Side Surface Research Articles

Interlocking passive brick set: the design of interlocking building components with connecting air cavities for heat dissipation and as a complement to the Heating, Ventilation, and Air Conditioning (HVAC) system

This dissertation explores the design and implementation of the "Interlocking Passive Brick Set," a building component aimed at enhancing thermal efficiency and optimising the performance of Heating, Ventilation, and Air Conditioning (HVAC) systems. The bricks demonstrate thermal resistance and low thermal transmittance, reflecting their ability to manage heat flow and dissipation effectively. The research focuses on the interaction between the exterior and interior surfaces of the brick set, where the exterior is exposed to a hot environment, and the interior remains cooler. The design incorporates a central air cavity with lower thermal transmittance than solid surfaces. This cavity facilitates a heat dissipation cycle: hotter air rises and is expelled through the top compartment, while cooler air descends, cooling the space. This convective process enhances the overall thermal regulation within the structure. The data explain the discrepancy between predicted and measured thermal performance in interlocking brick systems and how the integrated air cavity addresses these issues. Heat-flux measurements were correlated in a general form to enable designers to account for convection at both the interior and exterior surfaces.

Enhanced performance of lithium-ion battery cathodes using a composite conductive network of CNTs, GQDs, and GNRs embedded in Li₁.₂Mn₀.₅₄Ni₀.₁₃Co₀.₁₃O₂ (LMNCO)

Lithium-rich Li-ion battery cathode materials are known for their high specific capacities and working potential. However, their practical application is limited by the significant decline in discharge potential and capacity during repeated cycling. In this study, we introduce a highly conductive electrode architecture, encapsulating within carbon nanotubes (CNTs), graphene nano-ribbons (GNRs) and graphene quantum dots (GQDs) to mitigate rapid capacity fading and suppress voltage decay. Three Li1.2Mn0.54Ni0.13Co0.13O2 cathode materials were synthesized. The first sample, pristine Li-rich L1.2Mn0.54Ni0.13Co0.13O2, was synthesized using a nitrate co-precipitation method. The second cathode, GNRs-CNTs@Li1.2Mn0.54Ni0.13Co0.13O2, incorporates a mixture of carbon nanotubes and graphene nanoribbons. The third cathode, GQDs:GNRs-CNTs@Li1.2Mn0.54Ni0.13Co0.13O2), further integrates graphene quantum dots within the graphene nanoribbons and carbon nanotubes matrix. The inclusion of highly conductive GNRs-CNTs and GQDs effectively enhances the electrical conductivity of L1.2Mn0.54Ni0.13Co0.13O2, increasing the specific capacity from 246.95 to 316.94 mAhg−1. Additionally, GQDs prevent side reactions and surface phase transitions, thereby improving thermal stability.

Transition mechanism and loss analysis of a separated flow over herringbone riblets in a compressor cascade using the lattice Boltzmann method

Herringbone riblets were regarded as a promising approach to control the separation bubble on the compressor blade. However, the underlying mechanism requires further elucidation. And numerical simulations with body-fitted meshes often face challenges in mesh generation due to the tiny and complex geometries involved. In the present research, high-fidelity simulations using the Lattice Boltzmann Method and Immersed Boundary Method were performed to investigate the effects of herringbone riblets on separated flow in a compressor cascade. At a low Reynolds number of 90 000, a separation bubble appears on the blade suction surface. The application of herringbone riblets on the suction side surface shows that it effectively reduces the bubble length from 0.24c to 0.12c and reduces the loss coefficient by 11%. A counter-rotating mode of secondary flow occurs before the separation, with a near-wall spanwise motion from the divergent region to the convergent region and a compensating flow from the convergent region to the divergent region in the outer layer of the boundary layer. Transition occurs earlier on the suction side surface due to the complex flow patterns. Four different mechanisms are responsible for the earlier transition. Over the divergent region, engulfing of a high momentum fluid from the outer layer to the inner layer of the boundary layer suppresses the separation bubble, forcing a high-momentum passage where an attached boundary layer is observed. This thinner boundary layer leads to an earlier natural transition. Second, the discharge of fluid from the herringbone cusp causes the overflow from the riblet channel beside the divergent line, i.e., overflow transition. Meanwhile, the transition over the converging region is attributed to the accumulation of disturbance. Finally, in the middle region with yawed riblets, transition in a separated shear layer occurs earlier under the influence of adjacent transition mechanisms over the divergent/convergent region. These mechanisms also bring about a serrated structure in the downstream wake. Overall, this research confirms the role of the counter-rotating mode produced by herringbone riblets in separation control and reveals the transition mechanisms for loss production. The findings suggest that proper utilization of herringbone riblets can provide significant improvement on the compressor blade performance.

Strain distribution prediction in UHPC beams using deep learning model

AbstractOver the last three decades, ultra‐high‐performance concrete (UHPC) has emerged as a highly innovative cementitious engineering material. This paper utilizes a distributed fiber optic sensor based on optical frequency domain reflectometry (OFDR) combined with the deep learning model to monitor and predict the strain distribution in UHPC T‐beams subjected to two point bending experiment. These sensors are deployed on the side surfaces of the UHPC T‐beams to capture the strain distribution when subjected to vertical loads, facilitating the determination of crack locations based on strain distribution peaks. While time series modeling is widely used in civil engineering to monitor potential damage using sensor data, its application in tracking and predicting known cracks is less explored. To address this gap, a Long Short‐Term Memory (LSTM) neural network model is developed to forecast the increase in the peak value of the strain distribution prior to structural damage, thus predicting crack initiation. The accuracy of the proposed LSTM model in predicting the UHPC strain distribution was thoroughly investigated. The results demonstrate excellent agreement between the predicted strain distributions and those detected by the ODISI 6000 monitoring system. The root‐mean‐square errors of the model‐predicted strains are generally below 10 με, with an average coefficient of determination (R2) reaching up to 98%, indicating a high degree of accuracy.

Study on the Influence of Wind Load on the Safety of Magnetic Adsorption Wall-Climbing Inspection Robot for Gantry Crane

The maintenance of the surface of steel structures is crucial for ensuring the quality of shipbuilding cranes. Various types of wall-climbing robots have been proposed for inspecting diverse structures, including ships and offshore installations. Given that these robots often operate in outdoor environments, their performance is significantly influenced by wind conditions. Consequently, understanding the impact of wind loads on these robots is essential for developing structurally sound designs. In this study, SolidWorks software was utilized to model both the wall-climbing robot and crane, while numerical simulations were conducted to investigate the aerodynamic performance of the magnetic wall-climbing inspection robot under wind load. Subsequently, a MATLAB program was developed to simulate both the time history and spectrum of wind speed affecting the wall-climbing inspection robot. The resulting wind speed time-history curve was analyzed using a time-history analysis method to simulate wind pressure effects. Finally, modal analysis was performed to determine the natural frequency and vibration modes of the frame in order to ensure dynamic stability for the robot. The analysis revealed that wind pressure predominantly concentrates on the front section of the vehicle body, with significant eddy currents observed on its windward side, leeward side, and top surface. Following optimization efforts on the robot’s structure resulted in a reduction in vortex formation; consequently, compared to pre-optimization conditions during pulsating wind simulations, there was a 99.19% decrease in induced vibration displacement within the optimized inspection robot body. Modal analysis indicated substantial differences between the first six non-rigid natural frequencies of this vehicle body and those associated with its servo motor frequencies—indicating no risk of resonance occurring. This study employs finite element analysis techniques to assess stability under varying wind loads while verifying structural safety for this wall-climbing inspection robot.

Assessment of a Top and Bottom Cooling Strategy for Prismatic Lithium-Ion Cells Intended for Automotive Use

In contemporary vehicle applications, lithium-ion batteries have become a leading option among the diverse array of battery technologies available. This preference is attributed to their advantageous properties, which include low self-discharge rates and no memory effect. Despite these benefits, lithium-ion batteries are not without their challenges. The key issues include a restricted driving range, concerns regarding longevity, safety risks, and prolonged charging durations. Efforts aimed at minimizing the charging duration frequently entail the introduction of elevated currents into the battery, a practice that can significantly elevate its temperature and, in turn, diminish its operational lifespan. Generally, battery packs in electric vehicles are equipped with flat cooling plates located on their side or bottom surfaces, which also serve the dual purpose of providing heating in colder conditions. Nevertheless, this cooling configuration faces difficulties during fast charging and may not efficiently heat or cool the batteries. In this work, a novel thermal management approach is proposed, in which a battery module is cooled not only with a bottom cooling plate but also using another cooling plate in contact with the busbars, located on the top of the battery module. The simulations and experimental tests show that this new configuration demonstrates significant improvements. The thermal time constant is reduced by 47%, enabling faster cooling of the module. Additionally, the maximum temperature reached by the battery during charging with dual cooling is lowered by 6 °C compared to the conventional approach. In this configuration, the top cooling plate acts as a thermal bridge. This is a key advantage that promotes temperature homogenization within the battery module. As a result, it supports an even aging process of batteries, ensuring their longevity and optimal performance.

Examining failures in rubber-cord couplings within ER2 series electric trains

The article provides statistics on failures of rubber-cord couplings of electric trains of the ER2 and ER2T series and of the diesel trains over the past 7 years. According to statistics, over the past 7 years, 107 rubber-cord couplings have failed. Of these, the largest number of cases of failure of rubber-cord couplings occurred on rolling stock of the ER2 series. Examining failed rubber-cord couplings, it was revealed that the cause of its failure was a rupture of the side surface. Replacing a rubber-cord coupling is a labour-intensive and costly process. Accordingly, the question arises: what causes the problem and what measures should be proposed to reduce the failures. For these purposes, the work presents a number of experiments in order to identify possible causes of failure of the rubber-cord coupling. The article presents studies of the heating temperature of rubber-cord couplings in operation on motor cars, as well as a number of studies of failed rubber-cord couplings removed from motor cars. During the research, such parameters as the date of the last repair and the date of failure of the rubber-cord coupling were taken into account. The number of days the motor car was in general operation was taken into account until the failure of the rubber-cord coupling, as well as the mileage of the motor car after the repair. Measurements were carried out of the geometric parameters of the rubber-cord coupling: outer and inner diameter, thickness of the side of the rubber-cord coupling. The torque of the rubber-cord coupling acting at speeds from 5 to 40 km/h, the forces acting in operation on the rubber-cord coupling were calculated, and torsional and shear stresses were also studied and determined. Research was carried out to determine the hardness of the rubber-cord coupling in the temperature range from –20 °C to 0 °C and from 0 °C to +22 °C, as well as from +22 °C to +60 °C. These parameters were taken since a rubber-cord coupling operates under the mentioned conditions. In conclusion, possible reasons for the failure of rubber-cord couplings are given, and recommendations for reduction of their frequency are proposed.

Evaluation of tensile force and mechanical performance in post-tensioned concrete anchorage zones: A combined experimental and numerical study

Anchorage zones are present at the end of the post-tensioned concrete sections. High tensile stresses are produced when the compression force is transmitted through an anchorage mechanism in these members, which causes cracks and fractures in the anchorage zone. The performance of three different anchorage sets, namely rectangular, multi-rectangular, and circular plates, is examined using both experimental and numerical approaches to evaluate the bursting force and stress in the anchorage zone area. An anchorage ratio approach is used to measure jacking force and transverse strains experimentally, while finite element analysis is performed using ANSYS to anticipate the stress and bursting force. The findings reveal that the geometry of the anchorage set has a major impact on the bursting force, but the distribution of bursting stress remains the same. The horizontal orientation of the sheathing pipe can reduce the bursting force by half compared to the vertical orientation. The study compared its results with standard design codes (AASHTO and ACI) and found that the codes overestimate the bursting stress for circular plates and underestimate it for rectangular plates. The study also demonstrates that using an elliptical sheathing pipe can shift the location of bursting from the top to the side surface. Furthermore, inferences are drawn toward the usability of different anchorage sets.

Experimental study of dynamic PCM integration in building walls for enhanced thermal performance in summer conditions

Passively integrating phase change material into the walls to enhance the thermal performance of the building has been a promising solution in recent years. As the PCM has a high latent heat capacity, it leads to damping the high variations of temperature and provides an obvious benefit in energy saving and indoor comfort. However, the traditional passive integration method of the PCM limited the utilization of the PCM. The thermal resistance between the PCM and the indoors restrains the thermal response of the PCM, and it between the PCM and the outdoors reduces the impact of outdoor heating or cooling on the PCM. In this study, a dynamic PCM integration in the building envelope method was proposed and experimentally investigated. A PCM layer and an air layer were combined to be integrated into the wall assembly, which allows the position of the PCM layer and the air layer could be changed to adjust the thermal resistance (air layer) between the PCM and indoors and outdoors. The results showed that this dynamic method can dramatically reduce the indoor temperature and the heat flux across the interior surface of the wall. Compared to the envelope with only static PCM layer configurations, the dynamic PCM provided a reduction of 9.1 % in the indoor average temperature and a reduction of 116.0 % in the peak heat flux during the experiment's three days, as well as the dynamic PCM, exploited more latent heat than the other static configurations. Considering the energy performance, the dynamic integration of PCM showed a 100 % reduction in heat gain through the interior surface compared to the envelope with only a static PCM layer under summer conditions.

Numerical Study of the Influence of Boundary Conditions on Calculations of the Dynamics of Polydisperse Gas Suspension

The work numerically simulates the flow of a polydisperse gas suspension in a channel. The carrier medium was described as a viscous, compressible, heat-conducting gas. The mathematical model implemented a continuum technique for the dynamics of multiphase media, taking into account the interaction of the carrier medium and the dispersed phase. For each component of the mixture, a complete hydrodynamic system of equations of motion for the carrier phase and dispersed phase fractions was solved. The dispersed phase consisted of particles with different sizes of dispersed inclusions. For the carrier medium, homogeneous Dirichlet boundary conditions were specified on the side surfaces of the channel. For fractions of the dispersed phase, boundary conditions for slippage. The influence of the boundary conditions of the flow of the carrier medium on the dynamics of gas suspension fractions has been revealed.

Light-sensitive Ca2+ signaling in the mammalian choroid

The choroid is the thin, vasculature-filled layer of the eye situated between the sclera and the retina, where it serves the metabolic needs of the light-sensing photoreceptors in the retina. Illumination of the interior surface of the back of the eye (fundus) is a critical regulator of subretinal fluid homeostasis, which determines the overall shape of the eye, but it is also important for choroidal perfusion. Noted for having some of the highest blood flow rates in the body, the choroidal vasculature has been reported to lack intrinsic, intravascular pressure-induced (myogenic) autoregulatory mechanisms. Here, we ask how light directly regulates choroid perfusion and ocular fluid homeostasis, testing the hypothesis that light facilitates ocular fluid absorption by directly increasing choroid endothelial permeability and decreasing choroid perfusion. Utilizing ex vivo pressurized whole-choroid and whole-eye preparations from mice expressing cell-specific Ca2+ indicators, we found that the choroidal vasculature has two intrinsically light-sensitive Ca2+-signaling mechanisms: One increases Ca2+-dependent production of nitric oxide in choroidal endothelial cells; the other promotes vasoconstriction through Ca2+ elevation in vascular smooth muscle cells. In addition, we found that choroidal flow, or pressure, modulates endothelial and smooth muscle photosensitivity and trans-retinal absorption of fluid into the choroid. These results collectively suggest that the choroid vasculature exhibits an inverted form of autoregulatory control, where pressure- and light-induced mechanisms work in opposition to regulate blood flow and maintain fluid balance in response to changes in light and dark, aligning with the metabolic needs of photoreceptors.

Andreev Reflection in the Quantum Hall Regime at an Al/InAs Junction on a Cleaved Edge.

We have fabricated a superconductor/semiconductor junction composed of Al and InAs using cleaved edge overgrowth. By exploiting the unique geometry with a thin Al/Pt/Al trilayer formed on the side surface of an in situ cleaved InAs quantum well heterostructure wafer, we achieve a superconducting critical field of ∼5 T, allowing superconductivity and quantum Hall (QH) effects to coexist down to filling factor ν = 3. Andreev reflection at zero magnetic field shows a conductance enhancement limited solely by the Fermi velocity mismatch, demonstrating a virtually barrier-free junction. Bias spectroscopy in the QH regime reveals the opening of a superconducting gap, with the reduced downstream resistance indicating electron-hole Andreev conversion. Our results, obtained in a new experimental regime characterized by a clean edge-contacted junction with a superconducting electrode narrower than the coherence length, open new avenues for both theoretical and experimental studies of the interplay between superconductivity and QH effects.

Preparation of environmentally friendly hydrophobic paper by coating method

Abstract Non-Newtonian viscous fluids such as yogurt, honey, etc., due to their extremely high viscosity and complex fluidity, remain on food containers after use, where adhesion and staining occurs, which is a great inconvenience and causes a lot of wasted resources. Hydrophobic coatings can be an excellent candidate for eliminating liquid waste. Inexpensive wollastonite nanoparticles were used to build rough micro- and nano-structures, and chitosan was used to emulsify rice bran wax to prepare green and low surface energy emulsions. The above two were mechanically mixed to obtain the hydrophobic emulsion, and coated on the paper surface and heat-treated to prepare the hydrophobic paper. Contact angles up to 157.3°. The coating exhibits good self-cleaning properties for a wide range of non-Newtonian viscous food liquids and shows excellent resistance to repeated machine bending and multiple abrasion damages, while maintaining its hydrophobicity. After 40 cycles of friction, the contact angle is 148.1°, which is still close to 150° and has good hydrophobicity. In addition, the coating has great potential for application to the interior surfaces of various food packages to reduce or even eliminate liquid food residues.

Exploring Biomaterial-Based CoolRoofs: Empirical Insights into Energy Efficiency and CO2 Emissions Reduction

The Cool Roof concept, known for its efficiency in summer due to high temperatures during this period, employs a light coating that covers the roof to prevent the absorption of heat and maintain lower indoor temperatures. This study integrates a chemical component with biomaterials to enhance performance and reduce CO2 emissions. The composition investigated in this research is recognized for its durability and ability to lower outside temperatures, thereby mitigating the urban heat island effect. This experimental study evaluates the sustainability of CoolRoofs in a cold room located in Signes, France. Temperature measurements are conducted from 25 September 2023 to 27 July 2024, both with and without the coating, to assess energy performance and CO2 emissions. The selection of the building type ensures optimal performance in both summer and winter. Results show that the maximum outside and inside surface temperatures for a Cool Roof are 48.7 °C and 25.6 °C, respectively, compared to 72.9 °C and 32.2 °C for an uncoated roof. Additionally, implementing a CoolRoof reduces thermal load through the cold room by 56%, while CO2 emissions can be reduced by up to 27.31 kg CO2/m2 over a 20-year period. This study presents a solution for enhancing energy and environmental performance year-round using a resilient composite.

Hydrodynamic analysis of a round-ended caisson in submerging

ABSTRACT Flow around a round-ended caisson in the submerging process is investigated using the k − ω SST turbulent model and the volume of fluid (VOF) method in the present study. Six types of vortex structures around the round-ended caisson are identified, i.e. the neck vortex in front of the cylinder near the free surface, the attached vortex below the free end surface, the tip vortex originating from the free end, the spanwise vortex on the side surface, the U-shaped vortex behind the cylinder and the trailing vortex in the wake. The influence of the free surface, free end and bottom boundary on vortexes are analysed. The physical generation mechanism of vorticity on the free end surface is discussed. Additionally, the drag coefficient increases with Fr when Fr < 1 and decreases with Fr when 1 ≤ Fr ≤ 1.8, and the run-up of the free surface increases with increasing Fr.

Image-driven prediction system: Automatic extraction of aggregate gradation of pavement core samples integrating deep learning and interactive image processing framework

Aggregate gradation plays a crucial role in determining the asphalt pavement performance, necessitating assessment post-construction. Additionally, efficient gradation measurement is vital for the design and construction of reclaimed pavement. This study proposes a methodology for predicting gradation based on imagery. Initially, a scanning device is devised to capture unfolded side surface images of pavement core samples. Subsequently, an interactive software named PyImageJ is developed for image post-processing and acquiring aggregate feature information. A morphological model is then introduced to determine the mass ratios among various grading levels of coarse aggregates with nominal particle sizes greater than 2.36 mm. Finally, sequence prediction models are established to forecast the mass ratios among different grading levels of fine aggregates with nominal particle sizes smaller than 2.36 mm. Simple conversion of the mass ratios can yield the gradation. Experimental results indicate that the Long Short-Term Memory (LSTM) network offers more accurate predictions for the mass ratios of fine aggregates in stone mastic asphalt (SMA-13), with an R-squared value of 0.8985. Conversely, one-dimensional convolutional neural networks (1D CNN) are better suited for predicting the fine aggregate mass ratios in asphalt concrete (AC-20 and AC-25), with R-squared values of 0.9010 and 0.8824, respectively. Visualization results demonstrate that the predicted complete gradation closely aligns with the actual values (R-squared > 0.99), opening a new avenue for evaluating pavement quality.

Crack growth stabilization in the eccentric three-point end-notched flexure test of solid wood using side-grooved samples

A three-point eccentric end-notched flexure (3EENF) test was conducted on Sitka spruce to characterize the Mode II resistance curve (R-curve). To extend the range for stabilized crack growth, grooves were cut along both side surfaces of the sample to reduce the region around the neutral axis. The R-curve was determined by varying the initial crack lengths, and fracture toughness values were measured at both the onset and during growth. Additionally, the effect of side grooves on stabilizing crack growth in the 3EENF test was investigated by comparing numerical simulation results with those from four-point end-notched flexure (4ENF) tests. The grooves effectively stabilized crack growth, and the stabilization range was equivalent to that of the 4ENF test when the initial crack length was appropriately determined. The grooved sample exhibited behavior indicative of a longer crack than the actual length.

ВИЗНАЧЕННЯ СИЛОВОГО НАВАНТАЖЕННЯ НА ВЕРХНЮ ЧАСТИНУ ОРТОПЕДИЧНОГО ТА ПІСЛЯОПЕРАЦІЙНОГО ВЗУТТЯ

The results of determining the force load on the upper part of orthopedic and postoperative shoes, taking into account the bending of the sole, are presented. To determine the force of the load on the top of the postoperative orthopedic shoes, the friction forces between the side surfaces of the shoes and the outer sides of the foot were neglected in the work. Thus, the task was reduced to the compilation of equilibrium equations of a plane system of forces. To determine the unknown forces, it was necessary to compile a system of two equilibrium equations, which will represent the algebraic sums of the projections of all forces on the horizontal and vertical axes, which will be equal to zero. The most common type of deformation acting on shoe parts during manufacturing and operation is stretching and bending. It is the last factor that affects the force load on the upper part of orthopedic and postoperative shoes. Deviation of the human musculoskeletal system from the normal anatomical structure and functioning is one of the serious and widespread ailments of the population. An important factor in reducing the inconvenience caused by this disease is the rational choice of orthopedic shoes. Compliance of orthopedic footwear with the functions that rely on it (supporting the arch of the foot, relieving painful areas, making the limb supportive, increasing the area of ​​foot support) is achieved by a reasoned approach to choosing the design of the product, including in the structure of special, special shape and size details, etc.. Degree compliance of this type of footwear with the real needs of the consumer depends on a complex of factors, and the ability to satisfy them is largely determined by the optimal ratio of indicators of reliability and comfort in the use of upper materials. Textile materials are widely used in the footwear industry for uppers, insoles, insoles, linings, and other parts of various types of footwear. This is caused by their valuable consumer properties, such as low hardness and surface density, pleasant texture, high heat-insulating properties, and a variety of artistic and colorful decoration.

Novel ellipsoid-like granules exhibit enhanced anammox performance compared to sphere-like granules

Anammox granular sludge (AnGS) serves as an important platform for cost-effective nitrogen removal from wastewater. Different to the traditionally sphere-like granules, a novel type of AnGS in a unique ellipsoid-like shape was obtained through enhancing shear force. The ellipsoid-like AnGS significantly exhibited a smaller aspect ratio (-25.1 %) and granular size (-11.8 %), compared to traditional sphere-like AnGS (p < 0.01). Comprehensive comparisons showed that ellipsoid-like AnGS possessed a significantly higher extracellular polymeric substances (EPS) content and strength, as well as an enhanced mass transfer and a higher viable bacteria proportion due to the larger substrate permeable zone (p < 0.01). Additionally, the anammox bacterial abundance (Candidatus Kuenenia) was 12.2 % higher in ellipsoid-like AnGS than in sphere-like AnGS. All these characteristics of ellipsoid-like AnGS jointly increased the specific anammox activity by 29.0 % and nitrogen removal capacity by 22.6 %, compared to sphere-like AnGS. Further fluid field simulation suggested the enhanced flow shear on the side surface of AnGS likely drove the formation of ellipsoid-like AnGS. The higher shear force on the side surface led to an increase of EPS content (especially hydrophobic protein) and elastic modulus, thus constraining lateral expansion. This study sheds light on impacts of granular shape, an overlooked morphological factor, on anammox performance. The ellipsoid-like AnGS presented herein also offers a unique and promising aggregate to enhance anammox performance.

Experimental Investigations on the On-Site Crack Control of Pier Concrete in High-Altitude Environments

Concrete structures in high-altitude environments face many challenges. Establishing concrete crack control methods in high-altitude environments is crucial for enhancing the service capacity of concrete structures. In this study, a multi-field (hydration-temperature–humidity-constraint) coupling model was used to quantitatively assess the cracking risk of pier bodies at high altitude. On-site crack control tests were conducted on pier bodies using a micro-expansion anti-cracking agent to demonstrate the effectiveness of deformation shrinkage compensation in crack control at high altitudes. The results indicated that there was a risk of cracking in the pier body at high-altitude conditions, especially within 0.3 m from the pile cap and ±2.5 m from the center of the pier side surface. Compared with conventional piers, the micro-expansion anti-cracking agent approximately doubled the unit expansion deflection of piers at high temperatures while reducing the unit shrinkage deflection of piers by 11% to 12% at low temperatures. The concrete in conventional pier bodies was in a tension state after long-term hardening, while the concrete treated with the micro-expansive anti-cracking agent was in compression. Therefore, the deformation compensation effect of the micro-expansive anti-cracking agent was significant and reduced the risk of concrete cracking. In addition, early freezing had a significant impact on concrete strength, underscoring the importance of effective temperature control during the early stages of concrete placement in high-altitude environments.