The proposed research aims to accomplish an improved A* algorithm for mobile robots in complex environments. In this novel algorithm, the guidance of environment information is added to the evaluation function to enhance the adaptability of the algorithm in complex environments. Additionally, to solve the problem of path smoothness, the optimal selection rules for child nodes and the bidirectional optimization strategy for path smoothing are introduced to reduce redundant nodes, which effectively makes the search space smaller and the path smoother. The simulation experiments show that, compared with the colony algorithm and Dijkstra algorithms, the proposed algorithm has significantly improved performance. Compared with the A* algorithm, the average planning time is reduced by 17.2%, the average path length is reduced by 2.05%, the average turning point is reduced by 49.4%, and the average turning Angle is reduced by 75.5%. The improved A* algorithm reduces the search space by 61.5% o... [more]

In this work, a series of vanadium-substituted phosphomolybdic acids were synthesized and tested as the catalysts for the synthesis of solketal, a green fuel bioadditive, from the condensation reaction of glycerol with acetone. The objective was to demonstrate that an easily synthesizable solid catalyst can efficiently promote glycerol condensation with acetone at room temperature. The activity of pristine heteropolyacid (i.e., H3PMo12O40) and its vanadium-substituted cesium salts (Cs3+nPMo12-nVnO40; n = 0−3) was evaluated in condensation reactions carried out at room temperature. Among the catalysts tested, Cs4PMo11VO40 was the most active and selective towards a five-member ring solketal isomer (dioxolane). A high yield of solketal (i.e., 95% conversion and 95% selectivity to solketal) was achieved in glycerol condensation with acetone at room temperature within a short reaction time (2 h). The influence of the main reaction parameters, such as the acetone−glycerol molar ratio, catal... [more]

Today’s environmental challenges, marked by escalating pollution levels, climate change and diminishing natural resources, urgently require innovative solutions, particularly in waste and wastewater management [...]

The effect of boron (B) on the microstructures and low-temperature impact toughness of medium-carbon CrMo steel quenched at 870~1050 °C and tempered at 600 °C was studied via Charpy impact testing and microstructure characterizations. The results showed that with an increasing B content from 0 to 50 ppm, the low-temperature impact toughness deteriorated significantly at quenching temperatures (Tq) lower than 950 °C but increased at a higher Tq of 1050 °C. Undissolved M2B particles remained and coarsened during the holding process due to the low Tq, decreasing the critical stress required for crack initiation and deteriorating the impact toughness accordingly. However, this detrimental effect of B could be mitigated by a higher Tq, and the favorable influences on the impact toughness improvement could be attributed to (1) the finer M2B particles formed during quenching effectively pinning the austenite grain boundaries (GBs), leading to a finer block size and a high density of high-angl... [more]

The valorization of greenhouse gases, especially when focused on carbon dioxide, currently belongs to the main challenges of pro-environmental chemical processes. One of the important technologies in this field is dry methane reforming (DMR), leading to the so-called synthesis gas (CO + H2). However, to be efficient and economically viable, an active and stable catalyst is required. Ni-based systems can be recommended in this regard. This research aimed to investigate how nickel content can influence the activity of model NiOx/CeO2 catalysts in DMR. A series of NiOx/CeO2 samples of various nickel loadings (0−10 wt.%) were prepared through dry impregnation. The obtained samples were characterized through XRD, RS, N2-BET, DRIFT, SEM, UV/Vis-DR, and XPS. Nonlinear changes in surface properties of the investigated samples with increasing nickel concentration were found. The observed changes are mirrored both in the determined nickel speciation and in the corresponding catalytic activity. T... [more]

This paper presents laboratory devices on which measurements were carried out to prove the validity of the assumption about the reduction in vibrations transmitted to the conveyor belt structure generated by the impact forces of falling material grains in the places of transfer or on the hoppers of conveyor belts. In order to limit damage to the conveyor belts caused by the impact of the sharp edges of material grains, conveyor belts are supported by impact rollers or impact rubber rods. A special modification of the fixed conveyor idler is presented, which consists of inserting plastic brackets into the structurally modified roller axle holders of the fixed conveyor idler. Measurements showed that the specially modified fixed conveyor idler resulted in a higher damping of up to 15% of the impact forces of the falling weight on the rubberized hoop of the impact roller shell compared to the conventional fixed conveyor idler design. Measurements carried out show that the effective vibrat... [more]

Most structural faults in metal parts can be attributed to fatigue crack propagation. The analysis and prognostics of fatigue crack propagation play essential roles in the health management of mechanical systems. Due to the impacts of different uncertainty factors, the crack propagation process exhibits significant randomness, which causes difficulties in fatigue life prediction. To improve prognostic accuracy, a physics-based Tweedie exponential dispersion process (TEDP) model is proposed via integrating Paris Law and the stochastic process. This TEDP model can capture both the crack growth mechanism and uncertainty. Compared with other existing models, the TEDP taking Wiener process, Gamma process, and inverse process as special cases is more general and flexible in modeling complex degradation paths. The probability density function of the model is derived based on saddle-joint approximation. The unknown parameters are calculated via maximum likelihood estimation. Then, the analytic... [more]

Investigation of breakdown pressure in wellbores in complex conditions is of great importance, both in fracture design and in wellbore log interpretation for in situ stress estimation. In this research, using a two-dimensional numerical model, the breakdown pressure is determined in ellipsoidal and breakout wellbores. To find the breakdown pressure, the mixed criterion is used, in which the toughness and the tensile strength criteria must be satisfied concurrently. In breakout boreholes, the breakdown pressure is lower than the circular wellbores; indeed, the ratio of the breakdown pressure of the breakout wellbore to the breakdown pressure in the circular wellbore is between 1 and 0.04, depending on the deviatoric stress and the width and depth of the breakout zone. In breakout wellbores, the fracture initiation position depends on the deviatoric stress. In small deviatoric stresses, the fracture initiation position is aligned with the minimum in situ stress, unlike circular boreholes... [more]

In this work, an enzyme cocktail with β-mannanase as the main activity was immobilized on epoxy resin foams filled with fibers from annatto capsules. The catalytic system was characterized by SEM, FTIR, and a mechanical crush resistance test. The behavior of the pH and temperature for the hydrolysis of the locust bean gum were also studied. With the same substrate and with respect to the free enzyme, the immobilized enzyme showed an activity retention of 79.61%. Its operational stability in ten reuse cycles did not show any statistically significant loss of activity. This catalytic system was used to study the preferential release of MOS of two to five degrees of polymerization from mannan present in dried and ground açaí seeds, which were not subjected to any other pretreatment. Using an experimental response surface design, the predicted quadratic models for the M2−M5 MOS content were obtained and they fit well with the experimental data, predicting a production range between 0.435 a... [more]

This Special Issue, titled “Sustainable Development Processes for Renewable Energy Technology II: An Overview”, presents a collection of papers in the field of sustainable development in the mineral resource sector, detailing the “seamless” process of transforming energy production into the use of renewable sources [...]

Large-scale deployment of CO2 capture, transport, and storage (CCTS) requires the rolling-out of extensive value chains. In this study, we present the development, design, techno-economic, environmental, and regulatory analysis of four pioneering chains that capture and condition CO2 from existing European industrial plants and their multi-modal transport to selected ports in Northern Europe. The pioneering chains can avoid between 65% and 87% of the industrial emissions, including scope 3, with a cost of CO2 avoided ranging between 100 and 300 euro/tCO2. The economic and environmental performance of the CCTS chains are substantially affected by the geographic location of the industrial emitters and the CO2 volumes to be transported. The analysis relies on the assumption that the four industrial plants would be early movers. While, in the future, technology maturation and infrastructure development are expected to reduce costs and emissions associated with the CCTS chain, this study q... [more]

This paper proposes an AI-assisted approach aimed at accelerating chemical process design through causal incremental reinforcement learning (CIRL) where an intelligent agent is interacting iteratively with a process simulation environment (e.g., Aspen HYSYS, DWSIM, etc.). The proposed approach is based on an incremental learnable optimizer capable of guiding multi-objective optimization towards optimal design variable configurations, depending on several factors including the problem complexity, selected RL algorithm and hyperparameters tuning. One advantage of this approach is that the agent-simulator interaction significantly reduces the vast search space of design variables, leading to an accelerated and optimized design process. This is a generic causal approach that enables the exploration of new process configurations and provides actionable insights to designers to improve not only the process design but also the design process across various applications. The approach was valid... [more]

The overarching goal of limiting the increase in global temperature to ≤ 2.0˚ C likely requires both decarbonization and defossilization efforts. Direct air capture (DAC) and CO2 electrolysis stand out as promising technologies for capturing and utilizing atmospheric CO2. In this effort, we explore the details of designing and operating an integrated DAC-electrolysis process by examining some key parameters for economic feasibility. We evaluate the gross profit and net income to find the most appropriate capacity factor, average electricity price, syngas sale price, and CO2 taxes. Additionally, we study an optimistic scenario of CO2 electrolysis and perform a sensitivity analysis of the CO2 capture price to elucidate the impact of design decisions on the economic feasibility. Our findings underscore the necessity of design improvements of the CO2 electrolysis and DAC processes to achieve reasonable capacity factor and average electricity price limits. Notably, CO2 taxes and tax credits... [more]

This paper attempts to analyze and assess Yongchuan Xiuya tea quality quickly, accurately, and digitally. The sensory evaluation method was first used to assess Yongchuan Xiuya tea quality, and then near infrared spectroscopy (NIRS) was obtained, and standard methods were applied to the testing of the chemical components. Next, principal component analysis (PCA) and the correlation coefficient method were used to comprehensively screen out the representative components. Finally, NIRS combined with partial least squares regression (PLSR) and back propagation artificial neural network (BP-ANN) methods were applied to build quality evaluation models for Yongchuan Xiuya tea, respectively, and external samples were employed to examine the practical application results of the best model. The cumulative variance contribution rate of the first three principal components of the ingredients in tea was 97.73%. Seven components closely related to tea quality were screened out, namely, amino acids,... [more]

The diffusion coefficient (D) is a key parameter that characterizes the gas transport occurring in coal seams. Typically, D is calculated using the desorption curve of particle coal. However, this method cannot accurately reflect the diffusion characteristics under the stress constraint conditions of in situ coal seams. In this study, different metamorphic deformed coals of medium and high coal rank were considered based on Fick’s law of counter diffusion. The change laws of D under different confining pressures, gas pressures, and temperature conditions were tested and analyzed, and the influencing mechanisms on D are discussed. The results showed that D of different metamorphic deformed coals exponentially decreased with an increase in confining pressures, and exponentially increased with increases in gas pressures and temperature. There is a limit diffusion coefficient. The influence of the confining pressure on D can essentially be determined by changes in the effective stress, and... [more]

Well structures with ultra-long sections have become one of the most applied technologies in the field of shale gas development. While there have been many technical challenges, enhancing the breaking efficiency and stability of polycrystalline diamond compact (PDC) bits has become an essential issue of focus. Since 2013, the well structure in the Duvernay area has been optimized multiple times, and the rate of penetration (ROP) of the entire wellbore has nearly doubled. However, there are significant differences in terms of the performances of different PDC bits, and there is still room for improvement to optimize these drill bits. For this reason, a confined compressive strength test was conducted to obtain the rock mechanical parameters from shale cores extracted from the long horizontal section. Using these data, a finite element model (FEM) was developed with a corresponding scale. A calibration of the elastic-plastic damage constitutive models was then performed using the FEM. Th... [more]

The prediction of the glass-forming ability (GFA) of metallic glasses (MGs) can accelerate the efficiency of their development. In this paper, a dataset was constructed using experimental data collected from the literature and books, and a machine learning-based predictive model was established to predict the GFA. Firstly, a classification model based on the size of the critical diameter (Dmax) was established to determine whether an alloy system could form a glass state, with an accuracy rating of 0.98. Then, regression models were established to predict the crystallization temperature (Tx), glass transition temperature (Tg), and liquidus temperature (Tl) of MGs. The R2 of the prediction model obtained in the test set was greater than 0.89, which showed that the model had good prediction accuracy. The key features used by the regression models were analyzed using variance, correlation, embedding, recursive, and exhaustive methods to select the most important features. Furthermore, to... [more]

The joints and fissures in a natural rock mass can affect the mechanical properties of the rock mass, the propagation of a blasting stress wave, and the blasting effect of the smooth surface of roadways. In the process of roadway drilling and blasting, there will inevitably be some joints between the two blast holes. Taking the joint angle as the starting point, this paper studies the rule of rock explosion crack propagation and stress variation when there are joints with different angles between two blast holes and analyzes the influence of joints on rock mechanical properties and blasting effects. The numerical simulation method and the software ANSYS/LS-DYNA are used to establish 7 rock mass models with various joint angles. When there is no joint between two holes and joints of 15°, 30°, 45°, 60°, 75°, and 90°, the propagation of explosive cracks and stress variations in the rock mass are discussed. The results show that the joints at different angles have obvious guiding and block... [more]

There is a growing interest in utilizing natural plant extracts in the food and beverage industries [...]

Wider application of BiVO4 (BVO) for photocatalytic water treatment is primarily limited by its modest photocatalytic effectiveness, despite its appropriately narrow band gap for low-cost, sunlight-facilitated water treatment processes. In this study, we have photomodified an isotype BVO, consisting of a tetragonal zircon and monoclinic scheelite phase, with Fe (Fe@BVO) and Ag (Ag@BVO) ionic precursors under UV illumination in an aqueous ethanol solution in order to assess their effect on the opto-electronic properties and effectiveness for the removal of ciprofloxacin (CIP). Fe@BVO failed to demonstrate enhanced effectiveness over pristine BVO, whereas all Ag@BVO achieved improved CIP degradation, especially 1% Ag@BVO. At pH 4 and 6, 1% Ag@BVO demonstrated nearly 24% greater removal of CIP than BVO alone. Photomodification with Fe created surface oxygen vacancies, as confirmed by XPS and Mott−Schottky analysis, which facilitated improved electron mobility, although no distinct Fe-cont... [more]

The development of sensor networks allows for easier time series data acquisition in industrial production. Due to the redundancy and rapidity of industrial time series data, accurate anomaly detection is a complex and important problem for the efficient production of the textile process. This paper proposed a semantic inference method for anomaly detection by constructing the formal specifications of anomaly data, which can effectively detect exceptions in process industrial operations. Furthermore, our method provides a semantic interpretation of exception data. Hybrid signal temporal logic (HSTL) was proposed to improve the insufficient expressive ability of signal temporal logic (STL) systems. The epistemic formal specifications of fault offline were determined, and a data-driven semantic anomaly detector (SeAD) was constructed, which can be used for online anomaly detection, helping people understand the causes and effects of anomalies. Our proposed method was applied to time-seri... [more]

This Special Issue of Processes, entitled “Synthesis, Application, and Biological Evaluation of Chemical Organic Compounds”, gathers the most recent work of leading researchers in a single forum [...]

The rock mass is susceptible to instability and damage during cavern construction. The blast-induced cracking process of the rock mass contains a wealth of information about the precursors of instability, and the identification of fracture nucleation signals is a prerequisite for effective hazard warning. A laboratory mechanical test and microseismic (MS) monitoring were carried out in the Baihetan Cavern to investigate the fracture nucleation process in the rock mass. MS monitoring shows that pre-existing microcracks were closed or new cracks were generated under the action of high stress, which caused the migration of microcracks. As the crack density increases, the fracture interaction gradually increases. The study of the rock fracture nucleation mechanism helps to reveal the MS sequences during the rock fracture process, and the fore-main shock was found in the MS sequence during access tunnel excavation. This study can effectively provide guidance for the early warning of rock ma... [more]

Shale oil reservoirs in the Daanzhai section of central Sichuan are mainly developed in the Daer subsection, with a rich resource base and great exploration and development potential. However, the shale oil reservoir is characterized by shale and limestone interactions, poor physical properties, undeveloped fractures, and large differences in the fracture pressure of interactive reservoirs. Therefore, it is necessary to use temporary plugging and diverting fracturing technology to improve the complexity of fractures in reservoir reconstruction. To this end, an experimental device was innovatively established that takes into account the morphology of fractures and the permeability of reservoirs, and it can evaluate the temporary blocks and turns within third-level fractures in a reservoir. It can simulate third-level turning fractures under conditions involving 3−15 mm crack openings and different roughness values. Using this device and method, the combination and particle-size optimiza... [more]

This article presents the technical aspects that may reduce electric power consumption during the welding of pipes with the high-frequency induction (HFI) method. Experiments were carried out at Huta Łabędy S.A. Steelworks, during the test production of 323.9 × 5.6 mm pipes of P235GH steel grade. Two sets of HFI heating system settings were studied: with a variable squeeze force of the heated edges and a variable position of the inductor in relation to the welding point. It was proven that the temperature at the welding point increased due to the stronger squeeze of the heated edges, which reduced the electric power consumption. Reducing the distance of the inductor relative to the welding point had the same effect. By optimizing the squeeze force and the position of the inductor, energy consumption was reduced by about 5.5%. Microstructural studies of the welds did not show any adverse effects of the optimization.