In order to improve the cleanliness of steel, non-aluminum deoxidation processes have begun to replace aluminum deoxidation processes. Although the aluminum deoxidation process can reduce the oxygen content in steel to <10 × 10−6, this deoxidation method causes fatigue failure resulting from the formation of large-grained spherical (Ds-type) inclusions composed of calcium−aluminate. It also tends to lead to nozzle blockage during casting. Given the above problems, this study conducted an in-depth investigation of silicon−manganese deoxidation. Thermal experiments and thermodynamic calculations were used to assess the impact of different Mn−Si ratios on the oxygen content and inclusion characteristics during the deoxidation process of molten steel with different initial oxygen contents. The experimental samples were analyzed using an oxygen−nitrogen−hydrogen analyzer, a direct reading spectrometer, and an automatic scanning electron microscope. After that, the samples were electrolyz... [more]

Accurately estimating the gas-flow rate at a wellhead to invert the formation pressure and production capacity information can be the basis for subsequent well-killing parameter design following oil and gas-well drilling blowout and ignition. Based on the multicomponent characteristics of the blowout gas and the turbulence intensity of the blowout flame, as well as the effects of complex factors such as environmental wind direction, wind speed, and wellhead structure, a numerical model for actual drilling blowout ignition is established. Jet-flame experiments are conducted under blowout conditions to verify the accuracy of the model. The temperature and radiation fields and flame morphologies of the well jet flow flame under different lateral wind speeds, well jet flow rates, and wellhead diameters are analyzed. Previous studies have found that as the lateral wind speed increases, the maximum temperature and maximum thermal radiation intensity of the blowout flame first decrease and th... [more]

During fracturing operations, special situations are often encountered. For example, the insufficient proppant-carrying capacity of fracturing fluid can cause quartz sand or ceramsite to settle near the wellbore and form a sand plug. Alternatively, excessive sand injection intensity can lead to severe accumulation of injected sand near the wellbore and also form a sand plug. These special situations are reflected in the fracturing operation curve as an abnormal increase in oil pressure over a short period of time. If not handled promptly, they can have unimaginable consequences. Sand plugs in fracturing operations, characterized by their speed and unpredictability, often form rapidly, within about 20 s. Conventional methods for on-site sand-plug warnings during fracturing include the oil pressure−time double logarithmic slope method and the net pressure−time double logarithmic slope method. Although these methods respond quickly, their warning results are unstable and vary significantl... [more]

The use of lactic acid bacteria (LAB) for the biocontrol of fungi that cause fruit and vegetable deterioration is a highly promising strategy. However, one of the main challenges lies in maintaining both viability and antifungal activity even in conditions that are unfavorable for LAB. The microencapsulation of LAB can minimize the impact of environmental conditions, helping to maintain viability, but there is still little information on what occurs with respect to antifungal activity. Therefore, the objective of this study was to evaluate the effect of microencapsulation with several polymer blends on the viability and antifungal activity of Lactiplantibacillus plantarum TEP15 and L. pentosus TEJ4. Sodium alginate (2%), sodium alginate−gum arabic (2%:1%), sodium alginate−k-carrageenan (2%:0.05%), and sodium alginate−whey protein (0.75%:1.5%) were used as encapsulating polymers. After processing (day 0), as well as after 14 and 28 days of storage, the encapsulation efficiency, moisture... [more]

The selection of entrainers primarily focuses on their ability to alter the relative volatility. However, the impact of feed composition on entrainer selection has often been overlooked. In this study, we conducted two case analyses of the minimum azeotropic mixtures in the ethyl acetate−ethanol and acetone−methanol systems to explore how the feed composition influences the entrainer selection when aiming for maximum economic efficiency. Additionally, the impact of the entrainer type (positive or reverse) on the economic benefits was also investigated. The cases revealed that economic benefits will be notably enhanced when the selected entrainer preferentially targets and removes the low-content component as the light key component. For the two cases studied, when the feed composition was 0.2−0.8, compared to preferentially separating the high-content component, preferentially separating the lower-content component resulted in a reduction in energy consumption by more than 24.14% and 2... [more]

The study of porous liquids (PLs) using molecular dynamics (MD) simulation is one of the most interesting and attractive research topics. The possibility of creating permanent porosity in a solvent and increasing its adsorption capacity is very practical. The purpose of the present study is to examine how an MD model can be developed to evaluate the possibility of PL formation. Additionally, the validation of the model was conducted by simulations using two metal−organic frameworks (MOFs) including zeolitic imidazolate framework-8 (ZIF-8) and Hong Kong University of Science and Technology-1 (HKUST-1) as porogens and water (H2O) and triethylene glycol (TEG) as solvents. The results revealed that H2O and TEG are incapable of penetrating the ZIF-8 pores due to their small size and unfavorable thermodynamics; however, both solvents easily penetrate through the large HKUST-1 pores. These observations aligned with findings from experimental literature studies, thus confirming the validity of... [more]

The subsea control system, a pivotal element of the subsea production system, plays an essential role in collecting production data and real-time operational monitoring, crucial for the consistent and stable output of offshore oil and gas fields. The increasing demand for secure offshore oil and gas extraction underscores the necessity for advanced reliability modeling and effective maintenance strategies for subsea control systems. Given the enhanced reliability of subsea equipment due to technological advancements, resulting in scarce failure data, traditional reliability modeling methods reliant on historical failure data are becoming inadequate. This paper proposes an innovative reliability modeling technique for subsea control systems that integrates a Wiener degradation model affected by random shocks and utilizes the Copula function to compute the joint reliability of components and their backups. This approach considers the unique challenges of the subsea environment and the co... [more]

Sustainable manufacturing practices are becoming increasingly necessary due to the growing concerns regarding climate change and resource scarcity. Consequently, material recycling technologies have gradually become preferred over conventional processes. This study aimed to recycle waste polylactic acid (PLA) from household-disposed cups and lids to create 3D-printed parts and promote sustainable manufacturing practices. To achieve this, the current study utilised virgin and post-consumer PLA (PC-PLA) (sourced from household waste) blends. The PC-PLA wastes were shredded and sorted by size with the aid of a washing step, resulting in a filament with a 1.70 ± 0.5 mm diameter without fragmentation or dissolution. A 50:50 wt.% blend of virgin PLA (vPLA) and PC-PLA was selected as the standard recycling percentage based on previous research and resource conservation goals. The study investigated the impact of three 3D printing parameters (layer height (LH), infill density (I), and nozzle t... [more]

The production of low-dimensional materials is the key topic of nanoscience. The development of new routes to downsize organic and inorganic materials has focused the attention of a great part of the scientific community that is still debating on the best route to pursue. Among nanostructures, 2D species have been investigated since the discovery of graphene. Nonetheless, the production of 2D materials is very complex, and the discussion on which is the most profitable way is still open. Ultrasound-assisted techniques represent one of the best routes for the production of 2D materials with minimum consumption of energy and best performances. Accordingly, we present a concise and exhaustive discussion about the use of ultrasound-assisted techniques for the production of both organic and inorganic 2D materials, also providing a theoretical overview of the mechanism behind the use of ultrasounds in synthetic material science.

Air DTH (Down-The-Hole) hammer percussion drilling (vibration percussion drilling) has proven to be a highly efficient geothermal drilling technique, and percussion fractures near the wellbore benefit geothermal energy development in many ways (such as hydraulic fracturing, perforation, etc.). However, no research has been done on the mechanism of fracture-increasing and permeation-increasing in granite pore walls by air DTH hammer percussion drilling. This article: (1) using an air drilling test device, an air DTH hammer whole bit impact rock fragmentation test was conducted on granite in an atmospheric environment; (2) dyeing experiments, CT scanning, and 3D reconstruction modeling were used to characterize and identify wellbore cracks; (3) research the strength, porosity, and permeability changes of granite wellbore through mechanical and permeability testing experiments; and (4) numerical simulation of impact stress waves using particle flow code (PFC) 6.0 software to demonstrate t... [more]

Fracture and stress environments significantly affect the flow of coalbed methane. Under stress, fracture deformation and damage occur, which change the original fracture characteristics and lead to changes in gas flow characteristics. The change in gas pressure gradient makes the fluid flow obviously nonlinear. Using linear flow theory to describe the fracture flow leads to a large error in predicting coalbed methane productivity. In this study, seepage tests on fractured coal are carried out under different stresses and gas pressure gradients, the nonlinear flow and changes in related parameters are analyzed, and the applicability of the nonlinear flow equation is evaluated. The resulting seepage of the gas flow in the fracture under stress is obviously nonlinear, which gradually increases with increasing effective stress and gas pressure gradient. When the Forchheimer equation is used to characterize the nonlinear seepage in fractures, the coefficients increase with increasing effec... [more]

The constantly growing demand for renewable electrical energy keeps the continuation of battery-related research imperative. In spite of significant progress made in the development of Na- and K-ion systems, Li-ion batteries (LIBs) still prevail in the fields of portative devices and electric or hybrid vehicles. Since the amount of lithium on our planet is significantly limited, studies dedicated to the search for and development of novel materials, which would make LIBs more efficient in terms of their specific characteristics and life lengths, are necessary. Investigations of less industry-related systems are also important, as they provide general knowledge which helps in understanding directions and strategies for the improvement of applied materials. The current paper represents a comprehensive study of cubic Li2Fe1−xCoxSeO compounds with an anti-perovskite structure. These solid solutions demonstrate both cationic and anionic electrochemical activity in lithium cells while being... [more]

At present, assessment techniques for the fracability of shale reservoirs, which rely on the formation of an effective fracture network, are scarce. Hence, in order to assess the fracability, it is critical to establish a quantitative correlation between the pattern of fracture distribution after fracture and fracability. The present investigation utilizes three-dimensional digital core technology and triaxial compression experiments to simulate the fracturing process in typical domestic shale reservoir cores. In addition to utilizing the maximum ball algorithm to extract fracture images, a number of other techniques are employed to compute the spatial quantitative parameters of the fractures, including least squares fitting, image tracking algorithms, and three-dimensional image topology algorithms. The introduction of the notion of three-dimensional fracture complexity serves to delineate the degree of successful fracture network formation subsequent to fracturing. A quantitative fra... [more]

With the notable achievements attained through the implementation of steam-assisted gravity drainage (SAGD), the vertical−horizontal steam drive (VHSD) emerges as a pivotal technological advancement aimed at significantly enhancing the efficiency of thin reservoir heavy oil recovery subsequent to steam cyclic stimulation. The inclusion of nitrogen assistance has proven effective in enhancing the efficacy of gravity drainage techniques in reservoir development. However, it is noteworthy that this method has only led to improvements in approximately 50% of the well groups within the observed field. The comprehensive evaluation index of VHSD was proposed, and as the objective function, it was determined that the greatest contribution to the VHSD technique lies in oil saturation, accounting for 40% of the overall evaluations. This differs from conventional SAGD operations, where reservoir thickness serves as the primary determinant. Building upon an enhanced physical simulation similarity... [more]

In this study, lithium was recovered from spent lithium-ion batteries through the crystallization of lithium carbonate. The influence of different process parameters on lithium carbonate precipitation was investigated. The results indicate that under the conditions of 90 °C and 400 rpm, a 2.0 mol/L sodium carbonate solution was added at a rate of 2.5 mL/min to a 2.5 mol/L lithium chloride solution, yielding lithium carbonate with a recovery rate of 85.72% and a purity of 98.19%. The stirring rate and LiCl solution concentration significantly impact the particle size of lithium carbonate aggregates. As the stirring rate increases from 200 to 800 rpm, the average particle size decreases from 168.694 μm to 115.702 μm. Conversely, an increase in the LiCl solution concentration reduces the lithium carbonate particle size, with an average particle size of only 97.535 μm being observed at a LiCl solution concentration of 2.5 mol/L. It was also observed that nickel and cobalt ions become incor... [more]

Rotating machinery fault diagnosis is of key significance for ensuring safe and efficient operation of various industrial equipment. However, under nonstationary operating conditions, the fault−induced characteristic frequencies are often time−varying. Conventional Fourier spectrum analysis is not suitable for revealing time−varying details, and nonstationary fault feature extraction methods are still in desperate need. Order spectrum can reveal the rotational−speed−related time−varying frequency components as spectral peaks in order domain, thus facilitating fault feature extraction under time−varying speed conditions. However, the speed−unrelated frequency components are still nonstationary after angular−domain resampling, thus causing wide−band features and interferences in the order spectrum. To overcome such a drawback, this work proposes a rotating machinery fault diagnosis method based on adaptive separation of time−varying components and order feature extraction. Firstly, the r... [more]

In this study, a falling weight impact test was conducted on EH690 steel specimens with V-notches using Digital Imaging Correlation (DIC). In conjunction with scanning electron microscopy (SEM), the plastic deformation and crack initiation processes were examined at the notch of the specimen under different impact energies (90 J, 120 J, 135 J and 150 J). ABAQUS was used to simulate the plastic deformation of an EH690 specimen. The results show that the strain at the notch tip experienced some elasticity and yielding as the load increased under different impact energies. The load remains unchanged or decreases slightly when a plastic hinge forms at the tip of the notch. According to the microscopic images, there are three areas on the fracture surface: a fiber area, a radiation area, and a shear lip area. With increasing deformation, a crack source forms in the middle of the V-shaped notch and propagates to the inside and outside surfaces of the sample. Cracks are primarily caused by du... [more]

In addressing the issue of climate change, the Chinese government has established a definitive objective to attain its peak carbon emissions by 2030 and strive for carbon neutrality by 2060. This effort aims to progressively achieve a state of net-zero carbon dioxide (CO2) emissions. In the given scenario, this research examines challenges in promoting low-carbon manufacturing (LCM) within the Chinese automotive sector, specifically in the context of Green Tech projects. In view of greater emphasis on environmental sustainability and technological innovation, this study aims to uncover challenges restraining the adoption of LCM in one of the world’s largest automotive markets, China. A three-step methodology was adopted by incorporating a literature review, the Delphi method, Interpretive Structural Modeling (ISM), and MICMAC analysis. In the first stage, relevant articles were selected scientifically to identify the main challenges in previous studies by following the relevant keyword... [more]

This study investigates the effectiveness of microwave treatment (MW) on the antifungal properties of Norway spruce wood and the leaching of preservatives. Given the environmental and health concerns about conventional wood preservatives, this study evaluates microwave treatment as a sustainable pretreatment to limit the leaching of preservatives from wood. In the experiment, wood samples were treated with microwaves at five different energy levels before being impregnated with copper−ethanolamine- and boron-based preservatives. We assessed preservative retention by leaching tests and assessed the resistance of the wood to fungal attack. The results show that MW treatment improves the uptake and fixation of preservatives, reduces leachability, and significantly improves the durability of an otherwise perishable wood against fungal attack. This study emphasises the potential of microwave treatment for wood preservation. It offers an environmentally friendly approach to extending the lif... [more]

Wildfire is one of the most critical natural disasters that poses a serious threat to human lives as well as ecosystems. One issue hindering a high accuracy of computer vision-based wildfire detection is the potential for water mists and clouds to be marked as wildfire smoke due to the similar appearance in images, leading to an unacceptable high false alarm rate in real-world wildfire early warning cases. This paper proposes a novel hybrid wildfire smoke detection approach by combining the multi-layer ResNet architecture with SVM to extract the smoke image dynamic and static characteristics, respectively. The ResNet model is improved via the SE attention mechanism and fully convolutional network as SE-ResNet. A fusion decision procedure is proposed for wildfire early warning. The proposed detection method was tested on open datasets and achieved an accuracy of 98.99%. The comparisons with AlexNet, VGG-16, GoogleNet, SE-ResNet-50 and SVM further illustrate the improvements.

The development of power grids is hindered by the limited transmission capacity of cable equipment, necessitating the accurate prediction of dynamic ampacity for cable expansion. This study focuses on the 110 kV cable intermediate joint, employing radial and axial inversion techniques for real-time conductor temperature inversion. Utilizing the Prophet time series model, we predict environmental changes and propose a dynamic ampacity evaluation method for cable intermediate joints. Experimental validation confirms the model’s accuracy, with prediction errors under 10 K, demonstrating its potential for enhancing cable system reliability and power grid development.

The detection of metal ions is an option for maintaining water quality and diagnosing metal ion-related diseases. In this study, we successfully detected metal ions using fluorescent peptides in water. First, we prepared seven linear (L1−L7) and seven cyclic (C1−C7) peptides containing two pyrenyl (Pyr) units and assessed the response to various metal ions by fluorescence. The results indicated that C1, which contains a hexameric cyclic peptide moiety consisting of Pyr and Gly units, did not show a fluorescent response to metal ions, while the linear L1 corresponding to C1 showed a response to Cu2+, but its selectivity was found to be poor through a competition assay for each metal ion. We then assessed C2−C7 and L2−L7, in which Gly was replaced by His units at various positions in the same manner. The results showed that C2−C7 responded to Cu2+ in a manner dependent on the His position. Additionally, superior selectivity was observed in C7 through a competition assay. These results de... [more]

CNT-NH2-Cu-BTC was prepared via hydrothermal synthesis for the adsorption and separation of CO2/CH4 mixtures with 2, 6, and 10% multiwalled carbon nanotube (MWCNT) additions. NH2-BTC composites were synthesized by changing the organic ligand and adding NH2-BDC (15, 25, 35, and 45%) to improve the adsorption capacity. MWCNTS were loaded to enhance the water stability of the material. The structure, surface morphology, and pore size distribution of the composites were characterized using X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and specific surface area and pore structure measurements. The CO2/CH4 selective adsorption performance was studied via breakthrough experiments using a self-made adsorption device. The CO2 adsorption capacity of Cu-BTC increased due to the addition of NH2-BDC, with 35%NH2-Cu-BTC exhibiting the best CO2 adsorption property, i.e., a CO2 adsorption capacity of 1.82 mmol/g and a CO2/CH4 sepa... [more]

One of the main trends in the development of the modern electronics industry is the miniaturization of electronic devices and components. Miniature electronic devices require compact cooling systems that can dissipate large amounts of heat in a small space. Researchers are exploring ways to improve the design of the heat sink of the cooling system in such a way that it increases the heat flow while at the same time reducing the size of the heat sink. Researchers have previously proposed different designs for heat sinks with altered fin shapes, perforations, and configurations. However, this approach to optimizing the design of the heat sink results in an increase in the labor intensity of its production. Our goal is to optimize the heat sink design to reduce its size, reduce metal consumption, and increase heat flow. This goal is achieved by changing the number of fins and the distance between them. In this case, there is no significant difference in the geometry of a conventional plat... [more]

New energy storage methods based on electrochemistry can not only participate in peak shaving of the power grid but also provide inertia and emergency power support. It is necessary to analyze the planning problem of energy storage from multiple application scenarios, such as peak shaving and emergency frequency regulation. This article proposes an energy storage capacity configuration planning method that considers both peak shaving and emergency frequency regulation scenarios. A frequency response model based on emergency frequency regulation combined with low-frequency load shedding is established, taking into account the frequency safety constraints of the system and the principle of idle time reuse, to establish a bi-level programming model. In the upper-level model, the optimization objective is to minimize the annual operating cost of the system during the planning period, combined with the constraints of power grid operation to plan the energy storage capacity. The lower-level... [more]