With the promotion of the dual carbon policy and the process of transforming and upgrading manufacturing, vigorously developing high-tech manufacturing with high-technology content and significant added value has become a powerful driving force to improve the development of the regional economy. In this regard, this research employs the two-stage network SBM-DEA method with undesirable outputs and multi-stage activities involved in the green production process. We examine the green technology innovation efficiency of high-tech manufacturing in the Yangtze River Delta (YRD) region from 2010 to 2020. We divide the activities of the high-tech manufacturing industry into two sub-stages, namely, the research and development (R&D) stage and the result transformation stage. The results are as follows: (1) The efficiency level of green technology innovation in Shanghai is at an outstanding level, having the most significant performance both in the R&D stage at 0.833 as well as in the result tr... [more]

Exposed geo−infrastructures filled with compacted soils experience cyclic wetting−drying effects due to environment and underground water fluctuations. Soil physical and mechanical behaviors are prone to deterioration to a great extent, e.g., swelling, collapse, or even slope failure, resulting in huge losses to human life, safety, and engineering construction. In this paper, hydraulic loading tests of wetting−drying cycles were carried out on compacted fine soil via a one−dimensional pressure plate apparatus equipped with bender elements. The influences of wetting−drying paths on the soil characteristics of moisture content, void ratio and shear modulus were obtained and analyzed. Results showed that cyclic wetting−drying effects weakened the soil’s water retention capacity. It was observed that it was harder for pore water to approach saturation at a lower matric suction level and to be expelled at a higher matric suction level. Typical swelling and shrinkage deformations occurred du... [more]

Leak of fuels and lubricants occurring during exploration, distribution, refining and storage operations is the major cause of environmental pollution due to petroderivatives dispersion. The quick use of a series of physicochemical and biological techniques is needed to drastically reduce the magnitude of damage provoked by these pollutants. Among them, soil washing proved to be an effective alternative to the remediation of hydrocarbon-polluted sites, mainly if combined with surfactant utilization. However, the direct use of surfactants can lead to problems related to the toxicity and dispersion of the resulting by-products, as the majority of marketed surfactants are produced from oil derivatives. In this context, green surfactants appear as a promising alternative to their synthetic counterpart. In the present study, two green surfactants, i.e., a chemically synthesized biobased surfactant and a Starmerella bombicola biosurfactant, were applied in soil decontamination tests using a... [more]

The corn-to-sugar process is difficult to control automatically because of the complex physical and chemical phenomena involved. Because the RNN-LSTN model has been shown to handle long-term time dependencies well, this article focused on the design of a model predictive control system based on this machine learning model. Based on the historical data, we first reduced the input variable dimension through data preprocessing, data dimension reduction, sensitivity analysis, etc., and then the RNN-LSTM model, with these identified key sites as inputs, and the dextrose equivalent value as the output, was constructed. Then, through model predictive control using the locally linearized RNN-LSTM as the predictive model, the objective value of the dextrose equivalent was successfully controlled at the target value by our simulation study, in different situations of setpoint changes and disturbances. This showed the potential of applying RNN-LSTM-Based model predictive control in a corn-to-suga... [more]

Computer numerical control (CNC) lathes are optimized for machining workpieces into rotating shafts or cylindrical shapes of structures. However, because rotating mechanical parts are used on CNC lathes, vibration from spindles, servomotors, hydraulic pumps, and feed screws occurs. Therefore, periodic preventive maintenance is required to minimize vibrations. Additionally, alignment, balance, and adjustment operations are necessary for parts that perform linear or rotational movements. Thus, this study adjusts the tension of the V-belt that drives the spindle of the CNC lathe, analyzes the primary components and the vibrations occurring at the spindle and servomotor, and measures the surface roughness to identify the cutting quality according to the impact of the belt tension. The experimental results show that the peak value of the vibrating component increases as the cutting speed increases. We demonstrate that the optimal vibration characteristics and excellent surface roughness val... [more]

As a damage element, high-speed fragments have a significant effect on the ammunition safety. The impact from the fragments are also one of the basic problems of ammunition safety tests. To clarify the reaction characteristics of combustion, explosion, detonation, and so on, when hypersonic fragments hit insensitive munitions, it is necessary to carry out corresponding research on the deceleration law of hypersonic fragment in the air. In this paper, a 30 mm caliber gun with large chamber, small caliber, and large aspect ratio is proposed to drive high-speed fragments. According to STANAG 4496 standard, a near-cylinder steel fragment with Brinell hardness HB ≤ 270 and mass of 18.6 g was designed. The test system was composed of zone interception velocity measurement, chamber pressure sensor, trajectory tracking system, high-speed camera, and other equipment were also established to obtain the pressure variations in the chamber, the velocity of the fragment, and its flight orientation.... [more]

The increasing demand for electricity in South Africa has led to a rise in the deployment of solar photovoltaic systems. The integration of these systems requires the installation of power transformers to convert the generated DC power into AC power that can be fed into the grid. However, the high cost of these transformers can hinder the widespread adoption of solar PV systems. Consequently, the primary objective of this work is to introduce a novel service-lifetime loss estimation method that acknowledges the unique requirements of transformers facilitating solar photovoltaic applications. In reality, these transformers are required to facilitate a sporadic energy source, which advocates for an appropriate method to assess the cost of their service-lifetime losses and total ownership cost. Thus far, the energy elements of classical coal-power generation are inadequate, and in conformity with operational and financial considerations of solar PVs, a novel method incorporating the outco... [more]

Submarine pipeline gas releases and dispersions can cause safety concerns such as fire and explosion, which can cause serious casualties and property losses. There are many existing studies on the impacts of the horizontal diffusion distances of natural gas leakages from subsea pipelines, but there is a lack of research on the impact of influencing factors on vertical diffusion distances. Therefore, a diffusion model of natural gas leakage from a submarine pipeline is established by using the computational fluid dynamics method (CFD). The influence law and degrees of factors such as water depth at the leakage point, leak orifice size, leak pressure and the ocean current’s velocity on the leakages and vertical diffusion distances of natural gases from submarine pipelines are systematically investigated. The results show that the leaked natural gas jet enters the sea water to form an air mass, which rises continuously under the action of the pressure in the pipe and the buoyancy of the s... [more]

Usually, the ion implantation gases used in semiconductor production are required to be extremely high in purity. Due to the presence of trace CO2 in electronic special gas BF3, the quality of the material is significantly affected, which makes it crucial to impose control on CO2 content. Unlike a series of blank adsorbents reported in other studies, the zinc-loaded adsorbents prepared in this study are intended for the adsorption of CO2 from CO2/BF3. Firstly, the materials were characterized by XRD, BET, SEM-EDS and TG-DSC analysis, etc., and the breakthrough curves of the adsorbents as obtained under different preparation conditions were investigated at 20 °C and 200 kPa. The results show that the adsorption performance reached the optimal level when the activation temperature was 450 °C and a 13X molecular sieve was impregnated by 0.15 mol/L Zn(NO3)2. Moreover, compared with the Zn-13X, the breakthrough time was reduced to 69% and 44% in two adsorption cycles, respectively. Finally,... [more]

The hydrogenation of nitroaromatics to prepare aromatic amines plays a crucial role in the chemical industry. Traditional hydrogenation has the risk of hydrogen leakage from the equipment, and its catalyst has the disadvantage of being easily deactivated and difficult to recover. In this study, we designed an efficient and stable mesoporous catalyst, Pd@SBA-15, which was constructed by impregnating the nanopores of the mesoporous material SBA-15 with palladium nanoparticles. The catalyst was then filled in a micro-packed-bed reactor (MPBR) for continuous flow hydrogenation. The designed continuous flow hydrogenation system has two distinctive features. First, we used mesoporous Pd@SBA-15 instead of the traditional bulk Pd/C as the hydrogenation catalyst, which is more suitable for exposing the active sites of metal Pd and reducing the agglomeration of nanometals. The highly ordered porous structure enhances hydrogen adsorption and thus hydrogenation efficiency. Secondly, the continuous... [more]

This study aimed to exploit the superior properties of TiO2, ZnO, SiO2 and Al2O3 inorganic materials to combine them under pressure and investigate their mechanical properties. The hot pressing technique was used to produce new materials. Varying amounts of alumina such as 0, 5, 10, 20 and 30 wt% in compounds was considered. The produced materials were characterized by SEM, EDS and XRD analyses. The microhardness properties of the materials were studied, and their tribological properties under different wear loads, i.e., 10 N, 20 N and 30 N, were investigated for every specimen. In XRD analysis, it was observed that no significant new peaks were formed regarding increasing alumina content. The SEM and EDS characterization analyses showed that the materials had a two-phase structure with complex boundaries, and no clear grain boundaries were formed. Moreover, the elements in the EDS analyses and the compounds in the XRD analyses were found to be in line with each other. In wear tests, i... [more]

Internet of Health Things plays a vital role in day-to-day life by providing electronic healthcare services and has the capacity to increase the quality of patient care. Internet of Health Things (IoHT) devices and applications have been growing rapidly in recent years, becoming extensively vulnerable to cyber-attacks since the devices are small and heterogeneous. In addition, it is doubly significant when IoHT involves devices used in healthcare domain. Consequently, it is essential to develop a resilient cyber-attack detection system in the Internet of Health Things environment for mitigating the security risks and preventing Internet of Health Things devices from becoming exposed to cyber-attacks. Artificial intelligence plays a primary role in anomaly detection. In this paper, a deep neural network-based cyber-attack detection system is built by employing artificial intelligence on latest ECU-IoHT dataset to uncover cyber-attacks in Internet of Health Things environment. The propos... [more]

A methodology such as near-infrared (NIR) spectroscopy, which enables in situ and in real-time analysis, is crucial to perform quality control of biodiesel, since it is blended into diesel fuel and the presence of contaminants can hinder its performance. This work aimed to compare the performance of a benchtop Fourier Transform (FT) NIR spectrometer with a prototype of a portable, miniaturized near-infrared spectrometer (miniNIR) to detect and quantify contaminants in biodiesel and biodiesel in diesel. In general, good models based on principal component analysis-linear discriminant analysis (PCA-LDA) of FT-NIR spectra were obtained, predicting with high accuracies biodiesel contaminants and biodiesel in diesel (between 75% to 95%), as well as good partial least square (PLS) regression models to predict contaminants concentration in biodiesel and biodiesel concentration in diesel/biodiesel blends, with high coefficients of determination (between 0.83 and 0.99) and low prediction errors... [more]

Water is increasingly being used as a solvent in place of organic solvent in order to meet the demand for green chemical synthesis. Nevertheless, many of the reaction substrates are organic matter, which have low water solubility, resulting in a low reaction interface and limiting the development of organic-water biphasic systems. A surfactant is typically added to the two-phase system to form an emulsion to increase the contact area between the organic phase and the water. Compared to ordinary emulsion stabilized with the surfactant, Pickering emulsion offers better adhesion resistance, biocompatibility, and environmental friendliness. It possesses unrivaled benefits as an emulsifier and catalyst in a two-phase interfacial catalysis system (PIC). In this study, the amine group (NNDB) was employed to alter the surface of graphene oxide (GO). A stable Pickering emulsion was created by adsorbing GO-NNDB on the toluene−water interface. It was determined that the emulsion system had good s... [more]

Radon is one of the 19 carcinogenic substances identified by the World Health Organization, posing a significant threat to human health and the environment. Properly removing radon under ambient conditions remains challenging. Compared with traditional radon−adsorbent materials such as activated carbon and zeolite, metal−organic framework (MOF) materials provide a high specific surface area, rich structure, and designability. However, MOF material powders demonstrate complications regarding practical use, such as easy accumulation, deactivation, and difficult recovery. Ni−MOF−74 was in situ grown on a porous polyacrylic acid (PA) spherical substrate via stepwise negative pressure impregnation. Ni−MOF−74 was structured as one−dimensional rod−shaped crystals (200−300 nm) in large−pore PA microspheres, whose porous structure increased the diffusion of radon gas. The radon adsorption coefficient of a Ni−MOF−74@PA−polyethyleneimine composite material was 0.49 L/g (293 K, relative humidity o... [more]

To improve the non-uniformity of a multi-cylinder marine diesel engine caused by manufacturing assembly errors and performance degradation of the fuel injection system, with the instantaneous speed applied as the control target, the feedback variable of each cylinder’s exhaust temperature was used to obtain the non-uniformity information and the injection quantity of each cylinder was applied as the control variable; the inhomogeneity control was accomplished by modifying the injection pulse spectrum. The model of AVL Cruise M was established and validated by bench test data. The non-uniformity control strategy based on the instantaneous speed and the exhaust temperature of each cylinder was developed in SIMULINK, and the control effect was compared with the closed-loop control of cylinder pressure by software in-loop simulation. The results showed that the non-uniformity control strategy based on exhaust temperature could significantly improve the uniformity of each cylinder; although... [more]

Fiber cannabis has been grown in Lithuania for a long time, but its cultivation technologies have not been widely studied. However, the growing population and consumption forces us to look to alternatives and to make efforts and find solutions to facilitate the cultivation of fiber cannabis because the use of fiber cannabis can be for many different types of products. The aim of the study was to evaluate the impact of the interaction of fibrous cannabis (Cannabis sativa L.) residue and soil on the mechanical properties of the residue and the environment in cultivation technology using a shredding roller. The study determined the effect of the shredding roller on the moisture content of cannabis residues, lignin content, visual changes, and mechanical characteristics of breaking and cutting. Examining cannabis residues according to the dominant different diameters of 5-, 8-, and 10-mm organic cannabis residues, it was found that the highest efficiency of the shredding roller is when rol... [more]

A statistical design of experiments for a rotary fluidized bed agglomeration process is performed to improve both the knowledge of the process and the influence of the process parameters. Agglomerates of a pharmaceutical formulation are manufactured in a laboratory fluidized bed rotor apparatus with a tangential spray nozzle. Particle size is measured in-line over the entire agglomeration process with a spatial filter velocimetry probe installed directly in the process chamber and off-line with dynamic image analysis for comparison. The influence of the process parameters spray rate, spray pressure, rotor speed, and process air temperature on the fluidized bed is investigated using a central composite design. In-line measurement of particle size is possible over the entire rotor process. Spray pressure, spray rate, square of process air temperature, and some interactions proved to be statistically significant. Particle size measured with spatial filter velocimetry and dynamic image ana... [more]

This study proposes the design and application of wearable gloves that can recognize sign language expressions from input images via long short-term memory (LSTM) network models and can learn sign language through finger movement generation and vibration motor feedback. It is difficult for nondisabled people who do not know sign language to express sign language accurately. Therefore, we suggest the use of wearable gloves for sign language education to help nondisabled people learn and accurately express sign language. The wearable glove consists of a direct current motor, a link (finger exoskeleton) that can generate finger movements, and a flexible sensor that recognizes the degree of finger bending. When the coordinates of the hand move in the input image, the sign language motion is fed back through the vibration motor attached to the wrist. The proposed wearable glove can learn 20 Korean sign language words, and the data used for learning are configured to represent the joint coor... [more]

A new Group Contribution Method based on elements and chemical bonds was proposed to predict the enthalpy of evaporation of organic compounds at their normal boiling points. A prediction model was built using 1266 experimental data points, and the accuracy of the model estimations was evaluated using 16 experimental data points. The new method has only 42 groups, a simple way of group splitting, and a wide range of predictions with an average relative error of 5.84%. Furthermore, the inclusion of silicon elements and their chemical bonds in the group library enables the effective prediction of silicon-containing compounds with an average relative error of 2.71%. By analyzing and comparing the other three commonly used methods, it can be concluded that the new method provides accurate and reliable estimation results and has a more comprehensive application range.

Supercritical CO2 (scCO2) is utilized in the supercritical fluid extraction of emulsions (SFEE) to swiftly extract the organic phase (O) from an O/W emulsion. The dissolved substances in the organic phase precipitate into small particles and remain suspended in the water (W) with the aid of a surfactant. The process can be continuously conducted using a packed column in a counter-current flow of the emulsion and scCO2, at moderate pressure (8−10 MPa) and temperature (37−40 °C). To ensure the commercial viability of this technique, the organic solvent must be separated from the CO2 to facilitate the recirculation of both streams within the process while minimizing environmental impact. Thus, the aim of this work was to design a plant to produce submicron materials using SFEE, integrating the recovery of both solvents. First, experimental equilibrium data of the ternary system involved (CO2/ethyl acetate/water) were fitted with a proper thermodynamic model. Then, simulations of the whole... [more]

The global coronavirus pandemic (COVID-19) started in 2020 and is still ongoing today. Among the numerous insights the community has learned from the COVID-19 pandemic is the value of robust healthcare inventory management. The main cause of many casualties around the world is the lack of medical resources for those who need them. To inhibit the spread of COVID-19, it is therefore imperative to simulate the demand for desirable medical goods at the proper time. The estimation of the incidence of infections using the right epidemiological criteria has a significant impact on the number of medical supplies required. Modeling susceptibility, exposure, infection, hospitalization, isolation, and recovery in relation to the COVID-19 pandemic is indeed crucial for the management of healthcare inventories. The goal of this research is to examine the various inventory policies such as reorder point, periodic order, and just-in-time in order to minimize the inventory management cost for medical... [more]

Al−Ni−Er is an essential system in heat-resistant Al alloys. However, the aluminum-rich corner of this system, which has the most practical application significance, has not been fully studied. In this work, the phase equilibria of the Al−Ni−Er system are investigated via experiments and thermodynamic modeling. The isothermal sections of the Al-rich corner of this ternary system at 600 and 700 °C were determined through equilibrated alloys combined with scanning electron microscopy (SEM), electron probe microanalysis (EPMA) and X-ray diffractometry (XRD). In addition, the vertical sections of the Al−Ni−Er system at Al0.7Ni0.3−Al0.7Er0.3 and Al0.8Ni0.2−Al0.8Er0.2 were measured via differential scanning calorimetry (DSC) analysis. A new ternary compound, τ14-Al12Ni2Er3, was discovered. On the basis of the experimental results of this and previous studies, the ternary Al−Ni−Er system was optimized with the calculation of phase diagrams (CALPHAD) method. The calculated isothermal and verti... [more]

The frequency of roof-caving accidents ranks first among all coal mine accidents. However, the scattered knowledge system in this field and the lack of standardization exacerbate the difficulty of analyzing roof fall accidents. This study proposes an ontology-based semantic modeling method for roof fall accidents to share and reuse roof fall knowledge for intelligent decision-making. The crucial concepts of roof fall accidents and the correlations between concepts are summarized by analyzing the roof fall knowledge, providing a standard framework to represent the prior knowledge in this field. Besides, the ontology modeling tool Protégé is used to construct the ontology. As for ontology-based deep information mining and semantic reasoning, semantic rules based on expert experience and data fusion technology are proposed to evaluate mines’ potential risks comprehensively. In addition, the roof-falling rules are formalized based on the Jena syntax to make the ontology uniformly expressed... [more]

One of the most advanced systems of microbial fuel cells is the benthic microbial fuel cell (BMFC). Despite several developments, this strategy still has a number of significant flaws, such as instable organic substrate. Waste material (sugarcane) is used as a substrate in this work to address the organic substrate instability. The process was operated continuously for 70 days. A level of 300 mV was achieved after 33 days of operation, while the degradation efficiencies of Pb (II), Cd (II), and Cr (III) were more than 90%. More than 90% of the removed chemical oxygen demand (COD) was also recorded. The measured power density was 3.571 mW/m2 at 1000 external resistance with 458 internal resistance. This demonstrates that electrons are effectively transported throughout the operation. The Bacillus strains are the most dominant bacterial community on the surface of the anode. This research’s mechanism, which involves metal ion degradation, is also explained. Finally, parameter optimizatio... [more]