Search Results (194)

Cutting beech plywood using abrasive water jet (AWJ) technology represents a significant area of research due to increasing demands for precision, quality, and environmental sustainability in manufacturing processes within the woodworking industry. AWJ technology enables non-contact cutting of materials without causing thermal deformation or mechanical damage, which is crucial for preserving the structural integrity and mechanical properties of the plywood. This article investigates cutting beech plywood using technical methods using an abrasive water jet (AWJ) at 400 MPa pressure, with Australian garnet (80 MESH) as the abrasive material. It examines how abrasive mass flow rate, traverse speed, and material thickness affect AWJ lag, which in turn influences both cutting quality and accuracy. Measurements were conducted with power abrasive mass flow rates of 250, 350, and 450 g/min and traverse speeds of 0.2, 0.4, and 0.6 m/min. Results show that increasing the abrasive mass flow rate from 250 g/min to 350 g/min slightly decreased the AWJ cut width by 0.05 mm, while further increasing to 450 g/min caused a slight increase of 0.1 mm. Changes in traverse speed significantly influenced cut width; increasing the traverse speed from 0.2 m/min to 0.4 m/min widened the AWJ by 0.21 mm, while increasing it to 0.6 m/min caused a slight increase of 0.18 mm. For practical applications, it is recommended to use an abrasive mass flow rate of around 350 g/min combined with a traverse speed between 0.2 and 0.4 m/min when cutting beech plywood with AWJ. This balance minimizes jet lag and maintains high surface quality comparable to conventional milling. For thicker plywood, reducing the traverse speed closer to 0.2 m/min and slightly increasing the abrasive flow should ensure clean cuts without compromising surface integrity. Full article

The textile industry is progressively shifting towards more sustainable solutions, particularly in the field of printing technologies. This study reports the development and evaluation of water-based pigment inks formulated with bio-based pigments derived from intermediates produced via bacterial fermentation. Two pigments—indigo (blue) and quinacridone (red)—were incorporated into ink formulations and applied on cotton and polyester fabrics through valve-jet inkjet printing (ChromoJet). The physical properties of the inks were analyzed to ensure compatibility with the equipment, and printed fabrics were assessed as to their color fastness to washing, rubbing, artificial weathering, and artificial light. The results highlight the good performance of the bio-based inks, with excellent light and weathering fastness and satisfactory wash and rub resistance. The effect of different pre-treatments, including a biopolymer and a synthetic binder, was also investigated. Notably, the biopolymer pre-treatment enhanced pigment fixation on cotton, while the synthetic binder improved wash fastness on polyester. These findings support the integration of biotechnologically sourced pigments into eco-friendly textile digital printing workflows. Full article

HPMC, regulating slurry properties, is widely used in cement-based materials. Research on the application of HPMC in gangue slurry is still in its early stages. Moreover, the interactive effects of various factors on gangue slurry performance have not been thoroughly investigated. The work examined the effects of slurry concentration (X₁), maximum gangue particle size (X₂), and HPMC dosage (X₃) on slurry performance using response surface methodology (RSM). The microstructure of the slurry was characterized via scanning electron microscopy (SEM) and polarized light microscopy (PLM), while low-field nuclear magnetic resonance (LF-NMR) was employed to analyze water distribution. Additionally, industrial field tests were conducted. The results are presented below. (1) X₁ and X₃ exhibited a negative correlation with layering degree and slump flow, while X₂ showed a positive correlation. Slurry concentration had the greatest impact on slurry performance, followed by maximum particle size and HPMC dosage. HPMC significantly improved slurry stability, imposing the minimum negative influence on fluidity. Interaction terms X₁X₂ and X₁X₃ significantly affected layering degree and slump flow, while X₂X₃ significantly affected layering degree instead of slump flow. (2) Derived from the RSM, the statistical models for layering degree and slump flow define the optimal slurry mix proportions. The gangue gradation index ranged from 0.40 to 0.428, with different gradations requiring specific slurry concentration and HPMC dosages. (3) HPMC promoted the formation of a 3D floc network structure of fine particles through adsorption-bridging effects. The spatial supporting effect of the floc network inhibited the sedimentation of coarse particles, which enhanced the stability of the slurry. Meanwhile, HPMC only converted a small amount of free water into floc water, which had a minimal impact on fluidity. HPMC addition achieved the synergistic optimization of slurry stability and fluidity. (4) Field industrial trials confirmed that HPMC-optimized gangue slurry demonstrated significant improvements in both stability and flowability. The optimized slurry achieved blockage-free pipeline transportation, with a maximum spreading radius exceeding 60 m in the goaf and a maximum single-borehole backfilling volume of 2200 m³. Full article

Accurately monitoring terrestrial water storage (TWS) variations is essential due to global climate change and growing water demands. This study investigates TWS changes in Oregon, USA, using Global Navigation Satellite System (GNSS) data from the Nevada Geodetic Laboratory, Gravity Recovery and Climate Experiment (GRACE) level-3 mascon data from the Jet Propulsion Laboratory (JPL), and Noah model data from the Global Land Data Assimilation System (GLDAS) data. The results show that the GNSS inversion offers superior spatial resolution, clearly capturing a water storage gradient from 300 mm in the Cascades to 20 mm in the basin and accurately distinguishing between mountainous and basin areas. However, the GRACE data exhibit blurred spatial variability, with the equivalent water height amplitude ranging from approximately 100 mm to 145 mm across the study area, making it difficult to resolve terrestrial water storage gradients. Moreover, GLDAS exhibits limitations in mountainous regions. The GNSS can provide continuous dynamic monitoring, with results aligning well with seasonal trends seen in GRACE and GLDAS data, although with a 1–2 months phase lag compared to the precipitation data, reflecting hydrological complexity. Future work may incorporate geological constraints, region-specific elastic models, and regularization strategies to improve monitoring accuracy. This study demonstrates the strong potential of GNSS technology for monitoring TWS dynamics and supporting environmental assessment, disaster warning, and water resource management. Full article

The enduring manufacturing goals are increasingly shifting toward ultra-precision manufacturing and micro-nano fabrication, driven by the demand for sophisticated products. Unconventional machining processes such as electrochemical jet machining (ECJM), electrical discharge machining (EDM), electrochemical machining (ECM), abrasive water jet machining (AWJM), and laser beam machining (LBM) have been widely adopted as feasible alternatives to traditional methods, enabling the production of high-quality engineering components with specific characteristics. ECJM, a non-contact machining technology, employs electrodes on the nozzle and workpiece to establish an electrical circuit via the jet. As a prominent special machining technology, ECJM has demonstrated significant advantages, such as rapid, non-thermal, and stress-free machining capabilities, in past research. This review is dedicated to outline the research progress of ECJM, focusing on its fundamental concepts, material processing capabilities, technological advancements, and its variants (e.g., ultrasonic-, laser-, abrasive-, and magnetism-assisted ECJM) along with their applications. Special attention is given to the application of ECJM in the semiconductor and biomedical fields, where the demand for ultra-precision components is most pronounced. Furthermore, this review explores recent innovations in process optimization, significantly boosting machining efficiency and quality. This review not only provides a snapshot of the current status of ECJM technology, but also discusses the current challenges and possible future improvements of the technology. Full article

The jet-type self-cleaning screen filter integrates industrial jet-cleaning technology into the self-cleaning process of screen filters in the drip irrigation system, which has the advantages of low water consumption, high cleaning capacity, and wide applicability compared to traditional filters. However, its commercialization faces challenges as the optimal jet cleaning mode and optimization method have not been determined. This study proposes a framework that combines computational fluid dynamics (CFD), artificial neural networks (ANN), and genetic algorithms (GA) for optimizing jet-cleaning parameters to improve the performance. The results show that, among the main influencing parameters of the nozzle, the incident section diameter d and the V-groove half angle β have the most significant effects on the peak wall shear stress, action area, and water consumption for cleaning. The ANN has a higher accuracy in predicting the performance (R² = 0.9991, MAE = 9.477), and it can effectively replace the CFD model for predicting the jet-cleaning performance and optimizing the parameters. The optimization resulted in a 1.34% reduction in the peak wall shear stress, a 16.82% reduction in cleaning water consumption, and a 7.6% increase in the action area for the optimal model compared to the base model. The optimization framework combining CFD, ANN, and GA can provide an optimal cleaning parameter scheme for jet-type self-cleaning screen filters. Full article

Reducing CO₂ emissions in general aviation is a critical challenge, where battery electric and fuel cell technologies face limitations in energy density, cost, and robustness. As a result, hydrogen (H₂) dual-fuel combustion is a promising alternative, but its practical implementation is constrained by abnormal combustion phenomena such as knocking and pre-ignition, which limit the achievable H₂ energy share. In response to these challenges, this paper focuses on strategies to mitigate these irregular combustion phenomena while effectively increasing the H₂ energy share. Experimental evaluations were conducted on an engine test bench using a one-cylinder dual-fuel H₂ kerosene (Jet A-1) engine, utilizing two strategies, including water injection (WI) and rising the air–fuel ratio (AFR) by increasing the boost pressure. Additionally, crucial combustion characteristics and emissions are examined and discussed in detail, contributing to a comprehensive understanding of the outcomes. The results indicate that these strategies notably increase the maximal possible hydrogen energy share, with potential benefits for emissions reduction and efficiency improvement. Finally, through the use of 0D/1D simulations, this paper offers critical thermodynamic and efficiency loss analyses of the strategies, enhancing the understanding of their overall impact. Full article

In the field of abrasive-water-jet polishing technology, the influence of nozzle geometry on nozzle wear and internal-structure erosion in abrasive-water-jet polishing technology is studied, and the nozzle design is optimized through experiments and a numerical simulation to improve the stability and efficiency of the abrasive jet. The mathematical model between the cross-sectional area of the nozzle and the dimensionless length of the nozzle is established, as well as the variation in the static pressure of the nozzle and the length of the nozzle. Through Fluent simulation, it is found that when the nozzle length is 12 mm, the abrasive-phase acceleration is sufficient and the erosion intensity is minimal. After 480 h of erosion experiments, the erosion profile of nozzle cavity was detected. The results show that the erosion strength of the 12 mm nozzle is the least, followed by the 6 mm nozzle, and the 18 mm nozzle is the strongest, which is consistent with the simulation results. Full article

Water jet repair technology, used for gas extraction boreholes, is an effective way to improve the effect of gas extraction. Nevertheless, the effects water jets have on the repair of gas extraction boreholes are still ambiguous. To investigate the characteristics of coal breaking using water jets in gas extraction boreholes and their repair effectiveness, a mathematical model for water jet coal breaking was established and a method for determining the depth of coal breaking using water jets was proposed. The coal-breaking depth, stress distribution law, and damage distribution law under the influence of water jet pressure, jet target distance, and coal strength were investigated using numerical simulations so as to make clear the repair effects of water jets on gas extraction boreholes. The outcomes indicate the following: the depth of coal breakage increases linearly with the increase in jet pressure; the depth of coal breakage decreases inversely proportional to the increase in coal body strength; and a reverse linear correlation exists between the water jet coal-breaking depth and the jet target distance. The extent of the influence exerted by coal strength, jet pressure, and jet target distance on the depth of coal breakage diminishes successively. The scope of damage caused by water jet flow to the rock surrounding gas extraction boreholes is limited. The coal-breaking depth model, coal body stress distribution model, and damage distribution model under the influence of jet pressure, coal body strength, and jet target distance were obtained using fitting. The research findings can offer a theoretical basis and technical support for enhancing the utilization efficiency of coal seam gas extraction boreholes. Full article

The use of 3D roughness parameters is increasingly gaining ground in various areas of engineering, especially in academic research. In many cases, however, these studies primarily cover the illustration of the character of the surfaces, the interpretation of areal numerical roughness values is often disputed. The goal of this paper is to examine how the 2D and 3D roughness parameters change in the case of anisotropic surfaces, such as surfaces cut with an abrasive water jet. For this purpose, abrasive water jet cutting experiments were performed on AlMgSi0.5 aluminum alloy using different technological parameters. After the experiments, two amplitude-type 3D roughness parameters (S_a and S_z) of the cut surface and four profile parameters (R_a, R_z for roughness and P_a, P_z for raw profile) were measured at five different depths. Our conducted research indicates that the 3D parameters represent a kind of average value for certain roughness characteristics and a maximum value for others. The paper also reports on how these roughness characteristics change as a function of feed speed. Full article

High-pressure abrasive water jet (HP-AWJ) cutting is a prominent technology for processing a wide variety of materials. The structural parameters of the nozzle are important for the cutting performance of the HP-AWJ. This paper combines an abrasive particle kinetic energy model and a wall wear model of the nozzle to determine the multi-phase flow of a HP-AWJ nozzle. The flow field structure of the nozzle was optimized using a parametric multi-objective structure optimization design method. A Multi-Objective Heat Transfer Search (MOHTS) was utilized to generate the corresponding mathematical regression model for multiple response results, and the optimal solution sets of Pareto values were further obtained. The optimal HP-AWJ structural parameters could be selected according to the weight influence of multiple response indicators. Full article

The highway network is densely distributed in the southeast coast of China. Highway subgrades passing through soft soil areas often produce large settlements, resulting in pavement cracking, bridgehead jumping, and other diseases. In order to study the effect of three trenchless treatment technologies of oblique jet grouting pile (JGP), lateral displacement limiting pile (LDLP), and load reducing pipe (LRP), centrifugal model tests were carried out under three treated conditions and without treatment. Based on the data of pore water pressure and settlement in the range of the half embankment model and outside the embankment, the settlement characteristics of highway soft soil foundation during the test simulation were studied, and the characteristics of different treatment methods were compared. The high level of pore water pressure corresponds to the rapid development of settlement. The average settlement during the existing operation period accounts for 96.7% of the total settlement of the simulation period, and the settlement does not converge. The methods can effectively inhibit the development of settlement, and each has its own characteristics: the LRP method does not involve foundation treatment, so its settlement characteristics are closest to that without treatment. The LDLP method can obviously limit the settlement within the embankment range and the pore water dissipation. The JGP method enhances the synergistic deformation ability of the embankment and significantly decreases the differential settlement. Full article

This article presents findings from ongoing research on improving the efficiency of leaching salt caverns for brine production and creating storage spaces for gases or fuels. Previous studies of the authors highlighted the potential of modifying conventional technology by employing a high-pressure water jet to carve niches in salt rock. Current research aims to define precise niche parameters using innovative and enhanced Jet Cavern Technology (JCT). Our research identified improvements in leach efficiency across various configurations and quantities of niches. By analyzing three salt types—pink, spiz, and crystalline—it was demonstrated that creating a niche perpendicular to the well axis significantly reduces the time to achieve saturated brine by approximately 38%, particularly during the initial construction phase. Further adjustments in niche dimensions, spacing, or spatial positioning can improve cavern construction rates by up to 20% over standard methods. This study quantified the correlation between the advancement of the process and the rate of increase in the salt content in the brine. Accelerated brine saturation facilitates cavern construction and mitigates environmental concerns associated with the discharge of unsaturated brine. The adoption of this new technology is crucial for the expansion of renewable energy sources and the associated storage requirements. Full article

The efficiency and safety of salt cavern gas storage are critically dependent on the construction speed and structural integrity of the cavern. To tackle these issues, this paper presents a novel Extended Rapid Cavity Creation Device that employs water jet technology to effectively reduce the construction time and enhance control over the cavity structure. A simulation analysis of the device’s external flow field was conducted using FLUENT software. An experimental system was developed to investigate the effects of nozzle inclination and rotation speed on the dissolution of salt rock samples. The simulation and experimental results indicate that the intensity and shape of turbulence have a significant impact on the formation of the internal cavity within the salt rock. Specifically, a 45° nozzle inclination generates a conical turbulent flow that significantly enhances the mass transfer efficiency. As the rotation speed increases, the intensity and range of turbulence in the external flow field gradually extend towards the centre of the salt cavern cavity. This turbulence promotes the dissolution of salt rock, significantly reducing the ‘step’ structure at the bottom of the cavity. This study provides a valuable foundation for the further optimization of device design and a deeper understanding of the dissolution mechanism. Full article

This study investigates the development and application of climate friendly processes in the foundry industry, particularly with regard to the use of inorganic binders to reduce emissions and pollution. An inorganic binder system based on water glass, which is used in 3D printing technology for the production of sand molds and core, is being tested and the possibility of determining a kinetic model for the curing kinetics of sodium silicate as an inorganic binder is investigated. The aim is to use a kinetic model to better describe the microwave process currently required in binder jetting for drying the binder and catalyzing the chemical reaction of the binder during curing. For sodium silicate in particular, there is still no scientific knowledge available in this respect, which is why basic investigations based on thermogravimetry or heat flow difference calorimetry must first be carried out. In this way, it should be possible to simulate the drying process in the microwave, which has so far been based on empirical values, in order to maximize the efficiency of this process and also the quality of the components. The results indicate that the weight loss and weight changes depend on the heating rates and that a heating rate of 30 K/min is not sufficient to fully cure the sample at 500 °C. The thermogravimetric analysis (TGA) shows that the fastest weight loss occurs at the beginning of the measurement, indicating a partial pre-curing of the sample before the measurement. From the measurements, an average activation energy of 144.18 kJ/mol could be determined using the Friedman method and 123.36 kJ/mol and 123.31 kJ/mol using the Ozawa–Flynn–Wall and Kissinger–Akahira–Sunose methods, respectively. Measurements of the heat flow at a heating rate of 30 K/min indicate partially exothermic reactions during the curing process. Full article