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Influence of overlay strength degradation on bond stresses of bridge deck system

This research paper intends to numerically investigate the impact of selected factors on the strength of the concrete overlay-bridge deck bond, directly and indirectly, using the nonlinear finite element analysis (NLFEA) method. Besides, the research introduces the guidelines necessary to attain adequate bond strength to eliminate the possibility of concrete detachment under the effect of different developed stresses. The NLFEA has been utilized in predicting and correlating the live applied loads and the induced shrinkage stresses at the interfacial region between the concrete overlay and the bridge deck. The developed stresses were related to the overlay's direct tensile bond strength. A total of 336 NLFEA models of overlay-bridge deck slab segments were designed and examined after being properly validated. The parameters of the study were as follows: the overlay degradation level (0 %, 19 %, 36 %, 51 %, 64 %, and 75 %); the ratio of the overlay's relative thickness-to-the bridge deck slab (toverlay/tslab); in addition to the age of the shrinkage induced stresses (early age (3 and 7 days) and moderate age (14 and 28 days)). The NLFEA live load and shrinkage stress values were validated using experimental results from the literature with difference percentages of less than 5 %. The numerical study results recommended that the thickness of the concrete's overlay should be within certain overlay thickness limits to be capable of handling the lower and higher stresses at the service and overloading conditions. The proposed guidelines enable the avoidance of unfavorable detachment between the interface parts under the effect of AASHTO HS-20 truck cyclic and impact loadings, as well as shrinkage loading.

Influence of repeated surface surcharge loading on tunnel displacement considering the structural characteristics of soft clay

Shanghai soft clay is a typical marine clay with specific structural characteristics. However, the effects of surface surcharge loading on structured soft clay and existing tunnels remain unclear. In this study, the effect of repeated surface surcharge loading on tunnel displacement was numerically investigated, considering the structural characteristics of Shanghai Layer 4 soft clay. An elastoplastic constitutive model (Shanghai model) that describes the mechanical properties and structural characteristics of natural clay was used to simulate the soil response. The results indicate that the first cycle of repeated surface surcharge loading had the greatest effect on the displacement of the tunnel and overlying clay; subsequent loading cycles further increased the displacement. With repeated surface surcharge loading, the displacement of the overlying clay exhibited a significant decreasing trend with increasing depth. The maximum excess pore pressure of the clay exhibited a decreasing trend with increasing loading time. The displacements of the tunnel and overlying clay were greater when the effects of the soil structure were considered. However, the initial degree of the structure had no significant effect on the accumulation of excess pore pressure when the surface surcharge loading did not reach the ultimate bearing capacity of the clay.

A Virtual Resistance Optimization Method Based on Hybrid Index in Low-voltage Microgrid

Introduction: The introduction of virtual resistance can effectively suppress the circulating current between micro-sources and improve power allocation in low-voltage microgrid, but it also causes the voltage deviation of micro-sources’ inverters. An optimization method of virtual resistance based on hybrid index is proposed in order to suppress circulating current and improve voltage deviation at the same time in this paper. The gradient descent method is used to design the virtual resistance optimization process, aiming at the optimization of hybrid index composed of circulating current and voltage deviation. The constraints are deduced with power quality requirements, capacity limitation and static stability, and then virtual resistance values are optimized. The effects of switching load and micro-source on the optimization results are analyzed through the simulation of low-voltage microgrid, and the simulation results show that the virtual resistance optimization method can significantly suppress circulating current while improving power quality. When distributed generators are connected to utility grid through inverters and feeders, differences in feeder parameters and inverter control strategies easily cause circulating current and uneven power distribution among micro-sources. The introduction of virtual resistance can effectively suppress the circulating current between micro-sources and improve power allocation in low-voltage microgrids, but it also causes the voltage deviation of micro-sources’ inverters. An optimization method of virtual resistance based on hybrid index is proposed in order to suppress circulating current and improve voltage deviation. Methods: The gradient descent method is used to design the virtual resistance optimization process, aiming at the optimization of hybrid index composed of circulating current and voltage deviation. The constraints are deduced with power quality requirements, capacity limitation and static stability, and then virtual resistance values are optimized. Results: In the simulation scenario of two micro-sources and three micro-sources, the virtual resistance obtained by the method proposed in this paper has more obvious improvement on the system operation index, and is not affected by the load type. Conclusion: The method of optimizing virtual resistance based on the hybrid index can achieve the effect of restraining circulating current and improving power sharing degree on the premise of guaranteeing power quality and satisfying system stability. The optimization of virtual resistance is affected by the number of feeders. It is necessary to re-optimize the virtual resistance after changing the number of feeders, but the process of switching micro-source and adjusting load does not affect the optimized resistance value.

Tunnel rockbursts induced by dynamic disturbances: mechanism and mitigation

Rockbursts are characterized by violent rock fractures and pose a significant threat to hard-rock tunnels, potentially resulting in casualties and damage to excavation spaces. Globally recognized as one of the least understood and most feared challenges in underground excavations, rockbursts are often triggered by dynamic disturbances such as engineering activities or nearby vibrations. This study conceptualizes rockbursts as dynamic buckling or instability issues inherent in rock structures. It specifically investigates the mechanism of tunnel rockbursts induced by ambient blasting. The derivation of the governing equation of motion, which incorporates shear deformation and rotary inertia of the rock column, results in coupled Mathieu equations. By employing the proposed numerical method, the conditions triggering rockburst were established using instability diagrams. The study examines the effects of static components, dynamic loading, and frequency on a tunnel example, revealing that the amplitude and frequency of dynamic disturbances are critical in influencing the occurrence of tunnel rockbursts through perturbation effects and parametric resonance mechanisms. These insights offer valuable understanding into the mechanisms, mitigation, and control of tunnel rockbursts.

Multiple heating loads participate in the system power regulation control strategy

With the addition of a high proportion of new energy and power electronic equipment, the power system has shown characteristics such as low inertia and significant energy output fluctuation, which has brought great challenges to power/frequency regulation and control of the power system. Therefore, this article uses the inertia characteristics of heat energy on the load side and exerts reasonable start-stop control to play a positive and beneficial role in the power regulation of the power system. Firstly, the room temperature variation process was transformed into a lumped parameter equivalent model. A lumped parameter heat transfer model of a single typical load was built in Simulink, and its dynamic characteristics were analyzed by symbolic calculation. Based on this, a time-domain simulation was carried out to explore the influence of the law of system parameters and external input on the change of system state quantity. Based on time domain simulation, the behavior of the heating load is analyzed. Then, the effects of typical and multiple loads on system power regulation at different outdoor temperatures are studied. It is found that when the average outdoor temperature decreases, the sustainable time of system power upturn will increase, and the sustainable time of downturn will decrease. The power curve of multiple loads simultaneously is more stable, and the adjustment ability is stronger. The reasonable and flexible control method of load switch setting, namely the coherent characteristic load power regulation strategy, realizes the sustainable power optimization of the load to the system in the specified period.

Hyperglycemia and Central Obesity Disrupt Conditioned Pain Modulation: A Single-Blind Crossover Randomized Controlled Trial

Hyperglycemia and high adiposity are risk factors for pain in diabetes. To clarify these links with pain, the effects of a glucose load on sensory detection, pain sensitivity, conditioned pain modulation (primary aims), and autonomic and endothelial functions (secondary aims) were examined in 64 pain-free participants: 22 with normal adiposity (determined by dual-energy X-ray absorptiometry), 29 with high adiposity, and 13 with combined high adiposity and elevated glycated hemoglobin (HbA1c; including prediabetes and type 2 diabetes). Participants ingested either 37.5 g glucose or 200 mg sucralose (taste-matched) in the first session and crossed over to the other substance in the second session 1 month later. At baseline, painful temple cooling (the conditioning stimulus) inhibited pressure- and heat-pain in the ipsilateral arm (the test stimuli) immediately after cooling ceased (partial η2’s > .32). Glucose ingestion weakened pressure-pain inhibition irrespective of HbA1c levels (partial η2 = .11). However, a larger reduction in pressure-pain inhibition after ingesting glucose was associated with a higher waist/hip ratio (r = .31), suggesting a role of central obesity. Heat-pain inhibition was absent at baseline in unmedicated participants with elevated HbA1c, and these participants reported more occlusion-induced pain after ingesting glucose (partial η2’s > .17). Glucose ingestion interfered with parasympathetic activity in all participants (partial η2 = .11) but did not affect endothelial function (measured by reactive hyperemia) or alter other sensations (eg, feet vibration detection). The disruptive effect of hyperglycemia on conditioned pain modulation increases in line with central obesity, which might facilitate pain in diabetes. PerspectiveIngesting 37.5 g glucose (approximately 350 mL soft drink) interfered with pain modulation in pain-free adults with normal adiposity or with combined high adiposity and HbA1c levels. The interference was stronger alongside increasing central obesity, suggesting that controlling blood glucose and body fat mass might help preserve pain modulation.

Prediction of Airport Taxiway Settlement based on CNNBiLSTM-Attention

The accurate real-time prediction of complex time series in airport runway settlement is crucial. In order to achieve precise and reliable predictions of runway surface settlement, considering the nonlinear and time-dependent characteristics of settlement data under the coupling effects of dynamic loads, water levels, and other factors, a CNN-BiLSTM-Attention approach is proposed. This method first employs Convolutional Neural Networks (CNN) to extensively extract local temporal features from the input sequences. Subsequently, the extracted local temporal features are input to BiLSTM layers to learn the features of the sequences both in the forward and reverse directions. Finally, the output of the BiLSTM layers is fed into an attention mechanism layer. By computing attention weights, crucial information in the input sequences is weighted and added to enhance the model’s focus on key information. The final settlement prediction is then generated through a fully connected layer. To validate the proposed method, field settlement monitoring data from Runway L at Hangzhou Xiaoshan Airport are utilized as an engineering case study. The results indicate that the combined model captures local features of settlement sequences more effectively with a smaller dataset, achieving higher accuracy compared to a standalone BiLSTM model.

The SPES Laser Ion Source: Time Structure and Laser Enhancement Measurements with Sm+ beam

A two-step resonance photo-ionization scheme has been used to ionize samarium atoms in the SPES tantalum hot-cavity ion source. The effect of the ion load on the ion beam time structure and the laser enhancement of the ion yield has been studied at different ion source temperatures. Generally, the introduction of more positive ions (ion load) affects negatively the overall confinement of the laser ions inside the volume of the ion source. Possible enhancement of the laser ion confinement through the introduction of neutrals is observed as well. The ion load is also observed to affect the confinement in the transfer line much more than in the hot cavity. Measurement of the time structure with inverted polarity of the cavity DC heating supply confirmed the significance of the longitudinal potential for ion extraction. The laser enhancements of the ion yield are found to be sensitive to the ion load at low operating temperature of the ion source i.e. 1800°C, whereas at 2050°C and 2200°C, they are relatively stable till an ion load value of 1.2 µA.

Influence of loading on the heat transfer rate and specific water consumption of detached loosed fresh palm fruits during vertical mini-batch sterilization

This study presents the effect of loading on the heat transfer rate and specific water consumption of detached loosed fresh palm fruits during sterilization. Sterilization is an integral process of palm oil extraction that consumes a lot of water. However, most industrial research in the past focused on fresh fruit bunch (FFB) sterilization dynamics. At the same time, the medium- and small-scale industries sterilize already detached loosed fresh palm fruits (LFPF) that have been removed from the spikelet as purchased from aggregators. Therefore, the process data generated from the sterilization of FFB might not be optimal for sterilizing LFPF. This study, therefore, investigates the transient response of variation in LFPF loading of the sterilization chamber to steam injection during steam sterilization of LFPF at 3 ± 0.5 bars using a vertical, single-peak LFPF sterilizer that combines the boiler and sterilizer in a single unit. The LFPF were loaded at mass intervals of 0.2 kg ranging from 0.2 kg to 2 kg. The vapour temperature dynamics, heat transfer rate, steam energy utilization efficiency and specific water consumption parameters were studied. The average vapour temperature varied from 100 °C to 130 °C for the LFPF mass range of 0.2 to 2 kg at steam injection temperature of 140 °C and pressure of 3 ± 0.5 bars. This temperature range matched the saturated vapour temperature of pure water at 1.0––2.8 bars absolute pressure but slightly lower than the saturated vapour temperature of 133.54 °C for pure steam at 3 bars. The percentage of steam energy utilization effectiveness is inversely related to the steam mass flow rate. While energy effectiveness increased with loading mass, the steam mass flow rate decreased with increased LFPF mass. The value of the heat transfer rate ranged between 1.7––55.4 W, while the specific heat transfer rate ranged between 8.5–––41.8 W/kg. The average specific water consumption ranged from 0.014 to 0.09 kg-water/kg-LFPF, with an average value of 0.031 kg-water/kg-LFPF. This value is lower than 0.112–––0.5 kg-water/kg-FFB, with an average value of 0.256 kg-water/kg-FFB for conventional FFB steam sterilization. This represents an 87.9 % reduction in water consumption in conventional FFB steam sterilization. An empirical model deduced for specific heat transfer rate and water consumption for steam sterilization of LFPF at 3 ± 0.5 bars and vapour temperature range of 100––130 °C showed a high coefficient of determination above 99 %.

Design and Biomechanical Analysis of Customized Angled Abutment Based on Tooth Inclination Angle for Immediate Implant Placement on Maxillary Anterior Region.

Finite element analysis and an in vitro experiment were employed to investigate the loading effects of angled abutments, comparing various customized angled abutments derived from the average angle of incisors in patients with a commercial 15°∆ angled abutment, on both the implant and surrounding bone. Four customized angled abutment models (21.9°∆, 24.15°∆, 20.22°∆, 33°∆) were developed using cone-beam computed tomography (CBCT) images of incisor inclination from various age groups of patients. 3D maxillary bone models were created from CBCT images of four individual patients. Finite element analysis and in-vitro strain gauge experiments were conducted, applying 100N or 50N of axial or oblique force, to assess the differences in stress/strain between the customized and the commercial 15°∆ angled abutments in both the implants and surrounding bone. Under axial loading, the stress values in the dental implant and surrounding bone were elevated due to the relatively higher angles of the customized angled abutments (21.9°∆, 24.15°∆, 20.22°∆, 33°∆) when compared to the commercial 15°∆ angled abutment; however, under oblique loading the commercial 15°∆angled abutment exhibited higher stress values in both the implant and surrounding bone. For in vitro experiment, there is no statically difference in bone strain between the customized (21.9°∆) and the commercial 15°∆ angled abutments in axial loading. Nevertheless, in oblique loading using a commercial 15°∆ angled abutment induced the higher bone strains. Customized angled abutments offer lower stress/strain under oblique loads but higher stress/strain under axial loads compared to commercial ones. Therefore, in the design and application of angled abutments, careful consideration of the occlusal load direction is paramount for achieving biomechanical success of dental implant.

The behavior of reinforced concrete frames exposed to high temperature under cyclic load effect

Continued use of the structure through minor renovations and repairs without a complete and accurate determination of the extent of damage to the structure and its elements exposed to high temperature effects due to fire, etc. will cause more loss of life and property in the event of an earthquake that may occur later. The aim of this study is to determine the losses on the lateral load and energy damping capacities and stiffness of reinforced concrete frames exposed to 200, 400, 600 and 800 ℃ high temperatures for 60, 120 and 180 min. For this purpose, 13 reinforced concrete frame test elements with the same concrete and steel material properties and dimensions were produced. All reinforced concrete frame test members were brought to the specified target temperature within one hour and exposed to high temperature effects for 60, 120 and 180 min at these target temperatures. The test members then allowed cooling down on their own and when they reached room temperature, they removed from the oven and subjected to cyclic lateral loading tests. The data obtained from the cyclic lateral loading tests processed to obtain lateral load - horizontal displacement, stiffness - horizontal displacement, cumulative energy consumption - horizontal displacement and strength envelope curves for each test element. According to the results of the cyclic lateral loading tests, it was determined that the lateral load carrying capacities of the test members exposed to high temperature for 60, 120 and 180 min decreased by 24 %, 33.33 % and 36 % in push, and by 25.76 %, 37.6 % and 38.72 % in pull, respectively. In addition, the energy consumption of the test elements exposed to high temperature for 60, 120 and 180 min decreased by 30.98 %, 42.41 % and 39.62 %, respectively, compared to the reference test element. The initial stiffness of all test elements exposed to the high temperature effect decreased compared to the initial stiffness of the reference test element not exposed to the high temperature effect. According to these results, the effect of high temperature causes losses in many parameters that are of vital importance in the building elements, but also highly affects the earthquake behavior of the building.

Research on the Support Performance of Internal Feedback Hydrostatic Thrust and Journal Bearing Considering Load Effect

This study aims to analyze the impact of uniform and eccentric load conditions on the performance of internal feedback hydrostatic thrust and journal bearing. Two distinct models are established: a three-degrees-of-freedom uniform load model and a five-degrees-of-freedom eccentric load model. The support stiffness, overturning stiffness, and flow rate for both thrust and journal bearings are calculated. Additionally, numerical analysis is conducted to examine the influence of oil film thickness, inlet pressure, and restrictor size on the operational characteristics of the bearings, revealing the interplay between an eccentric load and journal bearing speed. The validity of the theoretical algorithm is verified through finite element simulation. The research outcomes hold significant guiding implications for the design and application of internal feedback hydrostatic bearings.

Study Performance of Floating Columns Subjected to Vertical Loads

In many cases, we need large areas in the building that are free of columns, especially on the lower floors, such as the ground floor and the basement, in order to use them as car parking or otherwise. The load path will change and new terms will appear, including the term ”floating column”, which is the column above the removed column, and the term Transfer beam, is the beam that the floating column is based on it as a concentrated load and then transfers the loads to the adjacent columns. In this paper, the effect of vertical load on a concrete building containing a floating column has been studied and compared to another one without a floating column. Also, the results of the Transfer beam were compared in a number of parameters such as moment, shear force, and deflection. A building consisting of G+4 was studied and analyzed using ETABS, SAFE, and Midas programs, A number of results were reached, the most important is the concept of load path redistribution, also this paper concluded that in normal buildings case all beams have an approximately equal result of bending, shear, and deflection but in floating column building the beams above the Transfer beam have different values which decrease when going upward.

Foundation Types of Fixed Offshore Wind Turbine

Offshore wind turbines are supported by various foundations, each with its considerations in design and construction. Gravity, monopile, and suction bucket foundations encounter geotechnical issues, while jacket and tripod foundations face fatigue problems. Considering this, a gravity foundation based on a steel skirt was developed, and a monopile foundation was analyzed for Pile-Soil Interaction using the p–y curve and 3D finite element method (3D FEM). In addition, for suction bucket foundations, the effects of lateral and vertical loads were analyzed using 3D FEM and centrifuge tests. Fatigue analysis for jacket and tripod foundations was conducted using a hotspot stress approach. Some hybrid foundations and shape optimization techniques that change the shape to complement the problems of each foundation described above were assessed. Hybrid foundations could increase lateral resistance compared to existing foundations because of the combined appendages, and optimization techniques could reduce costs by maximizing the efficiency of the structure or by reducing costs and weight. This paper presents the characteristics and research directions of the foundation through various studies on the foundation. In addition, the optimal design method is presented by explaining the problems of the foundation and suggesting ways to supplement them.

Centrifuge modelling of end-bearing slender energy pile performance under temperature cycles

Slender energy pile shows a buckling deformation behavior under the coupling effect of temperature cycles and external loads, significantly affecting the long-term serviceability and even leading to the buckling failure. To investigate the thermo-mechanical performance of end-bearing slender energy piles under the long-term effect of temperature cycles, a centrifuge modelling experiment was conducted in this work, in which the temperature distribution, displacement, axial force and bending moment of the energy pile during the long-term temperature cycle were measured. The results unveiled that the axial force of the end-bearing slender pile increases as temperature rises, potentially leading to a displacement neutral point in the lower part of the pile. Meanwhile, there was an embedding effect in the lower part of the slender pile, with a preliminary calculated embedment depth of 36.2 meters. Temperature fluctuations can soften the soil at the pile end over time, diminishing the embedding effect on slender piles, and causing a reverse bending point to emerge at a depth of 45.5 meters. The appearance of bending moments in the pile signaled the horizontal displacement encountered in the pile service life, warning the bearing capacity loss problem from changes in pile deflection.

Revealing the Effect of Typhoons on the Stability of Residual Soil Slope by Wind Tunnel Test

Typhoon-induced slope failure is one of the most important geological hazards in coastal areas. However, the specific influence of typhoons on the stability of residual soil slopes still remains an open issue. In this study, the Feiyunjiang catchment in Zhejiang Province of SE China was chosen as the study area, and a downscaling physical model of residual soil slopes in the region was used to carry out the wind tunnel test. Our aim was to answer the question, How does the vegetation on the slope and slope stability respond during a typhoon event? For this purpose, multiple aspects were monitored and observed under four different wind speeds (8.3 m/s, 10.3 m/s, 13.3 m/s, and 17 m/s), including vegetation damage on the slope, macrocracks on the slope surface, wind pressure, wind load, permeability coefficient of the soil layer, and slope stability. The results showed that the plants on the slope could restore to their original states when the wind speeds ranged from 8.3 m/s to 13.3 m/s, but were damaged to the point of toppling when the wind speed increased to 17 m/s. Meanwhile, evident cracks were observed on the ground under this condition, which caused a sharp increase in the soil permeability coefficient, from 1.06 × 10−5 m/s to 6.06 × 10−4 m/s. The monitored wind pressures were larger at the canopy than that at the trunk for most of the trees, and generally larger at the crown of the slope compared with the toe of the slope. Regarding the wind load to the slope ground, the total value increased significantly, from 35.4 N under a wind speed of 8.3 m/s to 166.5 N under a wind speed of 17 m/s. However, the wind load presented different vector directions at different sections of the slope. The quantitative assessment of slope stability considering the wind load effect revealed that the safety factor decreased by 0.123 and 0.1 under the natural state and saturated state, respectively, from no wind to a 17 m/s strong wind. Overall, the present results explained the mechanism of slope failure during typhoon events, which provided theoretical reference for revealing the characteristics of residual soil slope stability under typhoon conditions.

Graphene/graphene oxide and melamine as synergistic additives for polyester nanocomposite coatings

Ensuring mechanical robustness is crucial for polyester coatings on pre-coated metal (PCM). The incorporation of nanofillers such as graphene nanoplatelets (GNP) and graphene oxide (GO) has demonstrated potential in enhancing mechanical properties of polymeric nanocomposites. However, the utilisation of these nanofillers in saturated polyester systems remains largely unexplored. Therefore, this study developed polyester-based nanocomposite coatings incorporating GNP or GO and systematically investigated the effects of the nanofiller loading and the hexa (methoxymethyl)melamine (HMMM)/polyester ratio on the properties of the coatings. Adding nanofillers led to the reduction of both glass transition temperature (Tg) and hardness (H) of the coating. Specifically, at a 1:5 HMMM/polyester ratio, Tg reduced from 29.9 °C for plain polyester (Blank) to 26.1 °C and 22.0 °C for polyesters with 5 wt% GNP (A-5.0GNP) and GO (A-5.0GO) respectively; H values also decreased from 274 MPa for Blank polyester to 222 MPa and 143 MPa for A-5.0GNP and A-5.0GO, respectively. The hydroxyl groups on the nanofillers affected crosslinking between HMMM and polyester by reacting with HMMM, thereby reducing the crosslink density of the cured coatings. Increasing nanofiller loading led to a more significant reduction in crosslink density, resulting in decreased Tg and H values. At the same loading level, the significantly higher hydroxyl content of GO had a more pronounced effect in reducing crosslink density compared to GNP. Furthermore, an increase in HMMM compensated for the HMMM loss to GO and facilitated the polyester crosslinking reactions, leading to significant increase in both Tg and H. Specifically, for the 2 wt% GO nanocomposites, Tg increased significantly from 24.7 °C to 32.1 °C with a rise in the HMMM/polyester ratio from 1:5 to 1:2, while the H value increased notably from 193 MPa to 452 MPa.

Effect of axial preloads on torsional behavior of superelastic shape memory alloy tubes – experimental investigation and simulation/predictions of intricate inner loops

Shape memory alloy (SMA) devices (utilizing wires/rods, springs or tubes) engage unique superelastic/pseudoelastic (SE) phenomenon for large stroke recovery, energy dissipation and damping applications. In particular, SMA components in torsion are also generally subjected to some pre-tension loads and hence understanding their combined effects on the torsional response is vital. In this work, some intricate internal loop and outer loop responses (large twists > 1500°) of SMA tubes under different twisting-untwisting scenarios are investigated to understand the effects of static pre-load on torsional responses. Key SMA hysteretic features like sink point memory (SPM) and return point memory (RPM) have not been well understood under torsion (with and without axial loads) have been investigated here. Further, a modified two variant thermodynamic Preisach modeling approach is proposed to simulate responses of twisted tubes with varying extents of twist and different axial loads. The central principle here is the use of a Gibbs Potential framework to separate the dissipative and thermoelastic parts of the SE responses using well established thermodynamic principles and then utilizing a non-ideal switching type disjunctive Preisach model to fit the nonlinear hysteretic dissipative section of the SE response. By using the outer loop response for model calibration, other complex loading unloading scenarios leading to intricate internal loops and effects of axial loads on these can be predicted. It is also shown that addition of a single interior loop detail for model calibration significantly enhances prediction of other more intricate internal loops. This approach dramatically simplifies the experimental data needed for the simulation of SMA components even under complex loading.

Analyzing the Seasonal Vertical Displacement Fluctuations Using the Global Navigation Satellite System and Hydrological Load: A Case Study of the Western Yunnan Region

The non-tectonic deformation caused by hydrological loads is an important influencing factor in GNSS vertical displacement. Limited by the temporal and spatial resolution of global models and model errors, the hydrological load results calculated by traditional methods are difficult to meet the high temporal and spatial resolution requirements of small to medium-scale regions. This paper introduces the idea of the remove–restore method, assimilates regional high-resolution hydrological data, and obtains higher temporal and spatial-resolution hydrological load results. Subsequently, utilizing data from 12 CORS observed in the western Yunnan region between January 2018 and December 2020, the quantitative relationship and variation characteristics between GNSS vertical displacement and hydrological load displacement were analyzed in detail. Furthermore, the annual signals of both were extracted using the SSA method for comparative analysis. After removing the effects of atmospheric load and non-tidal ocean load, the average correlation coefficient between GNSS vertical displacement and hydrological load displacement is 0.84, with an average reduction of WRMS (%) reaching 37.17%. The average correlation coefficient of the annual signals between GNSS vertical displacement and hydrological load deformation is 0.94, with an average reduction of WRMS (%) reaching 46.5%, indicating that the contribution of hydrological load to the GNSS non-tectonic vertical displacement annual signal is close to 50%. The research results provide scientific support and important references for studying surface tectonic deformation by removing non-tectonic deformations such as hydrological loads from GNSS vertical displacement. Additionally, it helps to explore the mechanisms of interaction between water storage migration and surface deformation.

Biodegradable maleic–itaconic polymer‐coated phosphatic fertilizer improved phosphorous recovery in calcareous soil

AbstractBackgroundThe poor nutrient recovery of phosphatic (P) fertilizers in calcareous soils is a serious worldwide problem resulting in sub‐optimal P use efficiency. This is mainly attributed to P fixation with calcium (Ca) and magnesium (Mg) ions in the soil solution. As a result, most of the applied P (in the form of fertilizer) becomes insoluble or immobilized in soil due to complex edaphic processes, making it unavailable to plants. Polymer‐coated fertilizers are relatively new approaches to minimizing P‐fixation. However, concerns have been recently raised on the environmental effects of synthetic polymers and microplastic loads in agroecosystems.AimHere we developed and investigated the effectiveness of biodegradable polymer‐coating on commercial diammonium phosphate (DAP) fertilizer to improve P availability in the soil, hence making P more accessible for plant uptake.MethodsThe polymers were coated on DAP fertilizer granules, and two products based on increasing polymer concentration (namely, C‐1 and C‐2, respectively) were achieved. The coated and uncoated DAP granules were characterized for surface properties to confirm the appropriate coating of polymers using scanning electron microscopy (SEM) and crushing strength by a universal telson machine. The biodegradable polymer‐coated C‐1 and C‐2 fertilizers were tested for P availability compared to commercial DAP using spinach as a test plant.ResultsThe SEM micrographs indicated a uniform coating of biodegradable polymers on DAP granules. Application of C‐1 increased the plant's fresh and dry biomass (+10.71% and +18.09%) over commercial DAP, respectively. The C‐1 application increased the N, P, and K uptake by +24.9%, +66.7%, and +11% over commercial DAP. In contrast, C‐2 produced less biomass than C‐1 due to relatively less nutrient uptake and different concentrations of ingredients in C‐2.ConclusionTogether, our results showed that the novel biodegradable polymer approach has demonstrated the potential to improve P recovery and agronomic yield in alkaline soils.