The present paper is focused on the analysis of Ni2+, Co2+, Fe3+, and Ho3+ ion co-reduction in the background equimolar NaCl-KCl melt at 973 K using the method of cyclic voltammetry. It was found that the co-reduction potentials of Ho3+ and iron triad ions differ greatly. The depolarization of metallic holmium electrodeposition on one of the iron triad metals preliminary deposited on the tungsten electrode was determined. This process resulted in the formation of the HoxNiy, HoxCoy, and HoxFey intermetallic compounds. It was observed that the HoxNiy, HoxCoy, and HoxFey intermetallic compounds may be synthesized in a kinetic regime. The influence of the current density, electrolytic bath composition, and electrolysis time on the composition of the obtained intermetallic compounds was studied. The possibility of synthesizing cathode deposits composed solely of intermetallic compounds is verified. It is demonstrated that the intermetallic compounds may be formed by the addition of the iro... [more]

Liquified natural gas (LNG) manipulator arms have been widely used in natural gas transportation. However, the automatic docking technology of LNG manipulator arms has not yet been realized. The first step of automatic docking is to identify and locate the target and estimate its pose. This work proposes a petroleum pipeline interface recognition and pose judgment method based on binocular stereo vision technology for the automatic docking of LNG manipulator arms. The proposed method has three main steps, including target detection, 3D information acquisition, and plane fitting. First, the target petroleum pipeline interface is segmented by using a color mask. Then, color space and Hu moment are used to obtain the pixel coordinates of the contour and center of the target petroleum pipeline interface. The semi-global block matching (SGBM) algorithm is used for stereo matching to obtain the depth information of an image. Finally, a plane fitting and center point estimation method based o... [more]

A temporary plugging agent is an effective tool for increasing production in old wells. By considering the temporary plugging materials used in the remote WY area, three concentrations and five ratios under different fracture widths were designed and optimized. Thus, the fracture diversion under true triaxial stress was studied. The results showed that when the fracture widths were 2.0, 4.0, and 6.0 mm, the corresponding optimal plugging scheme was that the concentrations of the temporary plugging agent were 12.0, 18.0, and 18.0 kg/m3 and the ratios of 20−70 mesh to 200−300 mesh temporary plugging agent were 4:1, 2:1 and 4:1, respectively. When maintaining the same horizontal stress, an increase in the axial stress was accompanied by an increase in the fracture pressure; the initial fractures almost propagated along the direction of the horizontal maximum principal stress, but the shapes of the turning fractures were different. When the axial stress was the same, an increase in the hor... [more]

Power lithium battery is an important core component of electric vehicles (EV), which provides the main power and energy for EV. In order to improve the estimation accuracy of the state of charge (SOC) of the electric vehicle battery (E-cell), the extended Kalman filter (EKF) algorithm, and backpropagation neural network (BPNN) are used to build the SOC estimation model of the E-cell, and the self-learning characteristic of BP neural network is used to correct the error and track the SOC of the E-cell. The results show that the average error of SOC estimation of BP-EKF model is 0.347%, 0.0231%, and 0.0749%, respectively, under the three working conditions of constant current discharge, pulse discharge, and urban dynamometer driving schedule (UDDS). Under the influence of different initial value errors, the average estimation errors of BP-EKF model are 0.2218%, 0.0976%, and 0.5226%. After the noise interference is introduced, the average estimation errors of BP-EKF model under the three... [more]

The dynamic characteristics of thermal energy play an important role of multi-scale coupling among heterogeneous energy sources in integrated energy systems (IES). In Part I, for the purpose of accurately describing the dynamic processes of thermal energy transmission, the theoretical approach and models were proposed and verified by numerical simulation. In this part, an innovative analytical method based on entropy flow was derived on the basis of theory developed in Part I, which can assess the quantity and quality of thermal transport. A comparative case study indicates that the change trend of entropy flow of each node is consistent with the change of available power, but independent of temperature. The node entropy flow is increased compared with the algebraic sum of branch entropy flow, which reflects the phenomenon of entropy generation in the mixing process; while the change of available power is just the opposite. This means the irreversible entropy generation at the node lea... [more]

In wind tunnels, the Mach number needs to be precisely monitored and controlled. It is difficult to obtain the Mach number directly online, especially when the wind tunnel system is operating in multiple modes. To deal with this problem, a Mach number prediction algorithm based on the kernel partial least squares method is proposed for multi-mode wind tunnel systems. First, in order to reflect real-time changes, the time-slice partial least squares regression method is adopted. Then, in order to enable the model to represent information about the whole working mode divided by key process variables, the mean-value partial least squares model is established and is compared with the time-slice model. Then, considering that wind tunnel systems exhibit strong nonlinear characteristics, the kernel partial least squares method, which is suitable for nonlinear systems, is used to predict the Mach number. The results show that the mean-value model is better than the time-slice model, the models... [more]

It is very important to accurately describe the dynamic processes of thermal energy transmission for coupling with Integrated Energy System (IES). In order to study the thermodynamic characteristics of heat supply, this paper theoretically suggested a generalized model of entropy flow by deducing the expression of entropy conduction and convection based on thermodynamic law and heat transfer analysis. Taking temperature and entropy as the intensity and extension properties, the equivalent distributed and lumped parameter models are established to describe the features of heat loss and transmission delay. The effectiveness of current models is verified by comparing with solutions of conventional Partial Differential Equations (PDE) of heat transfer. The numerical simulation and verification procedure were conducted by Matlab/simulink. The proposed models were applied to simulate the response of temperature and entropy flow of a pipe with length of 100 m under different discrete conditio... [more]

The performance of artificial neural networks (ANNs) is highly influenced by the selection of input variables and the architecture defined by hyper parameters such as the number of neurons in the hidden layer and connections between network variables. Although there are some black-box and trial and error based studies in the literature to deal with these issues, it is fair to state that a rigorous and systematic method providing global and unique solution is still missing. Accordingly, in this study, a mixed integer nonlinear programming (MINLP) formulation is proposed to detect the best features and connections among the neural network elements while propagating parameter and output uncertainties for regression problems. The objective of the formulation is to minimize the covariance of the estimated parameters while by (i) detecting the ideal number of neurons, (ii) synthesizing the connection configuration between those neurons, inputs and outputs, and (iii) selecting optimum input v... [more]

Over the last decade, there has been an increased interest in public health measures concerning food quality and drug safety in supply chains and logistics operations. Against this backdrop, this study systematically reviewed the extant literature to identify gaps in studying food quality and drug safety, the proposed solutions to these issues, and potential future research directions. This study utilized content analysis. The objectives of the review were to (1) identify the factors affecting food quality and possible solutions to improve results, (2) analyze the factors that affect drug safety and identify ways to mitigate them through proper management; and (3) establish integrated supply chains for food and drugs by implementing modern technologies, followed by one another to ensure a multi-layered cross-verification cascade and resource management at the different phases to ensure quality, safety, and sustainability for the benefit of public health. This review investigated and id... [more]

The thermophysical properties of a refrigerant can be modified via adding metal organic frameworks (MOF) to it. Understanding the adsorption−diffusion process of the mixture in MOFs at the molecular level is important to further improve the efficiency of the organic Rankine cycle. The adsorption and diffusion of R32/R1234yf in MOF-200 was investigated by molecular dynamics simulation in the present work. The results show that the number of adsorbed molecules of R32 in MOF-200 per unit mass is higher than that of R1234yf in the pure fluid adsorption system. The adsorption capacity of the mixture is lower than that of a pure working medium due to competitive adsorption. For both pure and mixed refrigerants, the adsorption heat of R32 in MOF-200 is smaller than that of R1234yf. Compared with R1234yf, the self-diffusion coefficient of R32 in MOF-200 is larger because of the lower diffusion activation energy.

(Cinnamomum genus) essential oil is commonly used in food preparation and traditional medicines, with a broad spectrum of biological activities. However, research on the extraction of essential oils (EOs) from C. verum cultivated locally in Vietnam is currently limited. Therefore, in this study, the chemical compositions and bioactivities of EOs from the bark and leaves of C. verum collected from the Thai Nguyen and Yen Bai provinces of Vietnam were investigated. The EOs samples were extracted by using water distillation, organic solvent (n-hexane) and ultrasound-assisted (in n-hexane solvent) extraction methods. The chemical composition of the obtained EOs were analyzed by GC-FID and GC/MS analyses. Results showed that the major chemical compositions of C. verum EOs were: (E)-cinnamaldehyde, trans-cinnamic acid, cinnamyl acetate, and benzaldehyde. Furthermore, C. verum EOs exhibited inhibitory activities against two tested cancer cell lines and four bacterial strains. These findings p... [more]

Biomass waste from harvestable output is produced in significant quantities by agricultural and forestry processes and can have detrimental effects on the ecosystem. Therefore, biomass derived from the waste in the environment has been recognized as a potential source for preparing functional materials in recent years. In this study, activated carbon (ACs) was fabricated and characterized from Phyllostachys edulis (Moso bamboo) using single-step potassium hydroxide (KOH) activation at different temperatures (500 °C to 1000 °C). The prepared ACs were characterized for surface morphology, surface area, functional groups and crystallinity using scanning electron microscopy (SEM), Brunauer−Emmett−Teller (BET) analysis, Fourier transform infrared (FTIR) and X-ray diffraction (XRD), respectively. The SEM revealed well-formed pores on the surface of all ACs, while BET analysis revealed the presence of microporous (≤800 °C) and mesoporous (>800 °C) structures. SBET surface area and total pore... [more]

Casing deformation caused by fault and fracture sliding derived from fracturing has attracted growing attention. Casing deformation frequently occurs during the hydraulic fracturing process in the Sichuan Basin. Although its mechanism has been intensively studied, this issue is becoming increasingly severe and demands immediate solutions, especially in the shale gas blocks of Changning-Weiyuan-Zhaotong. The present study summarizes and analyzes the research progress relevant to casing deformation based on the existing literature. It is shown that the casing deformation rate of the deflection point on the shale gas horizontal well is much higher than that of other places and that shear deformation is the dominant form. The main factors influencing the casing deformation of shale gas horizontal wells include weakened strength of the collapsing casing, geological factors, cement, cement quality sheath, fracturing engineering factor, etc. We propose to reduce casing deformation by optimizi... [more]

The recent outbreak of COVID-19 around the world has caused a global health catastrophe along with economic consequences. As per the World Health Organization (WHO), this devastating crisis can be minimized and controlled if humans wear facemasks in public; however, the prevention of spreading COVID-19 can only be possible only if they are worn properly, covering both the nose and mouth. Nonetheless, in public places or in chaos, a manual check of persons wearing the masks properly or not is a hectic job and can cause panic. For such conditions, an automatic mask-wearing system is desired. Therefore, this study analyzed several deep learning pre-trained networks and classical machine learning algorithms that can automatically detect whether the person wears the facemask or not. For this, 40,000 images are utilized to train and test 9 different models, namely, InceptionV3, EfficientNetB0, EfficientNetB2, DenseNet201, ResNet152, VGG19, convolutional neural network (CNN), support vector m... [more]

Fuel cell electric vehicles (FCEV) are developing quickly from passenger vehicles to trucks or fork-lifts. Policymakers are supporting an ambitious strategy to deploy fuel cell electrical vehicles with infrastructure as hydrogen refueling stations (HRS) as the European Green deal for Europe. The hydrogen fuel quality according to international standard as ISO 14687 is critical to ensure the FCEV performance and that poor hydrogen quality may not cause FCEV loss of performance. However, the sampling system is only available for nozzle sampling at HRS. If a FCEV may show a lack of performance, there is currently no methodology to sample hydrogen fuel from a FCEV itself. It would support the investigation to determine if hydrogen fuel may have caused any performance loss. This article presents the first FCEV sampling system and its comparison with the hydrogen fuel sampling from the HRS nozzle (as requested by international standard ISO 14687). The results showed good agreement with the h... [more]

In order to reveal the inducing factors and safety dynamic evolution mechanism of frequent personal injury accidents under a low carbon manufacturing process, a nonlinear safety dynamic evolution model of a distributed low carbon manufacturing system with large time delay is established. The established model is then verified by simulation results from mathematical analysis and dynamic evolution. Moreover, qualitative analysis on nonlinear safety dynamic evolution and the trend of human−machine safety under a low carbon manufacturing process is investigated. Finally, an application case of the established model is studied. The key results are as follows: (1) There are four dynamic regions, namely the safety area I, the deterioration area II, the asymptotically stable safety area III, and the enhancement area IV of the safety ability in the interaction evolution model of carelessness and safety levels; (2) There are two singularities in the dynamic evolution model of the man−machine saf... [more]

In order to promote the wind monitoring accuracy and provide a quantitative planning method for met mast layout in practical projects, this paper proposes a two-stage layout method for met mast based on discrete particle swarm optimization (DPSO) zoning and micro quantitative siting. Firstly, according to the wind turbines layout, rotational empirical orthogonal function and hierarchical clustering methods are used to preliminarily determine zoning number. Considering the geographical proximity of wind turbines and the correlation of wind speed, an optimal macro zoning model of wind farm based on improved DPSO is established. Then, combined with the grid screening method and optimal layout evaluation index, a micro quantitative siting method of met mast is proposed. Finally, the rationality and efficiency of macro zoning method based on improved DPSO, as well as the objectivity and standardization of micro quantitative siting, are verified by an actual wind farm.

(Morula tree) is one of the indigenous trees bearing wild fruits with various applications in the African communities. Wine is a globally known beverage usually made from grapes; however, recently, other fruits, including wild fruits with a considerable amount of sugars, can be used for making wines. The marula fruit wine is also important in many communities for cultural activities and can be enjoyed by people of varying age groups depending on the age of the product. In recent years, there has been growing interest in shifting from traditional marula winemaking to developing technologies for the marula winemaking process and commercialisation. The process of marula winemaking is similar to the production of grape wines, which entails collection, selection and washing of the fruits; extraction of the juice and mashing; formation and removal of the scum; and ultimately spontaneous fermentation of the resulting juice. The new process in marula winemaking would take into consideration th... [more]

The zeolitic imidazolate framework-8 (ZIF-8), as a kind of MOF, is widely used in sensors, gas storage/separation, drug delivery, and catalysis due to its adjustable porous structure, high surface area, and excellent chemistry tunability. ZIF-8 is constructed by Zn2+ and 2-methylimidazole and synthesized in the methanol solution. In this paper, we explored the influence of the reused methanol solution for the structure and properties of the synthesized ZIF-8. The as-synthesized ZIF-8 was characterized by an X-ray diffraction instrument (XRD), a scanning electron microscope (SEM), a specific surface area analyzer (BET), and Fourier transform infrared spectroscopy (FT-IR). The results show that the reused methanol solution does not change the phase, porous structure, and BET surface area of ZIF-8. However, the particle size of ZIF-8 increases from 50 nm to 5 um and the productive rate decreases to 7.4% when the methanol solution is reused four times. This work provides new insight into t... [more]

Researching the moving speed of particles in a drum is helpful to the optimal design of the rotating device. In this paper, the average mixing velocity of flake particles with different shapes in an elliptical drum is studied. In detail, the mixing systems of rectangular, triangular, and circular flake particles and circular particles are studied; the rollers with different eccentricities are studied; the velocity and periodic variation characteristics of the particle system at 15 rpm and 45 rpm are compared and analyzed; the variation curves of particle average velocity, velocity peak fitting curve (PFC), velocity trough fitting curve (TFC), and velocity fitting under various working conditions are drawn. The results show that the average velocity fluctuation range of the particle system increases gradually with the increase of the eccentricity of the rotating device and the volume of flake particles; the fluctuation of particle average velocity fitting curve and PFC curve in the elli... [more]

Using a water-insoluble β-cyclodextrin-epichlorohydrin copolymer (β-EPI) as an adsorbent to remove carbamazepine (CBZ), an anti-epileptic drug often found both in hospital and urban wastewater, has been validated. The effect of several physicochemical parameters on CBZ retention onto β-EPI, such as contact time, adsorbent dosage, CBZ initial concentration, pH, salts, and temperature, was assessed. The adsorption process occurs in a very short time, less than 20 min, and depends on CBZ concentration and β-EPI amount used. Changes in pH and salt presence, regardless of the type of cation or anion used, do not significantly affect the system’s efficiency. Desorption experiments were also performed, and methanol has proven to be the best CBZ extraction medium; it was also found that the polymer can be recovered and reused for at least five cycles, which makes it cheap and environmentally friendly. Advanced oxidation processes were also tested for CBZ removal by synthesizing a β-EPI polymer... [more]

This paper examines a novel approach to activated carbon (AC) production that uses pea waste (PW) and to what extent it is economically competitive with current production methods. Additionally, the outcome is to provide a detailed economic analysis to understand whether this process is viable. The focus of this production route and the economic analysis will be on a United Kingdom (UK) basis. The plant will be located within the north UK to minimise storage and transportation costs. It also has extensive links to other clusters of nearby industries that would produce from this process in air pollution control or wastewater treatments. The overall production process is detailed, and detailed equipment specifications, including the sizing of equipment and utility requirements, were also given. Material balance calculations are carried out to assess the performance and improve process design. An economic analysis is performed to study the potential of biomass-to-AC conversion costs and c... [more]

In the current literature, information can mainly be found about free and hindered settling of isometric particles in Newtonian and non-Newtonian fluids. These conclusions cannot be used to describe the sedimentation of non-isometric particle in non-Newtonian fluids. For this reason, we have carried out systematic experiments and calculated the correlation of the hindered settling velocity of a cloud of non-isometric particles in high-viscosity and pseudoplastic liquid. The experiments were performed in transparent model fluids, namely, glycerine (a Newtonian fluid) and an aqueous solution of carboxylmethylcelulose CMC (a non-Newtonian pseudo-plastic liquid). These fluids have similar rheological properties, for example, the fresh fine-grained cementitious composites HPC/UHPC. The experiments were carried out with steel fibers with a ratio of d/l = 0.3/20. The settling velocity was determined for fiber volumes from 1% to 5%. While it is known from previous studies that for spherical pa... [more]

This paper set out to establish the dynamics model of shaft torsional vibration for direct-drive wind turbine with the phenomenon of unstable shaft system torsional vibration. The stability of the equilibrium point of the dynamical model is investigated, and the Routh−Hurwitz stability criterion is used to obtain a range of values for the bifurcation control parameters. For the stable equilibrium point, the stability domain of the system is calculated by constructing the Lyapunov function. The sensitivity analysis of system parameters is carried out to obtain the law of the effect of system parameters on system stability of the torsional vibration system. The results are substituted for example calculations, and the results verify the correctness of the theoretical analysis conclusions. It is proved that it is feasible to analyze the torsional vibration characteristics of the direct-drive wind turbine shaft system by using the principle of Routh−Hurwitz stability, etc., which provides... [more]

The energy crisis and the adaptation of the global energy structure promote the development of renewable energies, in particular solar energy, also for syngas production. In this work, attention was focused on solar devices, necessary to provide high-temperature heat for the reduction reaction of metal oxides involved in the chemical looping driven by solar energy. Thermochemical processes for synthetic-gas production and CO2 sequestration were investigated using a concentrating solar thermal system. This paper proposes a useful forecasting model of the receiver temperature to make a realistic estimate of the system’s producibility for the different periods of the year. The model proposed was validated in the winter season, and the predicted temperature varied below 5% considering the real experimental data (442−472 °C). The validated model was used to evaluate the temperature receiver in spring and in summer, when the thermal level is reliable for thermochemical processes. From the sp... [more]