(1) Purpose: The aim of the study was to develop a nanocomposite with copper nanoparticles constituting a bacteriostatic surface to maintain human lung cell function. (2) Methods: A polyelectrolyte layer coating that incorporated copper nanoparticles was designed. As a bacteriostatic factor, copper nanoparticles were applied as a colloidal solution of copper nanoparticles (ColloidCuNPs) and a solution of copper nanoparticles (CuNPs). The influence of the polyelectrolytes on selected Gram (+) and Gram (−) strains was examined. The function and morphology of the human adenocarcinoma A549 cell line, comprising human epithelial lung cells cultured in the presence of nanocomposite layer coatings, were evaluated. We applied fluorescence and scanning electron microscopies, as well as flow cytometry, for these studies. Furthermore, the layer coating material was characterized by atomic force microscopy (AFM) and energy dispersive X-ray analysis (EDX). (3) Results: It was observed that the poly... [more]

is a well-recognized sugar-cane-derived product with a sweet, characteristic flavor and hard texture. This product is a cultural Brazilian landmark, particularly in Ceará, Brazil, where it is usually produced by small family businesses and consumed locally. This feature contributes to the difficulties of rapadura production standardization, a requirement for the global market. Against this backdrop, this study focuses on analyzing the centesimal composition and mineral content of rapadura. Six samples from different cities in Ceará were analyzed for moisture, ash, lipids, proteins, carbohydrates, energy value, and minerals. The results ranged from 6.42−11.74% for moisture, 0.23−1.12% for ash, 0.49−0.92% for protein, 85.18−89.12% for lipids, and 352.00−391.19 Kcal for energy value. Significant variations were observed between the samples, showing a lack of standardization in the production process. The analysis of micronutrients revealed low levels, with copper and iron standing out in... [more]

The aeronautical sector faces challenges in meeting its net-zero ambition by 2050. To achieve this target, much effort has been devoted to exploring sustainable aviation fuels (SAF). Accordingly, we evaluated the technical performance of potential SAF production in an integrated first- and second-generation sugarcane biorefinery focusing on Brazil. The CO2 equivalent and the renewability exergy indexes were used to assess environmental performance and impact throughout the supply chain. In addition, exergy efficiency (ηB) and average unitary exergy costs (AUEC) were used as complementary metrics to carry out a multi-criteria approach to determine the overall performance of the biorefinery pathways. The production capacity assumed for this analysis covers 10% of the fuel demand in 2020 at the international Brazilian airports of São Paulo and Rio de Janeiro, leading to a base capacity of 210 kt jet fuel/y. The process design includes sugarcane bagasse and straw as the feedstock of the bi... [more]

In this paper, the local corrosion inhibition effect of imidazoline on N80 oil pipeline steel in a NaCl-Na2S solution was studied by the simulated blocking tank cell method, and the corrosion processes of the cathode and anode in the blocking zone were simulated. The blocking corrosion behavior of the pipeline tubing steel N80 in simulated corrosion solutions without and with different concentrations of an imidazoline corrosion inhibitor was studied by chemical analysis and electrochemical analysis. The results show that in the three solution systems, after the anode polarization of the occluded cell, the solution in the occluded region is acidified, the pH value decreases sharply, the migration of Cl− and S2− increases, and the concentration is increased in the blocked area. After adding the imidazoline corrosion inhibitor, the imidazoline inhibitor can reduce the migration of small-radius anions (Cl− and S2−) to the occluded area, inhibit the acidification of the solution in the occl... [more]

Microdroplets have been widely used in different fields due to their unique properties, such as compartmentalization, single-molecule sensitivity, chemical and biological compatibility, and high throughput. Compared to intricate and labor-intensive microfluidic techniques, the centrifuge-based method is more convenient and cost-effective for generating droplets. In this study, we developed a handy injection molding based method to readily produce monodisperse droplets by centrifugation. Briefly, we used two three-dimensional (3D) printed master molds with internal cavities to forge two coupled sub-molds by injecting polydimethylsiloxane (PDMS) and casted these two PDMS sub-molds into a nested structure that clamps the micro-channel array (MiCA) by injecting polyurethane resin. This method enables the generation of various sizes of monodispersed microdroplets by centrifugation with proper parameters within 10 min. To assess the performance of this method, homogeneous fluorescent hydroge... [more]

It is generally accepted that organic−inorganic interactions involving H-rich fluids (i.e., H2O and H2) contribute significantly to hydrocarbon (HC) generation in sedimentary basins. However, the effects of two hydrogenation processes involving H2O and H2 on the generation and C/H isotope fractionation of HC gases from organic matter (OM) remain unclear. In this study, two groups of hydrothermal experiments involving low-mature kerogen without (Group 1) and with FeS (Group 2) at 330−420 °C and 50 MPa were conducted to simulate the hydrogenation of OM by H2O and H2, respectively. The experimental results show that the redox reactions between H2O and FeS lead to the generation of considerable amounts of H2 in the Group 2 experiments. HC gas yield in the Group 2 experiments reaches 1.8−3.6 times that in the Group 1 experiments at Easy%Ro of 1.05−2.50%. In addition, indirect hydrogenation via H2O-derived H2 generates HC gases with smaller 13C fractionation and more negative δ2H compared wi... [more]

In the original publication [...]

This article summarises the possibility of replacing the coke breeze sintering fuel with an economically and ecologically more suitable fuel, anthracite. The main focus is on the possibility of replacing coke breeze with anthracite, during which, the replacement process is accelerated and the other properties are also affected. The analyses performed showed that the replacement of coke breeze with different amounts of anthracite does not have a negative effect if the initial permeability of the sintering bed is the same.

The use of an open-graded friction course (OGFC) as a road surface demonstrates significant advantages in reducing driving noise and improving road drainage and safety. This study aims to enhance the overall performance of OGFC-13 by incorporating double-adding fiber technology. Laboratory tests were conducted on six OGFC-13 mixes modified with varying fiber ratios of lignin fibers (LFs) and glass fibers (GFs). Both GF and LF significantly improved high-temperature performance, with dynamic stability values increasing proportionally to GF content. The LF:GF = 0.15:0.15 ratio achieved peak shearing strength, demonstrating better improvement over single-fiber modification. Furthermore, both fibers effectively enhanced resistance to cracking, with GF-reinforced specimens excelling in bending stress and LF-reinforced specimens demonstrating the highest flexural strain. Water stability evaluations highlighted the substantial positive impact of LF and GF, with simultaneous addition resulting... [more]

This study examined the convective drying of red cabbage at temperatures ranging from 50 to 90 °C. Mathematical modeling was used to describe isotherms, drying kinetics and rehydration process. The effects of drying conditions on energy consumption and microstructure were also evaluated. The Halsey model had the best fit to the isotherm data and the equilibrium moisture was determined to be 0.0672, 0.0490, 0 0.0379, 0.0324 and 0.0279 g water/g d.m. at 50, 60, 70, 80 and 90 °C, respectively. Drying kinetics were described most accurately by the Midilli and Kuçuk model. Also, the diffusion coefficient values increased with drying temperature. Lower energy consumption was found for drying at 90 °C and the rehydration process was best described by the Weibull model. Samples dehydrated at 90 °C showed high water holding capacity and better maintenance of microstructure. These results could be used to foster a sustainable drying process for red cabbage.

The flow field structure and pressure pulsation characteristics in two series of trailing edges of a centrifugal pump are investigated using the SST k-w turbulence model. Series 1 involves varying the impeller exit angle, and Series 2 involves varying the impeller exit shape. The entropy generation rate analysis method is used to evaluate the numerical simulation results. Vortex cores within the flow field are identified by applying the Ω criterion. The influence of different trailing edge configurations on the energy loss characteristics of the pumps is explored. The dynamic mode decomposition (DMD) method is used to analyze pressure pulsations at the volute considering unsteady flows in centrifugal pumps with different trailing edge shapes. The findings suggest that different trailing edge shapes can be used to adjust the energy loss proportions in various components of the pump. In Series 1, the efficiency remains nearly constant with changes in the outlet angle on both sides of the... [more]

Compared with isolated converters, transformerless converters are a preferred choice in low-voltage grids due to their efficiency and lower cost. However, leakage current and common mode (CM) voltage appear through the converter and ground in hybrid grids, which consist of AC and DC subgrids. The leakage current and CM voltage seriously influence operation and power quality in low-voltage distribution systems. This paper proposes a common-ground-type (CGT) converter equipped with a CM decoupling control strategy to eliminate the leakage current and CM voltage. A CM model is derived, and the leakage current and CM voltage are analyzed in detail. A CGT four-leg converter is constructed to eliminate the high frequency CM voltage. A dual DQ current control loop is developed to suppress the DC double-frequency ripple. Additionally, an active damping method is proposed, based on the neutral current feed-forward plus inductor current feedback, to attenuate the low frequency CM voltage. The pr... [more]

The production of high-quality castings without foundry defects at minimal production costs is a constant priority for foundries. Innovation and optimization of production processes are key to achieving this goal. Computer simulation of foundry processes offers a modern alternative to expensive and time-consuming experiments in real foundries and provides a reliable representation and analysis of casting and solidification processes. A detailed analysis of the casting and solidification simulation results allows the prediction of various risks that can cause defects in cast castings, thereby reducing their quality and, last but not least, the cost of their production. This paper deals with the analysis of a computer simulation of the casting of a brake disc in a Slovak foundry. This brake disc has had shrinkages and micro shrinkages that reduce the internal quality of the casting. These defects occurred in the ribs in the upper part of the casting under the feeders. A computer simulati... [more]

Thermal deformation of the rotor is a critical factor leading to radial air leakage in rotary air preheaters. However, previous studies have not comprehensively established the correlation between rotor thermal deformation during thermal operation and radial air leakage. This study addresses this gap by introducing a novel model for calculating radial air leakage, incorporating the thermal deformation of the rotor. To achieve this, we selected a three-section rotary air preheater from a 330 MW coal-fired unit boiler for investigation. This research begins by constructing a heat transfer−structure coupled numerical simulation model using Fluent and ANSYS Workbench. This model is employed to analyze the thermal deformation of the rotor under varying unit power generation loads. This paper meticulously examines the thermal deformation patterns of the rotor in diverse circumstances, explores their impact on air leakages, and provides a comprehensive analysis of air leakage fluctuations in... [more]

One major challenge in fluid power is the improvement and optimization of the efficiency of mobile hydraulic systems. Conventional fluid power systems often exhibit relatively low overall efficiencies caused by inefficiencies in the various components, such as a prime mover, variable displacement pump, valves, fittings, hoses, and actuators. While each component contributes to the losses in the overall system, the pump converts the mechanical shaft energy from the prime mover to energy transmitted hydraulically and is one of the most crucial components impacting overall system efficiency. Using on/off technologies, new pump architectures have enabled the opportunity to increase the efficiency over conventional designs using positive sealing valves in place of conventional port plate designs. This work proposes, investigates, and assesses the development and optimization of a digital variable displacement pump using a novel cam actuation technique on radial piston pumps. The novelty of... [more]

In the development of the Qianshao (QS) gas condensate reservoir, it is crucial to consider the phenomenon of retrograde condensation. Understanding the condensate saturation distribution with respect to time and space within the reservoir is essential for planning and implementing effective strategies for the future development of the QS gas condensate reservoir. In this paper, various PVT experiments (including reservoir oil recombination, flash separation, constant composition expansion, and constant volume depletion) were conducted to study the PVT properties and phase behavior of QS gas condensate fluid. Based on experimental data, our in-house PVT computation package was used to determine the appropriate EOS model parameters for the QS gas condensate. A four-step reservoir fluid characterization procedure and workflow for gas condensate reservoirs was developed. Furthermore, by analyzing the pressure-temperature phase envelope, the maximum possible condensate saturation in the QS... [more]

Objectives: This article investigates the corrosion behavior and mechanical-property changes of S135, G105, and V150 drill pipe materials in a high-temperature-resistant, potassium amino poly-sulfonate drilling fluid, which has good lubrication performance and contains CO2/H2S, by applying an 80% yield-limit-load simulation. The results show that the CO2-corrosion behavior of G105, S135, and V150 drill pipes are obvious under the simulated constant-load-stress-corrosion environments at the wellhead, well-middle, and bottomhole positions. Compared to uncorroded drill pipes, S135 and V150 drill pipes have increased strength and yield ratios, decreased fracture elongation, and increased sensitivity to hydrogen embrittlement under H2S action, and V150 has a greater risk of stress-hydrogen embrittlement. The strength and yield ratios of G105-material drill pipes decrease, while the fracture elongation increases; the intensity-change amplitude levels are ranked V150 > G105 > S135, and the fr... [more]

Fossil fuel extraction and utilization are associated with several environmental issues. This study examined how altering the blending proportions of mixed diesel/biodiesel/n-butanol fuels impacts combustion. Additionally, it delved into the functioning of diesel engines when utilizing these blended fuels as well as conventional diesel. A three-dimensional fluid dynamics simulation was constructed and corroborated against test outcomes obtained at 25%, 50%, 75%, and 100% loads. The findings indicated that the n-butanol addition enhanced the indicated thermal efficiency. At a 100% load, D70B30 (70% diesel + 30% biodiesel), D70B25BU5 (70% diesel + 25% biodiesel + 5%N-butanol), D70B20BU10, and D70B10BU20 exhibited 4.76%, 5.75%, 6.79%, and 8.71% higher indicated thermal efficiency values than D100 (100% diesel), respectively. The introduction of butanol enhanced the combustion environment within the combustion chamber. Compared with pure diesel, all blended fuels reduced hydrocarbon and ca... [more]

This study assessed the application of whole lipolytic cells in the pretreatment of slaughterhouse wastewater to reduce its lipid content. The fungal biomass of Rhizopus oryzae was evaluated in the hydrolysis of slaughterhouse wastewater containing high lipid concentrations, focusing on the biomass’s concentration and the effect of using an emulsifier and surfactant. The use of the whole-cells lipase of Rhizopus oryzae grown in a residual vegetable oil medium proved effective in the hydrolysis of slaughterhouse wastewater, generating concentrations of free fatty acids (FFA) ranging from 40.36 to 90.14 mM. The action of lipase in the hydrolysis of slaughterhouse residues indicated its effectiveness in pretreating lipid-rich liquid residues, potentially boosting the microbiota of this anaerobic treatment. The results showed that lipase activity without surfactant exhibited a similar performance to that of Triton X-100 in the hydrolysis of liquid residues. However, the combination of lipa... [more]

This article presents an adaptive neural network (ANN) control scheme based on a disturbance observer that can achieve trajectory tracking control of robotic manipulators under external disturbances and dynamic model uncertainties. Firstly, an ANN controller based on full-state feedback is derived using the backstepping technique to achieve an online approximation of uncertainty. The integral sliding mode surface with a position error is introduced into the controller, which reduces the steady-state error of the system and enhances robustness. Then, a novel disturbance observer is designed to estimate both the approximation errors of the ANN and external disturbances, and to provide compensation for the controller, effectively suppressing the trajectory tracking errors caused by approximation errors and disturbances. Subsequently, the Lyapunov stability theory is utilized to demonstrate the stability of the developed control strategy and the boundedness of all closed-loop signals. Fina... [more]

A combined dispersed liquid−liquid microextraction (DLLME) and chromatography (GC) method was developed for the determination of 24 aromatic substances in rosemary hydrosol in this work. The pretreatment method of DLLME was optimized by carefully selecting the appropriate extraction agents, dispersants, and their respective amounts. With carbon tetrachloride as the extractant and acetone as the dispersant, the enrichment factor of DLLME is 13.3, and the 24 target substances such as eucalyptol, camphor and verbenone can be separated within 31 min and quantified by an external standard method using gas chromatography (GC). The correlation coefficient r2 of the linear regression equation is within the range of 0.9983 to 0.9991. The detection limit of the method was 0.02 mg/L, the recovery rate of the spiked solution was 76.4−118.4%, the relative standard deviation was 0.4−6.9% and the method was used to detect the semi-finished products of rosemary hydrosol and the finished rosemary hydro... [more]

Sugarcane bagasse (SB) is a widely available agro-industrial waste residue in China that has the potential to be converted into a cost-effective and renewable adsorbent. In this study, activated carbon (AC) was prepared from SB by microwave vacuum pyrolysis using H3PO4 as the activator. To enhance the sorption selectivity and yield, the pyrolysis process of SB-activated carbon (SBAC) should be well-designed. Central composite design was employed as an optimized experiment design, and response surface methodology was used to optimize the process parameters for maximized SBAC yield and its iodine number. The results showed that the optimized parameters obtained for the SBAC are 2.47 for the impregnation ratio (IR), 479.07 W for microwave power (MP), 23.86 mm for biomass bed depth, and 12.96 min for irradiation time, with responses of 868.7 mg/g iodine number and 43.88% yield. The anticipated outcomes were substantiated, revealing a marginal 5.4% variance in yield and a mere 1.9% discrepa... [more]

Temperature is a key factor affecting the insulation performance and operation safety of cable joints. Accurate acquisition of hot spot temperatures of cable joints is a difficult issue in cable operation and maintenance. Three-core cables may have unbalanced three-phase loads in actual operation. This paper takes a 10 kV three-core cable joint as the research object; based on the temperature field numerical simulation method, it analyzes the diffusion path of the main heat flow inside the joint and establishes an inversion model that fits the hot spot temperature of the joint through the surface temperature of the cable body. At the same time, considering the special situation of the unbalanced three-phase load of a three-core cable, the joint hot spot temperature inversion model of a three-core cable under an unbalanced three-phase load is further established. This paper further uses the cable joint multi-step unbalanced load temperature rise test to verify the accuracy of the cable... [more]

Batch processing is a widely utilized technique in the manufacturing of high-value products. Traditional methods for quality assessment in batch processes often lead to productivity and yield losses because of offline measurement of quality variables. The use of soft sensors enhances product quality and increases production efficiency. However, due to the uneven batch data, the variation in processing times presents a significant challenge for building effective soft sensor models. Moreover, sensor failures, exacerbated by the manufacturing environment, complicate the accurate modeling of process variables. Existing soft sensor approaches inadequately address sensor malfunctions, resulting in significant prediction inaccuracies. This study proposes a fault-tolerant soft sensor algorithm that integrates two Long Short-Term Memory (LSTM) networks. The algorithm focuses on modeling process variables and compensating for sensor failures using historical batch quality data. It introduces a... [more]

Hard materials have found extensive applications in the fields of electronics, optics, and semiconductors. Parallel grinding is a common method for fabricating high-quality surfaces on hard materials with high efficiency. However, the surface generation mechanism has not been fully understood, resulting in a lack of an optimization approach for parallel grinding. In this study, the surface profile formation processes were analyzed under different grinding conditions. Then, a novel method was proposed to improve surface finish in parallel grinding, and grinding experiments were carried out to validate the proposed approach. It was found that the denominator (b) of the simplest form of the rotational speed ratio of the grinding wheel to the workpiece has a great influence on surface generation. The surface finish can be optimized without sacrificing the machining efficiency by slightly adjusting the rotational speeds of the wheel or the workpiece to make the value of b close to the ratio... [more]