cell invasion and migration. This model employed partial differential equations (PDEs) and finite difference method to depict cellular activities and solve these equations in a discrete system. PDEs were used to depict cell activities, and finite difference method was used to solve the equations in discrete system. As a result, this study provides valuable insights into the potential applications of RMF in tumor treatment, and a series of in vitro experiments were performed to verify the simulation results, demonstrating the model's reliability and its capacity to predict experimental outcomes and identify pertinent factors. Furthermore, these findings shed new light on the mechanical and chemical interplay between cells and the ECM, offering new insights and providing a novel foundation for both experimental and theoretical advancements in tumor treatment by using RMF. [ABSTRACT FROM AUTHOR]

The factors that influence the symmetry of an imploding detonation are investigated experimentally and theoretically. Detonations in sub-atmospheric acetylene–oxygen were initiated and made to converge in an apparatus that followed that of Lee and Lee (Phys Fluids 8:2148–2152, 1965). The width of the test section was controlled with a wave-shaping insert, which formed the test section against the viewing window, creating an effectively two-dimensional problem with a channel width comparable to the detonation cell size. The convergence of the detonation was observed via self-luminous open-shutter photography and high-speed videography. The resulting videos were analyzed to quantify the wave speed, degree of asymmetry, and direction and magnitude of the offset in the center of convergence. To determine the experimental parameters that influence the symmetry of the imploding wave, the wave-shaping insert was intentionally canted by 0. 3 ∘ -- 0. 6 ∘ , accentuating the asymmetry of the imploding detonation. The experiment was modeled using a Huygens construction wherein the detonation is treated as a collection of wavelets, each assumed to propagate locally at a velocity determined by the channel width. The results of the model reproduced the observed offsets in detonation convergence from the center of the apparatus, confirming that velocity deficits resulting from the narrow channel width control the observed asymmetry. [ABSTRACT FROM AUTHOR]

Spillway is a hydraulic structure designed to release of excess water, from the upstream to the downstream area of a dam. In the present study, a three-dimensional numerical model was employed using Flow-3D software. The accuracy of the model was verified through experimentation with a physical model scaled at 1:77. The objective was to analyze the flow characteristics of a distinctive type of morning glory spillway (MGS) in the Dokan Dam in Iraq. The study investigated various flow characteristics, including the discharge release, pressure and velocity distributions, and Froude number characteristics. The findings revealed that the relative error of flow rates was generally under 5%, indicating a good agreement between the numerical and physical models. Also, the discharge fluctuation was observed at low water levels and disappeared at higher water levels, due to continuous discharge at elevated water levels. Regarding pressure distribution, most discrepancies between the physical and numerical results were concentrated at specific points within the vertical shaft, and the highest pressure recorded at the bottom of the vertical shaft. Furthermore, the maximum and minimum recorded average velocities were 26.78 and 0.78 m/s, observed at Sects. 3 and 4 for water levels of 516 and 512 m, respectively. Finally, the analysis of Froude numbers showed that the downstream tunnel's flow regime transitioned from subcritical (Fr < 1) for lower water levels (512 and 513 m) to supercritical (Fr > 1) for higher water levels (514, 515, and 516 m) due to increased flow velocities. [ABSTRACT FROM AUTHOR]

This paper analyses the vulnerability of concrete bridges to fire through a comprehensive review and proposes strategies to overcome the fire hazard. As part of mitigation strategies, the application of advanced analysis is illustrated through developing a non-linear transient finite-element model for fire resistance evaluation of prestressed concrete bridge girders. The numerical model is validated using results from fire tests on concrete beams. The model is applied to investigate the effect of girder shape (rectangular and I-shaped sections) and strength of concrete (normal- and high-strength concretes) on the fire resistance of typical concrete bridge girders. Results from the analysis clearly show that fire resistance of high-strength concrete (HSC) girders is lower than that of normal-strength concrete (NSC) girders, which is attributed to its faster degradation of strength and stiffness with temperature. On the other hand, I-shaped girders present lower fire resistance than similar girders of rectangular cross-section due to rapid degradation of its shear capacity. This is mainly the result of slender web widths in I-shaped girders, which results in faster progression of temperatures in the web, leading to early failure under the shear limit state. This problem can be overcome by developing relevant fire mitigation strategies, such as provision of external thermal insulation on girders of critical bridges. [ABSTRACT FROM AUTHOR]

Post-earthquake investigations have shown that piles in liquefiable soils are highly susceptible to damage, especially in sloping sites. This study examines the seismic performance of pile groups with lateral spreading through advanced numerical modeling. A three-dimensional finite element model, validated against large-scale shaking table test results, is implemented to capture the key mechanisms driving the dynamic response of pile groups under both inertial and kinematic loading conditions. Parametric seismic response analyses are conducted to compare the behavior of batter and vertical piles under varying ground motion intensities. The results indicate that batter piles experience increased axial compressive and tensile forces compared to vertical piles, up to 70% and 20%, respectively. However, batter piles provide enhanced lateral stiffness and shear resistance compared to vertical piles, reducing horizontal displacements by up to 20% and tilting the cap by 85% under strong ground motion. The results demonstrate that batter piles not only enhance the overall seismic stability of the structure but also mitigate the risk of liquefaction-induced lateral spreading in the near-field through pile-pinning effects. While vertical piles are more commonly used in practice, the distinct advantages of batter piles for seismic stability highlighted in this study may encourage using more advanced numerical modeling in engineering projects. [ABSTRACT FROM AUTHOR]

Unstable sandy soil poses significant challenges for buried pipelines, particularly due to the increased risk of displacement and stress-induced fractures resulting from soil settlement and earthquake-induced ground deformation. These concerns are especially critical in seismically active regions where underground infrastructure is at higher risk. Fiber-reinforced polymer (FRP) composites present a promising and sustainable alternative for deep foundations, offering durability and reduced maintenance costs compared to conventional materials. This study introduces a novel approach to enhancing the seismic performance of pipelines buried in sandy soils by numerically investigating a three-dimensional (3D) multipipe grouting micro anti-slide pile system, utilizing a polyurethane polymer slurry as the grouting material. Key parameters such as pile spacing, diameter, and length, along with the effects of soil wetting and various earthquake intensities, were examined under the influence of surface loads exerted by a fully loaded truck. The results demonstrate that using polymer micropiles significantly reduces soil and pipeline settlement by 15% to 50%, with larger pile diameters and lengths further decreasing settlement and strain on pipelines. While seismic excitation increases settlement, polymer grouting effectively mitigates this impact, leading to substantial reductions in settlement. [ABSTRACT FROM AUTHOR]

This work presents several results of the stability in steel columns subject to pure compression. A square hollow cross-section with different sizes was considered. This study presents all the analytical equations that need to be used to verify the stability of each column with different lengths and boundary conditions. A finite element program was also chosen to achieve the most critical loads (Euler and buckling resistance loads) in the calculation for each element under study, using linear and nonlinear geometric and material modeling. Steel material was used for the columns, where damage due to plasticity was included, through plastic behavior with isotropic hardening. Comparing the results allows us to conclude that the use of the finite element method is an alternative methodology to be used in other types or configurations of columns, where parameterized tests can be easily implemented and to contribute to the development of a wide-ranging database. The finite element method led to an accurate solution when compared with the analytical results with a maximum deviation of 14.7%. By increasing the column length and reducing the cross-section size, the design buckling resistance of the studied columns also decreases. These studies demonstrate that the length and size of the column cross-section can meaningfully increase the structural behavior of the columns. [ABSTRACT FROM AUTHOR]

Aiming at the problem of mechanical seal failure due to serious wear and tear in operation, the numerical model of the thermal–solid coupling wear of the seal ring is established by taking the friction sub-material as the research object, and the hardness, wear coefficient, and friction coefficient of different soft-ring materials are obtained by a test to verify the accuracy of the numerical model of wear. Additionally, the temperature field and deformation field of the seal ring of different materials are calculated, and the effects of the material parameters, such as elasticity modulus and thermal conductivity, on the temperature, relative deformation, and axial deformation trend are reported. The wear relation of the mechanical seal was optimized, and the correction coefficients of several materials were calculated. The results show the following: the main wear of the seal ring is due to adhesive wear leading to particle shedding and extrusion, adhesive wear causes material transfer, which alters the composition of the worn surface.in turn leading to cratering, which also causes the wear of the seal ring; the friction performance is better when the soft-ring material is graphite (C); the temperature, as well as the deformation, is smaller when the soft-ring material is silicon carbide (SIC); the correction coefficients for the life of SIC are calculated to be 0.23, for C, to be 0.14, and for stainless steel (Ss), to be 0.31, and the corrected equations can more accurately predict the corresponding material. The corrected equation can more accurately predict the service life of the corresponding material. [ABSTRACT FROM AUTHOR]

This research study investigates the impact of various parameters such as L/D ratio, cold mass proportion, inlet pressure, and nozzle count on the performance and thermal energy separation process of a counter flow Ranque-Hilsch vortex tube (VT). Experimental and numerical methods were employed to assess the cold and hot exit temperatures, as well as the thermal energy separation. Four different orifice plates with two, three, five, and six nozzles were used in the experimentation, while air inlet pressure and cold mass fractions were varied between 200–1000 kPa and 0.5–0.7, respectively. The numerical model developed in ANSYS utilized the standard k-ε turbulence model to evaluate velocity and temperature patterns for optimal performance parameters. The results demonstrated that inlet pressure had the greatest influence on VT performance, and higher angular velocity differences were induced between the center and circumferential area of the VT. The study concludes by highlighting the minimum cold exit temperature of − 12 °C and the maximum hot exit temperature of 64.5 °C, as well as providing a useful framework for researchers to assess the thermal energy separation process across different Ranque-Hilsch VTs with varying orifice plates and nozzles. [ABSTRACT FROM AUTHOR]

Here, we describe a dataset of two-dimensional (2D) XBeach model files that were developed for the Coastal Storm Modeling System (CoSMoS) in northern California as an update to an earlier CoSMoS implementation that relied on one-dimensional (1D) modeling methods. We provide details on the data and their application, such that they might be useful to end-users for other coastal studies. Modeling methods and outputs are presented for Humboldt Bay, California, in which we compare output from a nested 1D modeling approach to 2D model results, demonstrating that the 2D method, while more computationally expensive, results in a more cohesive and directly mappable flood hazard result. Dataset:  https://doi.org/10.5066/P9048D1S. Dataset License: CC0 [ABSTRACT FROM AUTHOR]

The study involves numerically simulating the influence of process parameters on melt pool geometry, cooling rate, and microstructure during laser surfacing of 7075 Al alloy using COMSOL Multiphysics. Both numerical simulations and experiments show that increasing scan speeds at a constant laser power reduces melt pool dimensions and increases cooling rates. At 1000 W laser power and 15 mm/s scan speed, numerically simulated melt pool width, depth, and cooling rate are 3.8 mm, 1 mm, and 1370 K/s, closely matching experimental measurements of 4.2 mm, 1.3 mm, and 1449 K/s. Calculated thermal gradient (G) and solidification rate (R) are correlated with observed solidification morphology. The G/R ratio derived from simulations has higher values at the melt pool's bottom, gradually decreasing toward the top for a given laser power and scan speed. This pattern aligns with optical micrographs showing equiaxed dendrites at the top, and columnar and cellular dendrites in the middle and bottom of the melt pool. [ABSTRACT FROM AUTHOR]

The Ba Lang sand beaches, located north of the Nha Trang Bay in Central Vietnam, are famous tourist attractions. However, they are experiencing shoreline and coastal erosion retreat, which is attributed to natural causes (such as tropical depressions, storms, and monsoons) as well as human impacts (such as hydropower generation, sand dredging, and coastal works). According to the forecast of the Vietnam Ministry of Natural Resources and Environment, global climate change will cause the sea level to rise by 74 cm along the coast from the Dai Lanh Cape to the Ke Ga Cape (including the Ba Lang beaches) by the end of this century in the representative concentration pathway (RCP) 8.5 scenario. Sea level rise (SLR) due to global climate change is expected to aggravate the coastal erosion and shoreline retreat problems. In this study, coupled numerical models with the spectral wave module (MIKE 21 SW), hydrodynamic module (MIKE 21 HD), and sand transport module (MIKE 21 ST) in the MIKE 21 package were used to simulate waves, current fields, and sediment dynamics along the Ba Lang beaches considering the impact of SLR. These models were calibrated with the field data measured in December 2016. The results showed that SLR caused the wave height to increase and reduced the current speed and total sediment load in monsoon conditions. The increase in wave height was even intensified under the joint impact of SLR and extreme events.

This paper presents a comprehensive investigation into the impact of geometrical parameters on indoor environments. The study utilizes an experimental setup and a developed numerical model, with validation achieved through comparison with test data from a cabin prototype, focusing on air velocity and temperature profiles. The numerical model undergoes optimization, including turbulence and grid independence analyses, to ensure accurate simulations. Additionally, the study explores the heat source effect on indoor thermal comfort through a series of numerical simulations. Based on the combined numerical and experimental findings, the study establishes robust correlations to explain the variations resulting from these factors. It highlights the crucial roles of roof height and room length in determining aerodynamic characteristics within the room. The study's comparative analysis shows that the Predicted Mean Vote (PMV) remains below 0.45 for a heat flux of 150 W.m-2, indicating a neutral thermal sensation. In contrast, it rises to 2.55 for a heat flux of 800 W.m-2, indicating a warm thermal sensation. Overall, this research provides valuable insights into the complex dynamics of airflow within indoor environments.

In the field of underground mining, the steel props within the coal face are frequently not fully salvaged, resulting in a low recovery rate. At the present time, approximately 60% of coal mining is conducted through underground methods. Consequently, there is a growing number of mechanical roof supports that utilize steel props. Furthermore, as the raw materials for the manufacture of these props are becoming increasingly scarce, it is of paramount importance to recover steel supports from unused mine shafts and those situated along coal seams. However, the recovery process is beset with numerous challenges due to the complex geological conditions and the arduous and perilous nature of the work, which has resulted in a dearth of attention to prop recovery in these areas during the coal mining process. Phase 2 software from Rock science was employed to ascertain the impact of the dismantling equipment on the mining excavation. Therefore, this paper presents a technical solution to enhance the efficiency of the steel prop recovery process in these shafts by utilizing a combination of hydraulic and mechanical structures to form a cohesive equipment setup for effective recovery. [ABSTRACT FROM AUTHOR]

A two-dimensional, sharp-interface two-phase laminar flow numerical model for evaporation from a salt-water falling liquid film with a co-current humid air flow on the interior of a parallel plate vertical channel is presented. The elliptic governing equations in both phases are solved simultaneously in an implicit, fully coupled approach using an in-house Fortran code. The liquid-gas interface is tracked precisely on an automatically adjusted non-orthogonal structured mesh. The basis of the evaporation model is validated for pure water falling film evaporation. A parametric study of evaporation from a salt-water falling film is presented. The study varies the inlet salinity of the film, the inlet liquid Reynolds number, the wall heat flux, and the air relative humidity. The effects of these variations on quantities such as the evaporation rate, the axial velocity, the salinity in the film, and the temperature are presented. The results demonstrate the capablity of the new model to predict the details of falling film thermal desalination. [ABSTRACT FROM AUTHOR]

Abstract The thermal recovery is facing the challenge of improving quality and efficiency. Steam-assisted gravity drainage (SAGD) steam circulation has a profound implications for the formal production. There is a lack of research on the situation when the steam injection pressure of injection well is lower than that of production well during startup stage. In this paper, the effects of diverse injection pressure difference on SAGD steam circulation and production stage are investigated by analytical modeling and numerical simulation, especially when the steam injection pressure of producer well is larger than that of injection well, and reliable results are obtained by temperature falloff test and model comparison validation. Meanwhile, in order to minimize the factors affecting the simulation accuracy, a sensitivity analysis of the temperature prediction model for the startup stage is carried out using Monte Carlo method and the finest possible mesh is used in the numerical simulation. The results show that:①The preheating results are faster and more uniform than the conventional preheating method when steam injection pressure of producer is greater than that of injector, and the subsequent production indexes are also superior to those of the conventional preheating method. ②The injected steam temperature had the greatest effect on the prediction accuracy of the analytical model; The finer the numerical simulation grid division, the lower the midpoint temperature of the horizontal well pair; ③An optimal range of injection pressure differences that achieves the best balance between preheating efficiency and thermal recovery effectiveness is achieved with P prod-P inj in the range of 400–500 kPa. ④The preheating method investigated in this paper minimizes the effect by unfavorable factors such as reservoir non-homogeneity, which holds the potential for more uniform, time-saving preheating and without the addition of field equipment.

Abstract Arsenic contamination in aqueous media is a serious environmental problem, especially in developing countries. In this research, the Box-Behnken response surface methodology was used to optimize the most relevant variables affecting arsenic adsorption on the ZnO-halloysite surface, including temperature, adsorbent dosage, pH, contact time, and As (III) initial concentration. The regression analysis indicated that the experimental data were appropriately fitted to a quadratic model with the adjusted R-squared value (R2) of 0.982 for As(III) adsorption capacity and a linear model with R2 of 0.931 for As(III) removal. The p-values for both adsorption capacity and removal efficiency were below 0.05, with F-values of 116.91 and 115.58, respectively, supporting the model’s validity. The optimum conditions for maximum removal of As(III) were determined through numerical and graphical optimization using the desirability function. It was found that the optimum conditions for adsorption were pH = 7.99, contact time of 3.99 h, As(III) initial concentration of 49.96 mg/L, and adsorbent dosage of 0.135 g/40 ml. The accuracy of the optimization procedure was confirmed by a confirmatory experiment, which showed a maximum arsenic removal of 91.31% and an adsorption capacity of 12.63 mg/g under optimized conditions. Moreover, XPS analysis was performed at different pH levels to investigate the As (III) adsorption mechanism. The results demonstrated that As(III) adsorption occurs at acidic and neutral pH levels. On the other hand, when pH is increased to 8, As (III) oxidizes to As (V), and then adsorption occurs.

Global climate change increases storm frequency and Sea Level Rise (SLR). This leads to an increased risk of coastal flooding, reduced effectiveness of protective structures, and intensified coastal erosion and retreat. The Bona and Ceinturon beaches, two beautiful sandy beaches with low-lying topography along the eastern branch of the Giens double tombolo on the western coast of Hyères Bay, have high tourist value. These areas are very vulnerable to SLR, which is believed to reduce the effectiveness of the shore protection structures built on these sandy beaches. The effects of SLR on changes in the hydrodynamic characteristics of these water bodies need to be quantified. This may help clarify the relationship between SLR and coastal erosion. This study investigated the variation of wave height and current speed due to SLR at the Bona and Ceinturon beaches using a coupled numerical model. The performance of this model was calibrated by comparing the model results with the in situ measured data. The research results are the basis for assessing the impact of SLR due to climate change on this area and provide a useful solution for coastal management in the future.

The existing roofing system in tropical climates is not adapting to the worsening climate, along with the demand for sustainable building design; this study introduced a pioneering cool roof system to reform the traditional roofing system. The pioneering cool roof system is composed of white reflective coating, hollow foamed concrete roof (HFCR) tile, and a sustainable active reflective insulation (RI) system. Despite the complex integrated roof technologies, the study adopted 3D CFD numerical simulation for an in-depth and frontier thermal distribution analysis and fluid flow presentation. The outcomes of the numerical model were compared with field measurements for validation purposes, which resulted in just a 3.31% error. The internal attic was 35.64 °C despite the roof exterior achieving 54.59 °C after receiving an average 680 W/m2 solar radiation source. After the heat flux was hugely terminated by the HFCR tile and sustainable active RI system, the heat flux magnitude attained in the internal attic was 1.0822 W/m2, and the active RI system removed 96.29% of heat flux excellently. Meanwhile, the proposed roofing design's energy-saving performance was 27.5%.

In the present study, a numerical model is developed to predict time-dependent temperature variations inside a solar greenhouse by solving the continuity, Navier-Stokes, and energy Equations using ANSYS Fluent. This paper considers all heat transfer mechanisms into and out of the greenhouse, including convection, radiation, and conduction. The surface-to-surface model and SIMPLE method are employed to analyse thermal radiation between surfaces within the greenhouse and to couple pressure and velocity in solving the flow-field Equations numerically, respectively. This study specifically investigates the unsteady temperature distribution within a solar greenhouse located in Makran, Iran (latitude: 25.3054°N, longitude: 60.6411°E). The numerical method of this study is validated by comparing its results with experimental data. The high accuracy demonstrated by this approach supports the conclusion that the model can effectively study the flow field and thermal behaviour inside solar greenhouses. It is demonstrated that fluctuating boundary conditions cause the thermal conditions inside the greenhouse to vary dynamically over time. The results depict the spatial variation of temperature distribution at different levels from the soil surface at 13:00 on the first and second days of modelling in Makran. These insights are expected to play a crucial role in improving greenhouse design and management practices in agriculture.

Abstract Jakarta is the center of Indonesia’s economy and development. However, the city of Jakarta suffers from many problems related to groundwater, and good groundwater governance is needed to realize groundwater sustainability. Groundwater management can be initiated by undertaking conceptual and numerical groundwater modeling. This paper reviews several previous studies related to groundwater modeling of the Jakarta groundwater basin that have provided information about the groundwater system and groundwater quantity. However, improvements are required for any further studies. The critical challenges to providing a complete picture of the groundwater conditions in the Jakarta groundwater basin are the availability of reliable data and improved groundwater flow models.

Abstract Although many desalination plants have been built in the countries around the Persian Gulf (PG) over the past decade, there exist crucial water demands in this region. Considering the limited water exchange between PG and the open seas, effluents more than the natural capacity of the PG will increase the sea-water salinity continuously. This excess salinity, in addition to threatening the marine ecosystems, endangers the water supply for many population centers. This study provides a comprehensive numerical analysis of the impact of existing and new desalination plants on the PG’s salinity. In addition, the water residence time and pollutant extension have been investigated in the PG. There exist several concerns, especially in recent years about the probable threat of desalination growth in semi-enclosed seas such as PG. The effect of desalination plants on the mean salinity of PG is one the questions investigated in this research. Results demonstrate that the water residence times in the southern and northwestern regions are more than five years. This time is reduced to nearly 26 to 45 months in the eastern regions near the Strait of Hormuz. Generally, the desalination plants have a negligible effect on the salinity of PG in comparison with the climate conditions such as evaporation and water exchanges. Based on the results, a 50% increase in effluent discharge of existing desalination plants increases the average salinity of the PG by only 0.01 psu. However, the annual volume of net evaporation (that exits the clean water directly) is nearly 36 times more than the effluent discharge from the existing desalination plants. Furthermore, this value is almost 0.2% of the amount of water that enters the PG through the Strait of Hormuz. In spite of these findings, the regional effects can be significant in some parts of the PG. For example, the southern and western coasts of PG are generally more vulnerable to pollution than other areas. The main reason is the shallow water depth in these areas and the water recirculation pattern. Some sensitive local areas have been also addressed in this study. Among the studied regions, the coastlines at the northwest of PG and at the north the Qeshm Island are two susceptible areas. The findings of this study underscore the importance of considering a new integrated viewpoint in developing desalination plants within PG.

Nowadays a major energy transition aimed at cutting CO2 emissions has begun, with the ambitious goal of drastically reducing the dependence on fossil fuels and promoting the use of renewable energy sources. In this context, energy storage systems play a key role in ensuring a stable, secure and time-aligned energy availability. Open sorption thermal energy storages (TESs) can contribute to such transition, since they are simple and cheap devices able to provide a hot airflow with a high energy density and to store energy for long time. In this work, open sorption TES systems operated with Zeolite13X are investigated with a focus on the integration in practical applications. First, the experimental analysis and modelling of the sole TES system is described. Then, the integration of the TES at system level is carried out. The analysis evidences that a significant reduction of storage capacity occurs if air humidification is necessary before the adsorption process or afterwards to keep adequate indoor comfort conditions for the occupants. For the exemplary case study considered, an energy density of 150 kWhm−3 can drop to 40 kWhm−3 in case of complete compensation of the adsorbed water through a humidifier. This paper provides useful guidelines for evaluating the performance of a TES integrated system in terms of specific energy and efficiency. It also identifies applications involving high latent loads (e.g., swimming pools, locker rooms) or for which low relative air humidity is required (e.g. interior of vehicles to prevent condensation on windows) as particularly beneficial for using a TES system.

Abstract Coal‐measure strata is a typical layered structure, a better understanding of the bearing characteristics of fully grouted bolts in layered rock mass is of great significance for roadway support. However, limited studies have been conducted to investigate the bearing performance of fully grouted bolts in layered rock mass. In this paper, a numerical model of fully grouted bolt in layered rock mass was established, and a tri‐linear bond–slip model of the anchorage interface was imported into the numerical model by the user‐defined Fish language. The effects of strata sequence, strata thickness, and strata number in layered rock mass on the bearing performance of fully grouted bolts were systematically analyzed. The results show that fully grouted bolts in soft–hard type (SH‐type) layered rock mass has higher bearing capacity. The greater the thickness of the soft rock in the layered rock mass, the more significant the influence of the strata sequence on the bearing performance of fully grouted bolts. The bearing capacity of fully grouted bolts decreases with the increase of the thickness ratio of soft rock to hard rock. The greater the thickness of the hard rock in the layered rock mass, the more beneficial to the bearing performance of fully grouted bolts. With the increase of the strata number, the bearing capacity of fully grouted bolts gradually decreases. For bolt support of layered rock mass, the deep anchoring foundation of fully grouted bolts should be arranged in hard rock or elastic zone rock as much as possible, and rock grouting can be adopted to reduce the difference in mechanical properties between layered rock mass and improve the durability of fully grouted bolts. The research results may provide useful guidance and reference for the support design of fully grouted bolts.

Arsenic contamination in aqueous media is a serious environmental problem, especially in developing countries. In this research, the Box-Behnken response surface methodology was used to optimize the most relevant variables affecting arsenic adsorption on the ZnO-halloysite surface, including temperature, adsorbent dosage, pH, contact time, and As (III) initial concentration. The regression analysis indicated that the experimental data were appropriately fitted to a quadratic model with the adjusted R-squared value (R2) of 0.982 for As(III) adsorption capacity and a linear model with R2 of 0.931 for As(III) removal. The p-values for both adsorption capacity and removal efficiency were below 0.05, with F-values of 116.91 and 115.58, respectively, supporting the model's validity. The optimum conditions for maximum removal of As(III) were determined through numerical and graphical optimization using the desirability function. It was found that the optimum conditions for adsorption were pH = 7.99, contact time of 3.99 h, As(III) initial concentration of 49.96 mg/L, and adsorbent dosage of 0.135 g/40 ml. The accuracy of the optimization procedure was confirmed by a confirmatory experiment, which showed a maximum arsenic removal of 91.31% and an adsorption capacity of 12.63 mg/g under optimized conditions. Moreover, XPS analysis was performed at different pH levels to investigate the As (III) adsorption mechanism. The results demonstrated that As(III) adsorption occurs at acidic and neutral pH levels. On the other hand, when pH is increased to 8, As (III) oxidizes to As (V), and then adsorption occurs. [ABSTRACT FROM AUTHOR]

Residual stresses with a complex distribution are generated after linear friction welding, which affects the service performance of the weldment. In this work, a numerical model for linear-friction-welded Ti17 (Ti-5Al-2Sn-2Zr-4Mo-4Cr) was developed to investigate the evolution of residual stresses and the effect of welding parameters on residual stresses. Additionally, a method for predicting internal residual stresses was constructed. The results indicate that the residual stresses near the contact interface are largest in the oscillatory direction, peaking at ~661 MPa at 2 mm away from the contact interface. The evolution of stresses is not only related to the inhomogeneous thermal gradient, but also to the forging force. And the stress distribution essentially stabilizes within the duration of the forging force applied. Increasing the amplitude and frequency results in higher peaks of tensile residual stresses and a more concentrated distribution. Conversely, increasing the forging force only reduces the magnitude of the residual stresses. The developed prediction method, based on the similarity of internal residual stress distributions, facilitates the prediction of internal residual stresses using measured surface residual stresses. [ABSTRACT FROM AUTHOR]