The Occupational Health and Safety system enforces the continual improvement culture in industries for much safer processes and zero injuries. The Quality Management System also enforces the same philosophy of continual improvement within the processing system for zero defects, hence a high productivity rate. Good quality products always result from good Overall Equipment Effectiveness; hence, Process Re-Engineering is essential for the good functioning of machinery. This research is based on Integrated Management System requirements in terms of problem-solving, especially the opportunities that arise within Quality nonconformances, Safety Incidents, as well as Process Engineering related breakdowns. This study aims to develop a troubleshooting system that evaluates continual improvement projects. The method used to develop the troubleshooting system is based on Total Quality Management, where lean principles are combined with kaizen concepts and quality standards. The proposed trouble... [more]

Longitudinal cutting is the most common process in steel structure manufacturing, and the man-hours of the process provide an important basis for enterprises to generate production schedules. However, currently, the man-hours in factories are mainly estimated by experts, and the accuracy of this method is relatively low. In this study, we propose a system that predicts man-hours with history data in the manufacturing process and that can be applied in practical structural steel fabrication. The system addresses the data inconsistency problem by one-hot encoding and data normalization techniques, Pearson correlation coefficient for feature selection, and the Random Forest Regression (RFR) for prediction. Compared with the other three Machine-Learning (ML) algorithms, the Random Forest algorithm has the best performance. The results demonstrate that the proposed system outperforms the conventional approach and has better forecast accuracy so it is suitable for man-hours prediction.

The dim lighting and excessive dust in underground mines often result in uneven illumination, blurriness, and loss of detail in surveillance images, which hinders subsequent intelligent image recognition. To address the limitations of the existing image enhancement algorithms in terms of generalization and accuracy, this paper proposes an unsupervised method for enhancing mine images in the hue−saturation−value (HSV) color space. Inspired by the HSV color space, the method first converts RGB images to the HSV space and integrates Retinex theory into the brightness (V channel). Additionally, a random perturbation technique is designed for the brightness. Within the same scene, a U-Net-based reflectance estimation network is constructed by enforcing consistency between the original reflectance and the perturbed reflectance, incorporating ResNeSt blocks and a multi-scale channel pixel attention module to improve accuracy. Finally, an enhanced image is obtained by recombining the original... [more]

This research explores fluid flow speed behavior in capillary channels using additive manufacturing, focusing on stereolithography (SLA). It aims to validate microchannels fabricated through SLA for desired fluid flow characteristics, particularly capillary-driven flow. The methodology involves designing, fabricating, and characterizing microchannels via SLA, with improvements such as an air-cleaning step facilitating the production of microchannels ranging from 300 to 1000 μm. Experimental validation assesses fluid flow speed behavior across channels of varying dimensions, evaluating the impact of channel geometry, surface roughness, and manufacturing parameters. The findings affirm the feasibility and efficacy of SLA in producing microchannels with consistent and predictable fluid flow behavior between 300 to 800 μm. This study contributes insights into microfluidic device fabrication techniques and enhances the understanding of fluid dynamics in capillary-driven systems. Overall, it... [more]

The rapid expansion of the scale of wind power has led to a wave of efforts to decommission wind turbine blades. The pyrolysis of decommissioned wind turbine blades (DWTBs) is a promising technological solution. Microwave pyrolysis offers the benefits of fast heating rates and uniform heat transfer, making it a widely used method in various heating applications. However, there are few studies on the microwave pyrolysis of DWTBs, and pyrolysis characteristics under different boundary conditions remain unclear. In this paper, we investigate the pyrolysis characteristics of DWTBs by utilizing silicon carbide (SiC) particles as a microwave absorbent. The results demonstrated that, when the microwave heating power increased from 400 W to 600 W, the heating rate and pyrolysis final temperature of the material increased, resulting in a reduction in pyrolysis residual solid yield from 88.30% to 84.40%. At 600 W, pyrolysis gas components included C2H4, CH4, and CO, while the tar components incl... [more]

The Acosta method involves rewiring the yeast metabolic pathway to enhance biomass production and prevent a significant increase in higher alcohols during the late stages of fermentation. This study aimed to assess fermentation conditions to achieve Cuban schnapps with reduced concentrations of higher alcohols and replicate the process on an industrial scale. To achieve this, the quality of final sugarcane molasses for fermentation by Saccharomyces cerevisiae (S. cerevisiae) yeast was evaluated. Industrial pre-fermentation and fermentation processes were successfully conducted, followed by laboratory-scale fermentation using the Acosta fermentation method to determine crucial parameters for industrial implementation. Operational parameters for fermentation were identified from the following results: 13.5 °Brix seeding, metabolic pathway inversion of S. cerevisiae at 16 h, and an air concentration of 0.1 m3/min. The resulting Cuban schnapps obtained using this method exhibited a concent... [more]

Predicting carbon emissions is important in various sectors, including environmental management, economic planning, and energy policy. Traditional forecasting models typically require extensive training data to achieve high accuracy. However, carbon emission data are usually available on an annual basis, which is insufficient for effectively training conventional forecasting models. To address this challenge, this paper introduces an innovative carbon emissions prediction model that integrates Fibonacci attenuation particle swarm optimization (FAPSO) with the gated recurrent unit (GRU). The FAPSO algorithm is used to optimize the hyperparameters of the GRU, thereby alleviating the decline in prediction accuracy that conventional recurrent neural networks often face when dealing with limited training data. To evaluate the effectiveness of the FAPSO-GRU model, we tested it using carbon emission data from Hainan Province. Compared to the conventional GRU model, the FAPSO-GRU model achieve... [more]

The additive manufacturing (AM) field is rapidly expanding, attracting significant scientific attention. This family of processes will be widely used in the evolution of Industry 4.0, particularly in the production of customized components. However, as the complexity and variability of additive manufacturing processes increase, there is an increasing need for advanced techniques to ensure quality control, optimize performance, and reduce production costs. Multiple tests are required to optimize processing variables for specific equipment and processes, to achieve optimum processing conditions. The application of digital twins (DTs) has significantly enhanced the field of additive manufacturing. A digital twin, abbreviated as DT, refers to a computer-generated model that accurately depicts a real-world object, system, or process. A DT comprises the complete additive manufacturing process, from the initial conception phase to the final manufacturing phase. It enables the manufacturing pr... [more]

The stress and fatigue of the runner during the operation of the large Kaplan turbine are one of the key issues in the operation of turbines. Due to the complexity of the working load and the geometric configuration of the Kaplan turbine runner, the different contact modes between the internal components of the runner will have an impact on the stress and fatigue results. Therefore, the unsteady CFD calculation of the full channel is conducted in this article to analyze the hydraulic characteristics of the turbine blades in the unsteady flow field, such as pressure and torque. The pressure load is loaded onto the runner using a fluid−structure interaction (FSI) theory, and the stress characteristics of the blade, blade lever, and runner body are compared under three contact modes. Based on the dynamic stress spectrum of the blade lever calculated under three contact conditions, the life of the blade lever is predicted using the rain flow counting method and the Palmgren−Miner theory. T... [more]

This study aimed to investigate the effect of exogenous nanoparticles on the rheological properties of artificial saliva. There are four reasons for undertaking this type of research: Firstly, the number of solid particles of various origins present in the air is still high. Secondly, nanoparticles (including silver and gold nanoparticles) are increasingly used in food packaging and can migrate into food. Thirdly, saliva is the first biological fluid that comes into contact with exogenous particles. Finally, the function of saliva is also closely related to its rheological properties. Due to the remarkable properties of nano-objects, nanoparticles of various origins in the body may cause effects that have not been realised until now. Therefore, each type of nanoparticle must be tested in terms of its impact on the body/body fluid. We used silver and gold nanoparticles because they are used in the food industry, and diesel exhaust particles because they are standard components of air po... [more]

The interest in combined heat and solar power (CHP) systems has increased due to the growing demand for sustainable energy with low carbon emissions. An effective technical solution to address this requirement is using a parabolic trough solar collector (PTC) in conjunction with a Rankine cycle (RC) heat engine. The solar-powered Rankine cycle (SPRC) system is a renewable energy technology that can be relied upon for its high efficiency and produces clean energy output. This study describes developing a SPRC system specifically for electricity generation in Aden, Yemen. The system comprises parabolic trough collectors, a thermal storage tank, and a Rankine cycle. A 4E analysis of this system was theoretically investigated, and the effects of various design conditions, namely the boiler’s pinch point temperature and steam extraction from the high-pressure turbine, steam extraction from the intermediate-pressure turbine, and condenser temperature, were studied. Numerical simulations show... [more]

With the continuous deepening of oil and gas exploration and development, unconventional oil and gas resources, represented by tight oil, have become research hotspots. However, few studies have investigated tight oil potential in any systematic way in the shell limestone reservoir of the Sichuan Basin. Herein, we used thin section analysis, X-ray diffraction (XRD), high-pressure mercury intrusion, low-pressure N2 and CO2 adsorption experiments, low-field nuclear magnetic resonance (NMR), focused ion beam−scanning electron microscopy (FIB-SEM), and nano-CT to characterize multi-porous media. The reservoir space controlled by nonfabric, shell, and matrix constitutes all the reservoir space for tight oil. The interconnected porosity was mainly distributed in the range of 1% to 5% (avg. 2.12%). The effective interconnected porosity mainly ranged from 0.5% to 2.0% (avg. 1.59%). The porosity of large fractures was 0.1% to 0.5% (avg. 0.21%). The porosity of isolated pores and bound oil−water... [more]

Severe blockages of tunnel drainage systems greatly affect the lining structure of the tunnels, thus jeopardizing their stability and safety. In order to study the blockages of tunnel drainage pipes, the flow rate of a calcium carbonate crystal tunnel was measured in the mountainous area of Southwest China. According to the actual flow velocity results, numerical simulation was combined with finite element software (ANSYS Fluent). This analyzed the calcium carbonate crystallization near the interface of the tunnel drainage pipe. The results are as follows: (1) for both the Y-shaped three-way pipe and the T-shaped pipe, the values of maximum water velocity are similar but occur at different locations. At the interface of the transverse drainage pipes, flow velocity is the highest; (2) at the three-way joint segment, the water that flows in the longitudinal drainage blind tube is influenced by the water coming from the annular drainage blind tube. At the interface of the transverse drain... [more]

Renewable energy sources are increasingly integrated into power systems, leading to significant variability in operations. This necessitates robust methods for assessing operational reliability. We propose a novel model−data hybrid approach that incorporates endogenous uncertainty into the reliability evaluation process. First, unlike traditional methods that treat uncertainties as external factors, this approach recognizes that operational decisions can significantly influence how uncertainties are resolved and impact reliability metrics. The proposed method integrates device reliability indices with operational decision variables. This allows us to evaluate the impact of endogenous uncertainty on operational reliability through a reliability-constrained stochastic unit commitment model. Additionally, a model−data hybrid algorithm is introduced for efficient solution of the formulated optimization problem. Case studies demonstrate the effectiveness of the proposed method. Results also... [more]

Ester 2 was produced by reacting thiourea derivative 1 with ethyl 2-chloro-3-oxobutanoate in MeOH containing piperidine. Hydrazide 3 was produced by reacting the latter ester with hydrazine hydrate in EtOH at reflux. By reacting hydrazide 3 with aromatic/heterocyclic aldehydes, twelve derivatives of hydrazide hydrazone 5a−l were produced. Spectral measurements and elemental analysis verified the molecular structure. Compounds 2, 5a, 5c, 5d, and 5f had strong effects on all the pathogenic bacterial strains according to an evaluation of the antimicrobial qualities of the synthetic compounds. With inhibitory zone diameters ranging from 16 to 20.4 mm, hydrazide hydrazone 5f exhibited the strongest activity. Additionally, the minimum inhibitory concentration (MIC) was assessed. The best outcomes were found with hydrazones 5c and 5f. For B. subtilis, the MIC of 5c was 2.5 mg/mL. For E. coli and K. pneumoniae, the MIC of 5f was 2.5 mg/mL. The molecular mechanics-generalized born surface area... [more]

In additive manufacturing, such as Selective Laser Melting (SLM), identifying fabrication defects poses a significant challenge. Existing identification algorithms often struggle to meet the precision requirements for defect detection. To accurately identify small-scale defects in SLM, this paper proposes a deep learning model based on the original YOLOv5 network architecture for enhanced defect identification. Specifically, we integrate a small target identification layer into the network to improve the recognition of minute anomalies like keyholes. Additionally, a similarity attention module (SimAM) is introduced to enhance the model’s sensitivity to channel and spatial features, facilitating the identification of dense target regions. Furthermore, the SPD-Conv module is employed to reduce information loss within the network and enhance the model’s identification rate. During the testing phase, a set of sample photos is randomly selected to evaluate the efficacy of the proposed model... [more]

The bubbling flow plays a key role in gas−liquid−solid fluidized beds. To understand the intrinsic fluidization behaviors at the discrete bubble and particle scale, coupled simulations with the volume of fluid model and the discrete element method are performed to investigate the effects of the gas inlet velocity, particle properties and two-orifice bubbling flow on particle fluidization. Three-dimensional simulations are carried out to accurately capture the dynamic changes in the bubble shape and trajectory. A bubbling flow with a closely packed bed is simulated to study the onset of particle fluidization. The obvious phenomena of particle fluidization are presented by both the experiment and simulation. Although an increasing gas inlet velocity promotes particle fluidization, the good fluidization of particles cannot be achieved solely by increasing the gas inlet velocity. When the channel is packed with more particles, the bubbles take a longer time to pass through the higher parti... [more]

The oil pipeline transportation of highly waxy oils when it is cold is accompanied by the deposition of paraffins in the inner surface of the pipeline. This study of the initial properties of the oil; the composition, structure, and nature of the components of normal alkanes in oil; and their influence on the aggregative stability of the resulting system makes it possible to find the best solutions to optimize the conditions of oil transportation with the lowest energy costs. This study shows that, according to the content of solid paraffin (14.0−16.2%), the oils of the Kumkol group of fields in Kazakhstan are highly waxy. They are characterized by high yield loss temperature values (+9−+12 °C), which also correlate with the values of the rheological parameters (τ0 1.389 Pa, 3.564 Pa). The influence of the temperature and shear rate on the shear stress and effective viscosity of the initial oils was studied. At temperatures below 20 °C, depending on the shear rate, there is an increase... [more]

This study examined the multi-phase flow field for a single object and two parallel/series objects under different incoming angles of lateral flow. The volume of fluid model, the Sauer−Schnerr cavitation model, and the six degrees of freedom (DOF) method were adopted to consider simulations of multi-phase flow, phase change, and object movement, respectively. The results show that, for a single object, the degree of asymmetry in the cavity profile depends on the component (the z-component) of the lateral inflow velocity in the direction perpendicular to the initial velocity of the object. As this component increases, the asymmetry of the cavity increases. The cavity length is related to the relative axial speed between the object and the water. For parallel objects, the cavity asymmetry is determined by the superimposed influence of the z-component of the lateral incoming speed and the high-pressure zone induced by the nearby object. The object located downstream relative to the latera... [more]

In inertial confinement fusion, the sub-atmospheric purging through microcapillaries is of great importance to the high gas purity inside the cryogenic target and the low failure rate of experiments. In this study, a non-continuous flow model is developed for this sub-atmospheric purging process and verified through National Ignition Facility experiments to study the evolution of parameters such as pressure and gas composition that are not possible to measure directly. The effects of microcapillary structures and sizes on the transient evacuation−filling behaviors are analyzed, and the periodic purging scheme is optimized. The results show that the extension of evacuation and filling time caused by the elongated microtube can be described as a linear function of microtube length or an exponential decay function of microtube diameter, and the change of the inner diameter has a more drastic effect. The conical-straight composite can effectively reduce the evacuation and filling time whil... [more]

During the temporary plugging fracturing (TPF) process, the pressure response and pumping behavior significantly differ from those observed during conventional fracturing fluid pumping. Once the temporary plugging agent (TPA) forms a plug, subsequent fracture initiation and propagation become more intricate due to the influence of the TPA and early fractures. Factors such as concentration, particle size, and ratio of the TPA notably affect the effectiveness of TPF. This study employs a true triaxial hydraulic fracturing simulation system to conduct TPF experiments with varying particle size combinations and concentrations at both in-fracture and in-stage locations. The impact of different TPA parameters on the plugging effectiveness is assessed by analyzing the morphology of the induced fractures and the characteristics of pressure curves post experiment. Results indicate that combining dfferent particle sizes enhances plugging effectiveness, with a combination of smaller and larger pa... [more]

Blasting is a prevalent technique in deep rock excavation, with the state of rock fragmentation under high in-situ stress conditions being distinct from that under low in-situ stress conditions. A new material point method framework utilizing the generalized interpolated material point and convective particle domain interpolation functions was implemented to simulate the single-hole blasting process, analyze the stress distribution around the blasting hole, and elucidate the mechanism of how ground stress influences the expansion of blasting cracks through the interaction with the blasting load. In addition, the dynamic relaxation method realizes the stress’s initialization. It was concluded that the in-situ stress can increase the compressive stress induced by blasting load, whereas it decreases the caused tensile stress. With the increase in the ground stress, the scale of the cracks decreases. Under the non-isobaric condition, the blast-induced cracks preferentially expand along the... [more]

Drug-resistant Morganella morganii, a rod-shaped, Gram-negative, facultatively anaerobic bacillus belonging to the Enterobacteriaceae family, is a growing worldwide health concern due to its association with high morbidity and mortality rates. Recent advancements in machine learning, particularly Alphafold 2’s protein structure prediction using local physics and pattern recognition, have aided research efforts. This study focuses on the enzymatic activity of aminoglycoside N6′-acetyltransferase (aacA7), a critical transferase enzyme in bacteria that confers resistance to aminoglycosides. AacA7 modifies aminoglycoside molecules by catalyzing the acetylation of their 6′-amino group using acetyl-CoA, rendering antibiotics like kanamycin, neomycin, tobramycin, and amikacin inactive. We propose that Doripenem and OncoglabrinolC can interact with aacA7, potentially modifying its enzymatic activity. Molecular docking analysis of aacA7 with 22 drug targets revealed OncoglabrinolC as the most p... [more]

Electrochemical polishing exhibits high efficiency and simplicity of operation and presents broad prospects in metal field processing. However, the poor conductivity of the surface oxides generated during electrochemical polishing may lead to uneven electrolysis and surface protrusions if not promptly removed. This study combined ultrasonic treatment with electrochemical polishing and adjusted the angle of the ultrasonic jet to investigate the effect of ultrasonic-assisted electrochemical polishing on the removal of protruding microstructures. The study examined the surface morphology, hardness, residual stress, and workpiece contact angle before and after processing. The results demonstrated that ultrasonic assistance can effectively promote electrochemical reactions and improve the removal efficiency of the workpiece surface. With an increase in ultrasonic power and processing time, the corrosion potential of the workpiece decreased, which accelerated the material removal rate. The r... [more]

An expected increase in the demand for aviation transport service will result in the deterioration of the environment and human health, respectively, due to extra greenhouse gas (GHG) emissions. Concerns from EU institutions about the issue have led to legislation initiatives and, later, to development of Regulation (EU) 2023/2405 for the reduction of GHG emissions via the substitution of fossil kerosene with an increasing share of sustainable components. Hydroprocessed esters and fatty acids (HEFAs) are the most commercially acceptable sustainable alternative but their influence on aviation fuel properties needs to be further evaluated in terms of all required and extended properties, as per ASTM D1655. The main properties, together with the rarely reported upon existent gum, water separation, corrosion, and the electrical conductivity of HEFAs and their blends with fossil kerosene were quantitatively evaluated in this study. For every increase of 10% (v/v) of HEFAs, the following fue... [more]