Metal processing may benefit from innovative lean-and-green datacentric engineering techniques. Broad process improvement opportunities in the efficient usage of materials and energy are anticipated (United Nations Sustainable Development Goals #9, 12). A CO2 laser cutting method is investigated in this study in terms of product characteristics (surface roughness (SR)) and process characteristics (energy (EC) and gas consumption (GC) as well as cutting time (CT)). The examined laser cutter controlling factors were as follows: (1) the laser power (LP), (2) the cutting speed (CS), (3) the gas pressure (GP) and, (4) the laser focus length (F). The selected 10mm-thick carbon steel (EN10025 St37-2) workpiece was arranged to have various geometric configurations so as to simulate a variety of real industrial milling demands. Non-linear saturated screening/optimization trials were planned using the Taguchi-type L9(34) orthogonal array. The resulting multivariate dataset was treated using a co... [more]

The regression model has higher requirements for the quality and balance of data to ensure the accuracy of predictions. However, there is a common problem of imbalanced distribution in real datasets, which directly affects the prediction accuracy of regression models. In order to solve the problem of data imbalance regression, considering the continuity of the target value and the correlation of the data and using the idea of optimization and confrontation, we propose an IRGAN (imbalanced regression generative adversarial network) algorithm. Considering the context information of the target data and the disappearance of the deep network gradient, we constructed a generation module and designed a composite loss function. In the early stages of training, the gap between the generated samples and the real samples is large, which easily causes the problem of non-convergence. A correction module is designed to train the internal relationship between the state and action as well as the subse... [more]

This study conducts a theoretical exploration of the free radical polymerization of polydimethylsiloxane homopolymers with a methyl methacrylate end group (PDMS-MA). To achieve this, a methodology is developed to model and simulate experimental data previously reported by one of the authors. The model incorporates a typical chain reaction mechanism, encompassing initiation, propagation, chain transfer, and termination stages. The resulting ordinary differential equations from this mechanistic approach are numerically integrated over time. Employing a semi-heuristic procedure, the study derives estimated values for the diffusive steps of termination (ktd) and propagation (kpd). Methodological accuracy is assessed through a comparison of the mathematical model results and experimental data. This evaluation includes the estimation of conversion and the average molecular weight (both number (Mn) and weight (Mw)) at three distinct monomer concentrations, considering a 4.78% mol initiator-to... [more]

A greater H/C ratio and energy demand are factors that boost natural gas conversion into electricity. The Brazilian offshore pre-salt basin has large reserves of CO2-rich associated gas. Selling this gas requires high-depth long-distance subsea pipelines, making gas-to-pipe costly; in particular, gas-to-wire instead of gas-to-pipe is more practical since it is easier to transmit electricity via long subsea distances. This research proposes and investigates an innovative low-emission gas-to-wire alternative consisting of installing supercritical direct-methane-to-methanol upstream to gas-to-wire, which is embedded in an exhaust-gas recycle loop that reduces the subsequent carbon capture costs. The process exports methanol and electricity from remote offshore oil-and-gas fields with available CO2-rich natural gas, while capturing CO2. Techno-economic, thermodynamic and lost work analyses assess the alternative. Supercritical direct-methane-to-methanol is conducted in supercritical water... [more]

In this study, the thermal transition of seaweed Saccharina latissima (raw and blanched) during drying and quality stabilization was considered in view of understanding physico-chemical changes, color changes, sorption changes and thermal property changes with respect to drying kinetics. The variations in the effective moisture diffusivity coefficient with shrinkage changes and temperature lie between 1.0 and 5.0 × 10−10 m2 s−1 (raw) and 0.5 and 3.6 × 10−10 m2 s−1 (blanched), respectively. Noticeable physical and chemical changes were observed during longer drying times, especially in the case of blanched seaweeds. At the temperature of 38.0 °C, a more yellow-colored product was obtained from raw form input materials. The blanched seaweeds accumulated moisture in a linear manner with an increase in the relative humidity of the drying air in the range of 20.0~80.0%, which resulted in high level of hysteresis between the sorption and desorption behavior. Shrinkage changes during the dryi... [more]

Centrifugal granulation technology using a spinning cup opens a potential way to recycle steel slag that is currently difficult to reuse. The objective of this research was to study the flow characteristics of a molten slag−metal mixture that was produced during smelting reduction in molten steel slag, passing over a spinning cup, so as to explore the feasibility of using centrifugal granulation technology to treat the steel slag. This was achieved by developing and implementing a computational fluid dynamics (CFD) model that incorporated free-surface multiphase flow to predict the thickness of the liquid slag film at the edge of the spinning cup (slag film thickness for short), which was an important parameter for estimating the size of the slag particles resulting from centrifugal granulation of the molten slag−metal mixture. The influences of various relevant parameters, including spinning cup diameter, slag feeding rate, cup spinning speed, etc., on the slag film thickness were ana... [more]

Biomimetic ligands are synthetic compounds that mimic the structure and binding properties of natural biological ligands. The first uses of textile dyes as pseudo-affinity ligands paved the way for the rational design and de novo synthesis of low-cost, non-toxic and highly stable triazine-scaffolded affinity ligands. A novel method to assess and enhance protein stability, employing triazine-based biomimetic ligands and using cutinase from Fusarium solani pisi as a protein model, has been previously reported. This innovative approach combined the concepts of molecular modeling and solid-phase combinatorial chemistry to design, synthesize and screen biomimetic compounds able to bind cutinase through complementary affinity-like interactions while maintaining its biological functionality. The screening of a 36-member biased combinatorial library enabled the identification of promising lead ligands. The immobilization/adsorption of cutinase onto a particular lead (ligand 3′/11) led to a not... [more]

To reduce pollution and improve the efficiency of coal resource utilization, this study proposed an integrated process for smelting reduction ironmaking and coal gasification. A multi-zone constrained mathematical model, based on heat and mass balance calculations, was developed to predict the energy and material flows required to produce 1 ton of hot metal. Two scenarios were examined: one using pure O2 as the gasification agent (referred to as the non-hydrogen-rich process) and the other using a combination of pure O2 and pure steam (referred to as the hydrogen-rich process). In the non-hydrogen rich process, as the PCR (Post Combustion Ratio) varies from 0% to 8%, the total coal consumption, O2 consumption, and volume of exported gas decrease by 57%, 57% and 53%, respectively. In the hydrogen-rich process, as the H2 content increases from 30% to 50%, the exported gas volume increases by 38%. The upper limit of H2 content in the SRV (Smelting Reduction Vessel) off-gas is mainly deter... [more]

In recent years, the Broad Learning System (BLS) has been acknowledged for its potential to revolutionize traditional artificial intelligence methods due to its short training time, strong interpretability, and simple structure. In the evolution of BLS, Prof. C. L. Philip Chen’s team introduced the Fuzzy Broad Learning System (FBLS) by replacing the feature nodes of BLS with fuzzy subsystems, thereby further reducing the training time. However, the traditional FBLS, with its straightforward structure, falls short in achieving higher fault diagnosis accuracy when handling raw vibration signals. This paper presents a bearing fault diagnosis approach employing multi-domain feature selection and the fuzzy broad learning system (MS-FBLS), aiming to enhance the diagnostic accuracy of FBLS through multi-domain feature selection. Primarily, a set of 49 features spanning time domain, frequency domain, time-frequency domain, and entropy values is extracted from the original vibrational signals.... [more]

Regarding the difficulty of extracting fault information in the faulty status of UAV (unmanned aerial vehicle) engines and the high time cost and large data requirement of the existing deep learning fault diagnosis algorithms with many training parameters, in this paper, a small-sample transfer learning fault diagnosis algorithm is proposed. First, vibration signals under the engine fault status are converted into a two-dimensional time-frequency map by multiple simultaneous squeezing S-transform (MSSST), which reduces the randomness of manually extracted features. Second, to address the problems of slow network model training and large data sample requirement, a transfer diagnosis strategy using the fine-tuned time-frequency map samples as the pre-training model of the ResNet-18 convolutional neural network is proposed. In addition, in order to improve the training effect of the network model, an agent model is introduced to optimize the hyperparameter network autonomously. Finally, e... [more]

Pool boiling heat transfer is recognized as an exceptionally effective method, widely applied across various industries. The adoption of non-azeotropic binary mixtures aligns with the environmental objectives of modern industrial development and enhances the coefficient of performance (COP) in numerous systems. Therefore, investigating the boiling heat transfer characteristics of these mixtures is crucial to improving their industrial usability. In this study, mixtures of ethylene glycol and deionized water (EG/DW) in varying concentrations were chosen as the working fluids. A comprehensive experimental setup was developed, followed by a series of experiments to assess their pool boiling performance. Simultaneously, the thermophysical parameters of these mixtures underwent detailed examination and analysis. The research revealed that the concentration of EG in the mixture markedly affects its thermal properties and temperature glide, both of which are crucial in influencing the heat tr... [more]

As a subdivision of the hydrogen energy application field, ship-borne hydrogen fuel cell systems have certain differences from vehicle or other application scenarios in terms of their structural type, safety, environmental adaptability, and test verification. The connection method of the ship-borne hydrogen storage cylinder (SHSC) is very important for the hydrogen fuel cell ship, and the structural parameters of the SHSC are particularly important in the hydrogen refueling process. To ensure the safe and reliable operation of the hydrogen-powered ship, research on the filling of the SHSC under different connection modes was carried out during refueling. In our study, a thermal flow physical model of the SHSC was established to research the hydrogen refueling process of the series and parallel SHSCs. The influence of series and parallel modes of the SHSCs on the hydrogen refueling process was explored, and the evolution law of the internal flow field, pressure, and temperature of serie... [more]

In catalysis, the design and application of supported nanoparticle catalysts is a cornerstone for addressing contemporary challenges in environmental remediation, sustainable synthesis, and analytical methodologies [...]

The rising number of natural gas purification plants has raised concerns about safety and environmental issues related to VOC (Volatile Organic Compounds) leakage. Therefore, it is crucial to conduct in-depth research on oil vapor emission patterns in these plants. Taking a typical natural gas purification plant as an example, a 1:1 scale model was established. Using methanol as the simulated medium, a study was conducted to investigate the impact of multiple leaks on the dispersion process of VOCs at the plant, combining field sampling with numerical simulation. The results indicate that wind speed influences the concentration of oil vapor, particularly on the leeward side, where vortex and reflux phenomena occur. The area of high concentration of oil vapor at v = 4 m·s−1 is eight times that at v = 8 m·s−1. Gravity and eddy currents contribute to the accumulation of oil vapor, especially closer to the central area of the plant where surrounding buildings obstruct dispersion. Smaller d... [more]

A full understanding of the fluid flow and heat transfer behaviors within a single fracture is important for geothermal heat extraction. In this study, models of single fractures with varying aperture and inner surface roughness (characterized by fractal dimension) are constructed, and a compound fracture aperture (CFA) is proposed to describe the coupled effect of fracture aperture and inner surface roughness. The effect of the fluid flow Reynolds number on heat transfer was investigated as it ranged from 4.84 to 145.63. The results show that the overall heat transfer coefficient (OHTC) in a single fracture significantly increases with the rise in fluid velocity and the compound fracture aperture. Particularly, the OHTC in a single fracture with an inner surface fractal dimension of 2.09 can be up to 1.215 times that of a parallel flat fracture when the flow velocity reaches 0.18 m/s. Moreover, for a fracture with a smaller CFA, enhancing the fracture aperture plays a decisive role in... [more]

Horizontal well cavern completion and stress release is considered a potential technique for efficient development of coalbed methane in tectonically deformed coal (TDC). Pulsating loading and unloading is a key technique for the controlled expansion of caverns and broader stress release within the reservoir. However, current understanding of the mechanical characteristics and pore network structure evolution of TDC under cyclic loading and unloading conditions is still limited. This paper employs numerical simulation methods to study the mechanical behavior and damage characteristics of TDC under cyclic loading and unloading. After obtaining a set of micromechanical parameters reflecting the behavior of TDC samples under triaxial compression in high-stress states, the effects of different stress gradients and cyclic amplitudes on the stress−strain curve, porosity changes, and crack propagation in TDC samples were analyzed. The study results indicate that under various cyclic loading a... [more]

Carbon containing waste has a certain calorific value and utilization value due to the presence of carbon elements. However, the current treatment methods are mostly traditional landfill disposal, incineration, or expensive physical and chemical reaction methods, which clearly do not comply with the rules of the current clean and resource-saving society. In this paper, a new technology and system for carbon containing wastes is proposed, which comprehensively treats and recycles carbon containing wastes, including solid waste, wastewater, waste gas, etc., using pyrolysis−gasification two-stage-cycle technology. The calculation results indicate that the technical scheme proposed in this article is feasible and can achieve the recycling of intermediate and final products, the efficient and clean utilization of carbon containing waste, and the graded utilization of energy. The clean utilization rate of carbon containing waste can be effectively improved, the energy consumption and cost of... [more]

Conventional fluid loss additives have difficultly controlling the water loss of cement−metakaolin slurry with semi-saturated brine cement slurry and limiting it to less than 50 mL (30 min)−1. This paper describes the development of an anti-salt fluid loss additive for metakaolin−cement systems. This study adopted the aqueous solution polymerization method; selected four kinds of monomers, namely 2-Acrylamido-2-methylpropane sulfonic acid (AMPS), N,N-Dimethylacrylamide (DMAA), acrylamide (AM), and methyl acrylate (MA); and performed a single-factor experiment on the proportion of monomer, reaction temperature, initiator dosage, and developed fluid loss additive, which has a high salt tolerance and temperature tolerance. This fluid loss additive can resist salt until saturation, and it can control fluid loss in 24 mL·(30 min)−1 when its dosage is 2%. The fluid loss additive can achieve the effect of fluid loss reduction by increasing the filtrate viscosity, forming a flexible elastic ad... [more]

Improving diesel engine performance requires a comprehensive understanding of fuel atomization and air−fuel mixing within the combustion chamber. Numerous studies have been conducted to reduce emissions and enhance diesel engines. However, further investigation is required on the detailed diesel spray process. In this study, we adopted extinction measurement to analyze the effects of a fuel injection pressure range of 300 to 700 bar on spray morphology. For the extinction imaging setup, we utilized a high-intensity continuous LED source along with a diffuser to ensure uniform light distribution. The high-speed extinction and image processing results indicate that increasing the injection pressure from 300 to 700 bar effectively produced a smaller particulate size (15% reduction) and a better air−fuel mixing process. Especially at the end of injection, our results show smaller liquid ligaments (50% reduction) and droplets around the injector tip with higher injection pressure cases.

Food waste, particularly animal-derived waste, presents a significant challenge globally, prompting the need for sustainable management strategies. In 2022, the amount of food waste per capita reached 131 kg/capita in the EU (European Union), which is why the search for environmentally friendly ways to manage food waste through thermochemical conversion processes has gained momentum in recent years. Animal-derived waste is a good source of organic matter (proteins, lipids, and polysaccharides) and mineral compounds (calcium phosphate, mostly hydroxyapatite). This composition makes animal-derived waste valuable for the extraction of chemical compounds, such as hydroxyapatite (HAp), which constitutes up to 70 wt% of animal bones; keratin; collagen; and hyaluronic acid (HA), to produce pharmaceutical, medical, or industrial by-products. The thermochemical conversion of chicken bones through pyrolysis and gasification creates a new opportunity to valorize this type of waste by reintroducin... [more]

Since the discovery of the vast Jimusaer shale oilfield in the southeastern Junggar Basin in 2012, there has been considerable interest in neighboring areas around Bogeda Mountain that have shale oil potential. The primary productive interval in the basin, the Middle Permian Lucaogou Formation (P2l), is well-developed in the areas of Qitai, Mulei, Shiqiantan, Chaiwopu, and Miquan. In this study, we conducted an assessment of the hydrocarbon generation potential of the P2l in these five areas and compared it with that of the P2l in the Jimusaer oilfield, which were determined by GC-MS, total organic carbon (TOC) and vitrinite reflectance (Ro) measurements, Rock-Eval pyrolysis, and organic petrology to investigate the type, origin, thermal maturity, hydrocarbon potential, and oil/gas proneness of organic matter in the P2l. Additionally, we applied open-system pyrolysis of hydrocarbon generation kinetics to explore differences in hydrocarbon generation and expulsion across various P2l mud... [more]

An experimental study and dimensional analysis of the effective heat transfer coefficient in a continuous-indirect rotatube dryer using forest biomass as the granular material isare developed in the present work. The study employed a factorial design 33 to investigate the effects of feed flow frequency (20−35−50 (Hz)), drum rotational velocity (6−8−10 (rpm)), and saturated vapor pressure (4−5−6 (bar)) on the heat transfer coefficient. During steady state conditions, the moisture content profiles and inlet and outlet temperatures were measured within the experimental region, and parameters, such as the effective heat transfer coefficient, solid retention change, and moisture content ratio were studied. The results showed that heat transfer was optimized with high solid feeding rates, low pressure, and low rotation, with solid feeding being the predominant factor. The moisture content profiles revealed a change in the hydrodynamic behavior, with the center point of the experimental regio... [more]

In July 2023, the International Maritime Organization (IMO) presented an updated strategy for decarbonizing maritime transport and achieving net-zero greenhouse gas emissions by 2050. It is therefore imperative to explore innovative solutions to achieve a blue economy and maximize energy efficiency on-board ships. For this reason, the current study aims to integrate the organic Rankine cycle (ORC) and thermoelectric generator (TEG) on board a container ship to generate electrical energy and reduce fuel consumption. The combined system will benefit from the waste heat of a marine diesel engine installed on board. The current study uses R245fa as the organic liquid and analyzes the effects of varying the evaporation pressure on the energetic and economic performance indicators by modeling the combined system in Engineering Equation Solver (EES) software. The results show that the energy efficiency of the ORC system increases from 12.3% at 3.5 bar to 17.3% at 8 bar. In comparison, the ene... [more]

Nonwoven fabrics with appropriate hydrophilicity and potent antimicrobial properties hold important promise for hygiene applications. However, existing materials with certain limitations and complex manufacturing steps, along with the unavoidable use of chemicals in the process, are limited to a certain extent in terms of the balance between comfort and antimicrobial properties. In this paper, a polyimide (PI) fiber was reported to be used for the preparation of PI composite nonwoven fabrics (5-P), which can effectively enhance the surface hydrodynamic and antimicrobial properties of the nonwoven by a one-step plasma treatment on one side. After treatment, the one-sided water contact angle (WCA) changed from 121.5° to 68.5°, and the permeation volume from 0.7 to 2.1 g, with a relative increase of 181.9%. Meanwhile, the reverse osmosis amount was only 0.5 g, achieving rapid permeation while keeping a low reverse osmosis amount. The antimicrobial experiment showed that plasma-treated 5-P... [more]

As the core power element of a centrifugal fan, the impeller’s structural parameters are important factors affecting the aerodynamic performance of the fan. Therefore, to improve the aerodynamic performance of centrifugal fans, in this study, we take the Powered Air-Purifying Respirator (PAPR) power system as the object of research and use a combination of computational fluid dynamics (CFD) and experimental validation to investigate the effects of the number of blades, blade inlet angle, blade outlet angle, blade height, and blade thickness on the aerodynamic performance of the fan. A five-factor, four-level orthogonal test table L16 (45) was selected to obtain the optimal combination of structural parameters for the impeller. In addition, in order to identify and visualize the features of the vortex, Q Criterion Normalized is applied to the simulation on the basis that the minimum pressure appears in the vortex core. In this study, Q Criterion Normalized is used to compare the interna... [more]