Orthogonal Experiment Analysis Research Articles

Experimental Study on the Longitudinal Motion Performance of a Spherical Robot Rolling on Sandy Terrain

To provide the necessary theoretical models of sphere–soil interaction for the structural design, motion control, and simulation of spherical robots, this paper derives analytical expressions for traction force and driving torque when spherical robots slide and sink into sandy terrain, based on terramechanics and multibody dynamics. Furthermore, orthogonal experimental analysis identifies the load, joint angular acceleration, and maximum joint angular velocity of spherical robots as influencing factors, highlighting that the load significantly affects their longitudinal motion performance. Experimental results indicate that rolling friction and additional resistance on sandy terrain cannot be ignored. The corrected theoretical model effectively replicates the temporal variation of driving torque exerted by spherical robots on sandy terrain. Numerical computations and experimental analyses demonstrate that increasing the radius of the sphere shell, the load, and the slip ratio all lead to increased traction force and driving torque. However, traction force and driving torque begin to decrease once the slip ratio reaches approximately 0.5. Therefore, in the design of spherical robot structures and control laws, appropriate parameters such as load and slip ratio should be chosen based on the established sphere–soil interaction theoretical model to achieve high-quality longitudinal motion performance on sandy terrain.

Optimization of substation enclosure performance and carbon emission analysis based on OED

To explore the thermal performance parameters of substation enclosure parameters and interaction and influence degree, using the DeST software simulation and orthogonal test method to building load minimum as the target parameters, select external wall heat transfer coefficient, roof heat transfer coefficient, outer window heat transfer coefficient and orthogonal test factors, carry out the four factors three level L9 (34) Orthogonal test analysis, studied the influence of each factor and its interaction on the building load, and finally obtained the optimal combination of factors under the comprehensive boundary conditions. At the same time, the correlation between load and outdoor temperature in the optimal scheme of unmanned substation and the carbon emission results before and after optimization are also explored. The results show that through univariate analysis, with the heat transfer coefficient of exterior wall, roof and window, the cumulative cooling load is not linear. Through the orthogonal experimental analysis, the significance of substation building is> roof exterior wall> south Angle> window, and the optimal is A1-B1-C2-D2The annual cumulative building cooling load is 20165.59 kW h, and the peak cooling load appears on July 24. The operating condition of 0 ~ 9kW accounts for 90.6% of the annual operating time. There is a strong linear correlation between the building cooling load and the outdoor temperature (R2=0.65), the energy saving rate of the final optimized scheme is 17.71%, and the carbon saving rate is 26.72%. The research content of this paper provides reference for the renovation of existing buildings and the design of new buildings in substation buildings.

Experimental investigation on longitudinal torsional ultrasonic vibration milling for cortical bone

Efficient bone milling processes, producing high-quality machined surfaces, are crucial for enhancing arthroplasty surgery. This study introduces a novel Longitudinal Torsional Ultrasonically Vibration Milling (LTVUM) technique and conducts a comparative analysis with Conventional Milling (CM). The reduction in average milling force observed during the LTVUM process was systematically recorded. Orthogonal experimental analysis focusing on milling orientation, rotational speed, and feed velocity revealed that LTVUM diminishes the influence of orientation and rotational speed, while amplifying the impact of feed velocity. Subsequent response surface methodology experiments further demonstrated that LTUVM significantly augmented the impact of integrated parameters related to feed velocity. Moreover, LTVUM was found to improve machining surface quality and alter the shear mode. These results have profound implications for the theoretical exploration of LTVUM, supporting the design and development of innovative tools for arthroplasty surgery.

Experimental and numerical investigation of transpiration cooling with gradient porosity layout for the thermal protection of nose cone

Transpiration cooling with liquid phase change has been widely regarded as one of the most promising thermal protection technology for aerospace vehicles. However, when applied to the nose cone with small curvature radius, cooling failure may occur due to the extreme high heat flux and pressure at the stagnation point. In order to deal with this issue, a wedged-shaped nose cone structures with a gradient porosity layout is designed in this work to optimize the coolant distribution in the porous nose cone, and the corresponding transpiration cooling performance with liquid phase change is experimentally and numerically investigated. At last, to meet the thermal protection requirements under different flight conditions as best as possible, an orthogonal experiment and fuzzy gray analysis were carried out to optimize the particle diameter, porosity layout and division interval of the porous nose cone with gradient porosity layout, taking a specific flight condition as an example. The results obtained in this work showed that gradient porosity layout can significantly improve the cooling efficiency at the stagnation point and the temperature uniformity on the outer surface. The porosity has the highest impact on the cooling performance, while the division interval has little impact. By optimizing, the cooling efficiency at the stagnation point can reach 74.5%, and the maximum temperature difference is less than 500K.

Novel hybrid chemical magnetorheological fluid for polishing Ti–6Al–4V alloy

ABSTRACT This study presents a highly efficient chemical and magnetorheological fluid (C-MRF) hybrid polishing process established by using an eco-friendly slurry of malic acid, Fe3O4–SiO2 abrasive particles, and hydrogen peroxide (H2O2) as an oxidant, all mixed with purified water, highlighting its efficacy in a wide range of polishing applications. Herein, the polishing processes of Ti–6Al–4V alloy utilizing C-MRF with on Fe3O4–SiO2 abrasives are detailed, and the polishing performance is assessed by investigating the influence of oxidizing agent H2O2 and acid malic to the surface finish of the Ti–6Al–4V alloy. The linear variable magnetic field by improved Halbach array was proposed to improve the material removal rate and surface quality and create a polishing process with a highly efficient magnetic field source. Single-factor and orthogonal experimental analysis methods are applied to provide the technological parameters factors with varying influences on surface quality and material removal ability.

A novel covalent grafting method between cellulose and ferulic acid through HRP enzyme/acetylacetone/L-Ascorbic acid ternary dual initiator system

In the application of natural dyes, using environmentally and human body harmful metal dyes was still the mainstream dyeing method in the process of cellulose fiber dyeing with natural dyes. This study proposed a new method that can catalyzed the covalent grafting of cellulose materials with Ferulic acid (FA), the ternary system consisting of horseradish peroxidase (HRP), acetylacetone (ACAC) and L-Ascorbic acid (AA). The grafting process of cellulose materials with FA was systematically studied, and the optimal grafting polymerization conditions was determined using orthogonal experimental analysis. In the experiment, it was found that the morphology and structure of cellulose materials significantly affect their grafting polymerization performance with FA, and the change rule of their grafting rate was cotton fabric (3.84%) < cotton yarn (4.54%) < tencel fabric (4.70%) < tencel yarn (53.06%) < cotton cellulose (5.59%) < corn starch (6.70%). The grafted fabrics have excellent color fastness, antibacterial and UV resistance performance. Finally, the structural characteristics of cellulose and its analogues grafted with FA were characterized through FT-IR, 1H NMR, and the possible free radical covalent polymerization mechanism between cellulose materials and FA was analyzed.

Research on the refining and decolorization process of segmented tallow

Using segmented tallow as the experimental material, processed to obtain segmented tallow, and exploring the refining and decolorization process of segmented tallow. Firstly, the orthogonal experimental analysis method was used to investigate the effects of three single factors, namely heating temperature, heating time, and heating speed, on the sensory perception of refined segmented tallow; Secondly, study the decolorization effect of silica gel, activated clay, and attapulgite as decolorizing agents on the segmentation of tallow. The optimal conditions of decolorizing agent for segmenting tallow and oil were systematically investigated from the aspects of decolorizing agent dosage, decolorizing temperature, and decolorizing time. The results showed that under the same conditions, the decolorizing effect of activated clay was the best; Finally, response surface methodology was used to investigate the optimization of three single factors, namely the amount of decolorizing agent, decolorization temperature, and decolorization time, on the decolorization of segmented tallow and fat, in order to obtain the optimal decolorization conditions. The experimental results show that the optimal refining conditions are: heating temperature of 165℃, heating time of 85 minutes, and heating speed of 510 r/min. After sensory evaluation data, the optimal sensory score obtained under these refining conditions is 8.6; Under the conditions of active clay dosage of 3.7%, decolorization temperature of 81℃, and decolorization time of 17 minutes, the decolorization rate of segmented tallow can reach 71.9%.

Optimization of the Preparation Process of Marinated Beef Tendons and The Development of Low-fat Kederan Rubber Tendon Beef Patties

This paper aims to develop a special snack hoof tendon beef patty based on two kinds of local characteristic ingredients, beef tendon and beef. To explore the preparation process of beef tendon and the water retention capacity of beef tendon products, the orthogonal experimental analysis method was used to explore the influence of three single factors on the sensory of the prepared beef tendon, and the three single factors of beef tendon addition, curtai gum addition and salt addition were used to explore the optimization of the water retention of beef tendon beef tendon, and finally the optimal preparation conditions were obtained. The experimental results showed that the optimal preparation conditions were as follows: the marinating temperature was 120°C, the marinating time was 90min, and the simmering time was 5h.The content of beef tendon was 21.153%, the content of cadran gum was 2.154g and the content of salt was 1.498%, and the prepared product had the lowest cooking loss rate of 5.951% and the lowest centrifugal loss rate of 10.155%, so that the beef tendon beef patty achieved better water retention.

Carbon emission measurement of the envelope of a university teaching building in Hefei City

Abstract In response to the challenges posed by global warming, China has formulated dual carbon goals. In this context, the construction industry, a key carbon emitter, is vital for implementing energy-saving and emission-reducing strategies. This study zeroes in on the pivotal role of building envelope structures in carbon emissions, with a focus on a university building in Hefei. Commencing with onsite measurements to gather initial data, the study leverages simulation software to conduct an in-depth analysis. Employing orthogonal experimental design and variance analysis, it meticulously assesses the carbon emissions associated with different materials used in exterior walls, roofs and windows, considering both the material production and building operation phases. The research scrutinizes the impact of these materials on carbon emissions, with a special focus on the performance of seven distinct building retrofit schemes. Key findings of the study underscore that the type and thickness of exterior wall materials substantially influence carbon emissions during the production phase. Conversely, the choice of window materials emerges as more critical in reducing emissions during the building operation phase. The implementation of the various retrofit schemes demonstrates a tangible reduction in overall building carbon emissions. Specifically, these schemes yield a yearly reduction in carbon emissions of 2.96–3.62 tons during operation and a substantial decrease of 30.36–165.97 tons in the production phase, compared to the original structure of the case study building. These insights not only offer practical and viable strategies for the construction industry’s low-carbon development but also provide theoretical underpinnings and references for future building designs and retrofits.

Effect of Blending of Shellac, Carbonyl Iron Powder, and Carbonyl Iron Powder/Carbon Nanotube Microcapsules on the Properties of Coatings

Nine sets of orthogonal experimental samples were prepared by examining four factors: shellac microcapsules, carbonyl iron powder (CIP) microcapsules, CIP/ carbon nanotube (CNT) microcapsules, and primer coating thickness. By testing the morphology and performance of the coating and using the fracture elongation of the coating as an orthogonal experimental analysis, the maximum factor affecting the fracture elongation of shellac, CIP, and CIP/CNT microcapsule coatings was determined. The first two factors that had a significant impact on the fracture elongation of the coating were the content of CIP/CNT microcapsules and shellac microcapsules. In order to further optimize the coating performance, important factor experiments were conducted, using the content of CIP/CNT microcapsules and shellac microcapsules as variables. It was found that the coating had the best performance when the content of CIP/CNT microcapsules was 7.0% and the content of shellac microcapsules was 4.0%. The optical properties of coatings with added shellac, CIP, and CIP/CNT microcapsules were tested, and the color difference and glossiness of the coatings showed little change. The mechanical properties of coatings with added shellac, CIP, and CIP/CNT microcapsules were tested. The blending of the three types of microcapsules enhanced the toughness of the coating to a certain extent, and suppressed the generation of micro-cracks, demonstrating a good self-healing effect. The electromagnetic-absorption performance of coatings with added shellac, CIP, and CIP/CNT microcapsules was tested. The blending of shellac, CIP, and CIP/CNT microcapsules exhibited two effective bands of electromagnetic absorption and a good absorption performance at a relatively wide frequency range. The combination of shellac, CIP, and CIP/CNT microcapsules endows the fiberboard surface with self-healing and electromagnetic-absorption functions, while maintaining the original performance of the water-based coating. The results can be used for application of surface coatings on wooden materials with dual functions of self-healing and electromagnetic absorption.

Optimization of diesel oxidation catalyst for enhanced emission reduction in engines

With tightening emission regulations and the advent of Zero-Carbon targets, curbing emissions from engines has become imperative. To enhance the emissions reduction of engines, a diesel oxidation catalyst (DOC) inserted within a three-layer porous media is proposed. Effects of Pd/Pt blended ratios, porous media settings, and boundary conditions on pollutant conversion are simulated and analyzed. The results indicate that increasing the Pd/Pt blended ratio and reducing the porosity favor the conversion of CO and C3H6 but hinder the generation of NO2, and there exists a balancing effect of porosity and multi-layer porous media on emission conversion. With mean porosity augment from 0.4 to 0.6, NO conversion rate is improved by 2.1 % in the DOC with incremental porous media setting at Vin = 10 m/s, Tin = 550 K, and 100 % Pt. Moreover, the differences in conversion rates are enlarged with an increased Pd catalyst content, by 3.2 %, 5.9 %, 9.6 %, and 10.6 % respectively. Besides, 50 sets of DOCs are simulated, using orthogonal experiment analysis to optimize the boundary conditions and DOC setting. The maximum conversion rate is achieved when Vin = 10 m/s, Tin = 600 K, mO2 = 0.04, and Pd/Pt catalyst blended ratio and porosity is 100%Pt+1/4 + 1/4 and 0.5 + 0.4+0.4 in porous media.

Design and Numerical Simulation Study of Film Rod Reparation Device for Residual Film Recycling Machine

For the residual film recycling machine work, after the recovery of residual film, cotton stalks, crushed soil, and other impurities are not easy to separate; it is challenging to realize the secondary use of the problem. A waste film and impurity wind selection device were designed to recognize waste film recycling and separate soil film rods. The overall structure and working principles of the machine are described. A three-dimensional computational fluid dynamics model of a film rod separation device was developed. The flow field within the film rod separation unit was analyzed by numerical simulation using 2023 R1 ANSYS Fluent software. Based on the differences of impurities such as residual film, soil, and cotton stalks in terms of density, suspension velocity, and their characteristics, the pressure distribution and velocity distribution of the internal flow field of soil, residual film, and cotton stalks at the site were investigated. The air inlet velocity, screen cylinder rotation, and main shaft rotation velocity were changed. Experiments were conducted to obtain wind selection parameters for suitable soil, residual film, and cotton stalk separators. Analysis of orthogonal experiments, polar variance of analysis, and analysis of variance yielded a better combination of working parameters: when the drum sieve velocity is 25 r/min, the spindle velocity is 35 r/min, and inlet wind velocity is 14 m/s, after the separation of residual film impurity rate of 8.9%. The results of the study can provide a theoretical basis for the development of film separation equipment.

Effect of textured parameters on tribological properties of hydrodynamic journal bearing

PurposeThis study aims to improve the tribological properties of hydrodynamic journal bearing via surface texture, as well as the wear and antifriction mechanisms of textured bearing were represented. It provides a design direction for solving the tribological problem of rotor-bearing system.Design/methodology/approachIn this paper, the variation of surface texture parameters (e.g. texture diameter, d; area density, sp; and depth, hp) were analyzed based on finite difference method. The optimal surface texture parameters were obtained by designing orthogonal experiments, and the relationship between friction and wear properties and microstructure was studied via combining electron probe microanalyzer, scanning electron microscope, X-ray diffractometer and friction and wear testing machine.FindingsDimensionless film pressure P increased as the d increased, whereas P first increased and then decreased as the sp and hp increased, and the maximum P was got as sp = 15% and hp = 25 µm, respectively. The friction coefficient of textured surface with suitable parameters was effectively reduced and the textured surface with the best antifriction effect was 5#. Orthogonal experimental design analysis showed that the influence order of factors on friction coefficient was as follows: sp > sp × d > d > d × hp > hp > sp × hp and the friction coefficient first decreased and then increased as the sp, d and hp increased. In addition, the friction and wear mechanism of textured bearing were three body friction and abrasive wear as the matrix structure and hard phase were a single β phase and Mn5Si3, respectively. While the antifriction mechanism of textured surface was able to store abrasive particles and secondary hydrodynamic lubrication was formed.Originality/valueThe sample with reasonable texture parameter design can effectively reduce friction and wear of hydrodynamic journal bearing without reducing the service life, which can provide a reference for improving the lubrication performance and mechanical efficiency of rotor-bearing system.

Preparation of low-carbon and environmentally friendly non-sintered ceramsite (NSC) employing steel slag, GGBS and fly ash: Experiment and performance regulation

Using solid waste to prepare lightweight aggregate non-sintered ceramsite (NSC) with excellent performance is a major breakthrough in the utilization of solid waste. In this study, low-carbon environment-friendly NSC was prepared by employing steel slag, ground granulated blast-furnace slag (GGBS) and fly ash as the main matrix materials for the preparation of NSC, using cement as binder, and adding water glass and dihydrate gypsum as alkali activator. Through the comparative analysis of single factor experiment and orthogonal experiment, the performance of NSC was explored and analyzed, and the best preparation scheme of NSC with excellent performance was obtained. The composition and structural mechanism of NSC were observed and analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM) to explore and confirm the performance of NSC. Considering the cylinder compressive strength, bulk density, specific surface area and 1-hour water absorption, it was determined that when the water consumption is 35%, the cement dosage is 10%, and the steel slag: GGBS and fly ash: GGBS = 1:1, the prepared NSC has the best performance. The cylinder compressive strength of NSC could reach 4.2 MPa and 12.4 MPa respectively, and 1-hour water absorption was 13%. This indicates that the comprehensive performance of NSC prepared by fly ash + GGBS as matrix material was better. The steam curing method is more beneficial to the development of NSC strength. Considering the actual situation, it is more appropriate to control the steam curing time at 12 h. The optimum dosage of alkali activator in NSC was determined by orthogonal test analysis: water glass 3%, dihydrate gypsum 5%, and the optimum steam curing temperature was determined to be 60 °C. This work realized the utilization of steel slag with low activity and large doping, which was conducive to fully studying and understanding the recycling of solid waste, and solved the problem that steel slag was difficult to be used and treated for a long time to a certain extent.

Optimization, formation, and evolution of the photoinduced curing gradients and in-situ lamellar gaps in additive manufacturing of ZrO2 ceramics: From curing to sintering behaviors

The photoinduced curing gradients and in-situ lamellar gaps were related to the three-dimensional curing mechanism of stereolithography and researched in this work. Based on the photocuring mathematic theories presented by our team, photoinduced curing gradients were influenced by printing parameters such as laser power and frequency, scanning angle, and printing thickness. Among these curing gradients, the inadequate curing area was the main factor affecting the surface quality and physical properties of ceramics. The in-situ lamellar gaps were derived from the inadequate curing area. The lamellar gap size of green bodies was enlarged in brown bodies (sintering at 1170 ℃) and shrunk in sintered bodies (sintering at 1500 ℃). The correlations between the surface quality and printing parameters were clarified by establishing mathematical formulations of the lamellar gap size. Furthermore, anisotropic volume shrinkage, anisotropic surface topography, and density and hardness evolutions were associated with the wrapped particle density differences induced by the photoinduced curing gradients. Finally, the optimal printing parameters (75% of laser power, laser frequency of 150 kHz, scanning angle of 90º, printing thickness of 25 μm, and scanning speed of 2.5 m/s) were obtained by the orthogonal experimental analysis. This study provides a distinct understanding of the high-quality forming and extreme-performance manufacturing of stereolithography.

Influence of Coal Gangue Powder on the Macroscopic Mechanical Properties and Microstructure of Recycled Aggregate Concrete.

The construction and coal industries generate substantial industrial waste, including coal gangue and construction and demolition (C&D) waste, leading to environmental pollution and high disposal costs. Integrating recycled aggregates (RAs) and coal gangue powder (CGP) into concrete is an effective approach for waste management. However, CGP can affect the performance of traditional recycled concrete. This study primarily aims to optimize the utilization of RAs and CGP while maintaining concrete performance. They utilized orthogonal experimental designs and microscopic characterization techniques, including scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). Orthogonal experimental analysis indicated that with a water-cement ratio (WCR) of 0.5 and replacement rates of 10% for CGP and 60% for RA, compressive and splitting tensile strengths reached 73.6% and 77.4% of ordinary C30 concrete, respectively. This mix proportion minimizes strength decline in coal gangue powder-recycled aggregate concrete (CGP-RAC) while maximizing recycled material replacement. Microscopic analysis revealed that CGP increased the Ca/Si ratio in cement paste, impeding hydration reactions, resulting in a looser internal structure and reduced concrete strength. These findings are anticipated to provide fresh theoretical insights for solid waste recycling and utilization.

Effect of Shellac Microcapsules Blended with Carbonyl Iron Powder and Carbon Nanotubes on the Self-Healing and Electromagnetic Wave Absorption Properties of Waterborne Coatings on Fiberboard Surface

An orthogonal experiment was conducted to prepare nine different coatings by changing four influencing factors of shellac microcapsule content, carbonyl iron powder (CIP) content, the content of carbon nanotubes (CNTs), and primer coating thickness. By testing the morphology and performance of the shellac microcapsules, CIP, CNT blended coatings (SCCBC), and using the elongation at tensile failure of the SCCBC as the orthogonal experimental analysis, it was determined that the biggest factor affecting the elongation at tensile failure of SCCBC was the shellac microcapsule content. With the aim of further optimizing the properties of the SCCBC, a single-factor experiment was performed using shellac microcapsule content as the sole variable, and it was determined that the SCCBC exhibited optimal performance when shellac microcapsule content reaches 4.2%. The optical properties of SCCBC were tested, showing that there were minor fluctuations in the glossiness and color difference of the SCCBC. The mechanical properties of SCCBC were tested. The presence of shellac microcapsules can contribute to an improvement of the SCCBC toughness, restraining the formation of microcracks, and have a certain self-healing effect. The electromagnetic wave absorption properties of the mixed powder of shellac microcapsules, CIP and CNTs were tested. The CIP and CNTs can enhance the electromagnetic wave absorption properties of the waterborne coating, but the electromagnetic wave absorption properties were weaker in low-frequency bands. The SCCBC on the surface of fiberboard not only have a self-healing effect, but also have a certain electromagnetic wave absorption function through the mixing of shellac microcapsules, CIP, and CNTs, expanding the application range of waterborne coatings for wood.

Optimization of engineering parameters of deflagration fracturing in shale reservoirs based on hybrid proxy model

Engineering parameter optimization of deflagration fracturing in shale reservoirs is operated with single factor analysis and orthogonal experimental design analysis. There are problems of the difficulty to search the global optimal solution, time-consuming optimization and low computation efficiency. To resolve these problems, a method of optimizing engineering parameters of deflagration fracturing based on the hybrid proxy model was proposed in this paper. The parameters with significant effects on deflagration fracturing were selected as variables, and the models for prediction of reservoir burst degree and stimulated area were established based on Radial Basis Function model, Kriging interpolation model and eXtreme Gradient Boosting regression model respectively. A hybrid proxy model based on the roulette method was established by integrating the priorities of these three models. Then, a multi-objective optimization method of deflagration fracturing based on the hybrid proxy model and was established by integrating the Nondominated Sorting Genetic algorithm II with the engineering parameters as variables and the maximum stimulated area and minimum burst degree as objectives. Optimal design of the deflagration fracturing scheme was achieved. The results show that the hybrid proxy model can accurately predict the evaluation index of the fracturing results in vertical and horizontal wells, and the prediction accuracy is maintained at about 0.9. At the same time, compared with numerical model, the proposed method greatly saves the calculation time. The method proposed by this paper provides the solution to the problem of multi-objective optimization of deflagration fracturing engineering parameters, weighs the reservoir failure degree and the stimulation range, and provides guidance for field operation.

Effect of Chemical Admixtures on the Working Performance and Mechanical Properties of Cement-Based Self-Leveling Mortar

In this work, the effect of cellulose ether (CE), tartaric acid (TA), and polycarboxylate superplasticizer (PCE) on the working performance and mechanical properties of cement-based self-leveling mortar is investigated. According to the orthogonal experiment analysis, TA is identified as the most influential factor affecting the working performance, as indicated by factors such as fluidity, fluidity loss, and viscosity. Upon conducting a comprehensive assessment of the working performance and mechanical properties, the optimal parameters are found to be CE = 0.6 wt.‰, TA = 0.5 wt.‰, and PCE = 2.0 wt.‰. A univariate test highlights that that the working performance improves with the higher TA dosages. Specifically, the exponential reduction of fluidity loss corresponds with an increased TA content. Regarding the mechanical properties of cement-based self-leveling mortar, the compressive and flexural strength exhibit enhancement when the TA dosage remains below 0.4 wt.‰ at the early stage, implying that TA has some influence on the hydration process. Impressively, the 1 d compressive and flexural strengths surpass 7 MPa and 2 MPa, respectively, ensuring the viability of subsequent construction activities. Through an analysis of hydration heat, the effect mechanism of TA on the cement-based self-leveling mortar is derived. The result shows that the addition of TA decelerates the hydration process within the initial 10 h, followed by acceleration in the subsequent 20 h to 30 h. Consequently, this delayed formation of the early hydration product, ettringite, contributes to a more porous structure in the slurry, with low friction leading to a better working performance. A large number of hydration products, such as alumina gel and calcium–silicon–hydrate gel, presented in the hardened paste results in the good mechanical properties at 1 d. This study may lay a foundation for the optimization of the dosage of chemical admixtures in the self-leveling mortar and high-performance cement-based materials, and also impart valuable insights for practical applications extending to the realm of building construction and decoration.

Optimal Design of and Experiment on a Dual-Spiral Ditcher for Orchards

This study aimed to design a counter-rotating dual-axis spiral ditcher to address the problems of the lack of ditching models, low ditching quality, and high power consumption in ditching operations in hilly and mountainous orchards. By establishing a discrete element simulation model of the interaction between the dual-spiral cutter and the soil, we analyzed the effects of different operating parameters on the ditching performance and power consumption to explore the mechanism of the interaction between the soil-engaging components and the soil; meanwhile, according to the simulation data, we took the forward speed, cutter speed, and ditching depth as the experimental influencing factors, and we took the ditching qualification rate and power consumption as the experimental indicators. Then, through a three-factor and three-level orthogonal experimental analysis, we obtained the optimal parameter combination. Based on the optimized simulation results, a prototype ditcher was fabricated, and the results of a soil trough test showed that the ditcher had a stable ditching performance, an average ditching qualification rate of 91.4%, an average soil crushing rate of 72%, and a ditching adjustment structure that could adjust the ditching depth and width within the ranges of 15–25 cm and 10–20 cm, respectively. The optimized ditcher had high efficiency, stability, and energy savings during its operation, and it was able to meet the agronomic requirements for ditching operations. This study provides a design basis and technical support for dual-spiral trial ditching operations.