Redox flow batteries hold promise as large-scale energy storage systems for off-grid electrification. The electrolyte is one of the key components of redox batteries. Inspired by the mechanism involved in solvents for extraction, a ternary deep eutectic solvent (DES) is demonstrated, in which glycerol is introduced into the original binary ethaline DES. Redox pairs (active substance) dissolved in the solvent have low charge transfer resistance. The results show that the viscosity of the solvent with the ratio of choline chloride to ethylene glycol to glycerol of 1:2:0.5 decreases from 51.2 mPa·s to 40.3 mPa·s after adding the redox pair, implying that the mass transfer resistance of redox pairs in this solvent is reduced. Subsequent cyclic voltammetry and impedance tests show that the electrochemical performance with the ternary DES as the electrolyte in redox flow batteries is improved. When the ratio of 1:2:0.5 ternary DES is used as the electrolyte, the power density of the battery... [more]

As an excellent reducing agent, lime has an important role in the steel production process. Annular Shaft Kiln (ASK) has been widely used in the lime production industry for its low cost, low footprint, high chemical activity, easy construction, and easy maintenance. Due to the high temperature generated inside ASK during operation, it is hard to observe the limestone decomposition process and the field distribution in the lime kiln. The simulation analysis of temperature field, velocity field and decomposition field in the limestone calcination process by CFD provides practical guidance for future lime product quality control, ASK design and operation parameters’ control. This study is based on an ASK that was put into production. Based on the finite volume method, this paper combines the porous medium model and the shrinking core model to establish a set of mathematical models that can describe the temperature and flow field distribution inside the ASK, as well as the limestone decom... [more]

(E)-Resveratrol is a naturally occurring polyphenolic compound in plants with a variety of widely studied health benefits. The bark of Northern American, Canadian, and Northern European conifer species, which is an underutilized by-product generated by forest industries, is a source of (E)-resveratrol, providing a potential value-added product for these industries. Bark may serve as a good alternative to the invasive plant Japanese knotweed (Polygonum cuspidatum), which currently is the leading commercial source of (E)-resveratrol. This work describes a method to extract and purify (E)-resveratrol from conifer bark with high yield and high purity and investigates the relationship between the amount of (E)-resveratrol and the total phenolic contents in the bark of common conifer species. In this work, barks of four conifer species were extracted and the total phenolic contents were determined by Folin−Cicoalteu’s assay. The (E)-resveratrol content was determined by HPLC-MS. A purificati... [more]

Biosorption on fungal pellets constitutes a promising way of removing precious metals, which are often present at dilute concentrations in wastewater. Herein, we studied the Ag and Au biosorption by Aspergillus tabacinus and Cladosporium cladosporioides pellets. For A. tabacinus pellets the optimum pH values for the biosorption of Ag and Au were 5 and 4, respectively, while for C. cladosporioides granules, the best-suited values were 3 and 4, respectively. Biosorption kinetics of both metals were also studied at low adsorbate concentrations (1 mg/L) and the pH values mentioned above, and the contact times that allow maximum recovery of the two metals were defined. At the pH values estimated as optimum, A. tabacinus pellets adsorbed greater amounts of Ag than C. cladosporioides pellets, while for Au the opposite occurred. We found that the pseudo-second-order model adequately represents Ag and Au biosorption kinetics under the conditions tested. Due to the growing demand and limited ava... [more]

The present study aimed to evaluate the antioxidant properties of a phytocomplex product obtained using 10% hydroalcoholic extractive solutions, in equal proportions, from Ribes nigrum, Rubus idaeus, Rubus fruticosus and Fragaria moschata fresh fruits harvested from the spontaneous flora of Romania. These plant products were recognized for their rich antioxidant content. The phytochemical profile was assessed using HPLC chromatography and UV-Vis spectrometry. The obtained results highlighted the presence of complex bioactive compounds with antioxidant actions, namely anthocyanins, proanthocyanins and vitamin C. The antioxidant actions of the hydroalcoholic extractive solutions and the phytocomplex product were evaluated using chemiluminescence, electrochemical and superoxide dismutase (SOD) methods. The experimental results showed evident antioxidant activity in both the hydroalcoholic extracts and the phytocomplex product.

The exploration and development of different carbon nanomaterials happening over the past years have established carbon electrodes as an important electrocatalyst for oxygen reduction reaction. Metal-free catalysts are especially promising potential alternatives for replacing Pt-based catalysts. This article describes recent advances and challenges in the three main synthesis manners (i.e., pyrolysis, hydrothermal method, and chemical vapor deposition) as effective methods for the production of metal-free carbon-based catalysts. To improve the catalytic activity, heteroatom doping the structure of graphene, carbon nanotubes, porous carbons, and carbon nanofibers is important and makes them a prospective candidate for commercial applications. Special attention is paid to providing an overview on the recent major works about nitrogen-doped carbon electrodes with various concentrations and chemical environments of the heteroatom active sites. A detailed discussion and summary of catalytic... [more]

Taking the closed modification of an open sump of a water treatment pump station as the research background, the hydraulic design criteria for the closed modification of the sump are put forward by combining numerical simulation, model test. Based on CFD technology, a water pumping station including closed sump, bellmouth, impeller, guide vane, elbow and outlet sump is simulated, and the hydraulic performance of the schemes under different parameters is analyzed and compared. The top floor clearance, width, back wall distance, and floor clearance of the sump are optimized hydraulically, and the hydraulic design criteria of the closed sump are obtained. The results show that when the recommended optimization parameters of the closed sump in this study are that the top floor height HD is 0.9 DL, the width B is 3.0 DL, the back wall distance T is from 0.4 DL, and the floor clearance C is 0.75 DL, the internal flow pattern and hydraulic of the closed sump is better. (DL is the diameter of... [more]

Background: Bioactive compounds need to resist food processing, be released from the food matrix, and be bioaccessible in the gastrointestinal tract in order to provide health benefits. Bioactive compounds isolated from peach pomace (PP) were encapsulated using four different wall materials to improve their stability and to evaluate the effects of in vitro gastrointestinal digestion, as well as chemometric modeling among obtained encapsulates. Methods: Phenolics and carotenoids content, antioxidant, antihyperglycemic, anti-inflammatory, and cell growth activities were evaluated after gastric and intestinal digestion steps. Chemometrics classification analysis−principal component analysis and hierarchical cluster analysis revealed grouping among encapsulates. Results: The encapsulation of PP bioactive compounds showed a protective effect against pH changes and enzymatic activities along digestion, and thereby contributed to an increase in their bioaccessibility in gastric and intestinal... [more]

A self-assembled MnO2/Mxene composite film was compounded with MXene nanosheets and layered crystalized MnO2 nanosheets using surfactant sodium dodecyl sulfate (SDS) as a soft template. The obtained material was characterized by XRD, SEM, XPS, and FT-IR, which showed that the films have large surface-active functional groups and metal ion flow channels, indicating that the MnO2/Mxene composite films were capable of both the chemical and physical adsorption of the target heavy metal ions. The analysis of adsorption performance showed that the Pb2+ removal rate reached 98.3% at pH 6 and an initial Pb2+ concentration of 30 mg/L, while the maximum adsorption capacity could reach 1235 µmol/g. In addition, the MnO2/Mxene composite film had specific selectivity and recyclability. The reuse study verified that the Pb2+ removal rate reached 96.4% after five cycles, confirming that the MnO2/Mxene composite films had practical application prospects.

The paper presents the dynamics of a 2R planar articulated robot, developed by two original methods. One is the classical “Lagrangian” adapted by the author, and the second method is absolutely original. The dynamics of the robot are based in both cases on the variation of the inertial forces in the mechanism, or practically on the influence of the masses of the moving elements of the robot. The influence of external loads, weights and the load to be transported is also taken into account. Another original element of the work is the choice of speeds in such a way that they correspond to an optimum necessary for the inverse kinematics imposed on the robot. For this reason, the dynamic operation will be quiet and without large variations or vibrations. If the speeds of the two electric motors (preferably stepper motors) areadapted to those recommended by the author, the controller (PID) used will have a very light load. It is even possible to eliminate it if the adjustment of the two ste... [more]

The application of electric arc furnace ladle slag (EAF ladle slag) in cement products might be limited due to the volume expansion and volume instability created by late hydration. Proper control technique should be developed before the reuse of ladle slag (LS). With the addition of aluminum powder in alkali-activated slag pastes, porous materials were produced. By adjusting the activator modulus between 1.25 and 2.00, fine pores were produced in the foamed pastes, and the material densities were controlled between 594 and 1184 kg/m3. The compressive strengths increased from 0.95 to 9.04 MPa with the increase in density. Direct firing tests showed that the produced porous materials could resist fire damage. With low thermal conductivities range from 0.532 to 1.435 W/m·K, the temperatures in the back panel of the materials were below 100 °C, even under flames of 800 °C for 1 h, which were better than marketing rock wool. The alkali-activated technique was proven to be applicable for th... [more]

Viscoelastic damping materials are an effective means to control structural vibration, and are widely used in various fields. In this paper, we use the Dynamic Mechanical Analysis (DMA) characterization data of viscoelastic damping materials and dynamic characteristics experiments to study the dynamic characteristics of structural damping, analyze and summarize the relationship between the performance of damping materials with temperature and frequency, and explore the influencing factors of damping materials on structural vibration. The research shows that temperature and frequency have great influence on the performance of damping material, and the storage modulus and loss factor change regularly. The modal experiment analysis verifies that the viscoelastic damping material has a good suppression effect on structural vibration, which provides a theoretical basis for the development of damping materials with controllable temperature and frequency domains.

Temporary plugging fracturing in a horizontal well with multi-stages and multi-clusters is usually used to improve stimulation efficiency and increase the gas production from shale gas reservoirs. However, the fracture propagation geometry and the mechanism of temporary plugging are still unclear, which restricts the further optimization of temporary plugging fracturing scheme. In this study, taking the Longmaxi shale as the research object and considering the intrafracture and intrastage temporary plugging, the true tri-axial hydraulic fracturing system was used to put forward an experimental method for simulating the temporary plugging fracturing in a horizontal well with multi-stages and multi-clusters. Afterward, the effects of the size combination and concentration of temporary plugging agents and the cluster number in a stage on the fracture geometry created in the secondary fracturing were investigated in detail. The results show that an optimal fracture propagation geometry ten... [more]

To bridge the technology gap between IC-level and board-level fabrications, a fully additive selective metallization has already been demonstrated in the literature. In this article, the surface characterization of each step involved in the fabrication process is outlined with bulk metallization of the surface. This production technique has used polyurethane as epoxy resin and proprietary grafting chemistry to functionalize the surface with covalent bonds on an FR-4 base substrate. The surface was then metalized using an electroless copper (Cu) bath. This sequential growth of layers on top of each other using an actinic laser beam and palladium (Pd) ions to deposit Cu is analyzed. State-of-the-art material characterization techniques were employed to investigate process mechanism at the interfaces. Density functional theory calculations were performed to validate the experimental evidence of covalent bonding of the layers. This manufacturing approach is capable of adding metallic layer... [more]

A wellhead multistage bundle gas−liquid separator combining a gas−liquid cylindrical cyclone (GLCC) with multi-tube bundle components is expected to improve the gas−liquid separation performance. However, there is no unified understanding of the factors influencing the separation performance of the separator. The continuous improvement and applications of the separator are restricted. This paper evaluated the performance of the separator using a numerical simulation method. The results indicate that the separation flow field evolves to be uniform with the increased water cut when the gas−oil ratio and flow rate remain constant. Compared with a 30% water cut, the separation efficiency at a 50% water cut increased by 5.88%. When the gas−oil ratio and water cut remained constant, the swirl effect of the primary separation was enhanced. The separation efficiency increased to more than 70% when the flow rate was 15 m/s. When the flow rate and water cut remained unchanged, the pressure of th... [more]

Low-permeability reservoirs are important to the future growth of oil and gas reserves and production in China. Predicting the effective stress, σe, in reservoirs is vitally important due to its considerable impact on reservoir development through hydraulic fracturing. This paper presents methods for predicting the σe field in ultralow-permeability reservoirs through reservoir−geomechanics coupling, which involve the simulation and coupling of the tectonic stress σ and pore pressure Pp fields based on three-dimensional (3D) geological models. First, 3D geological models were constructed based on basic data for the oilfield where the reservoir of interest is located. Then, finite element and finite difference simulations were performed to construct the σ and Pp fields, respectively, in the reservoir. Different types of initial σe were coupled based on 3D geological models. Subsequently, a dynamic σe field in the reservoir was established based on oilfield production data in conjunction... [more]

To solve the problems of high labor intensity, low efficiency, and frequent errors in the manual identification of cone yarn types, in this study five kinds of cone yarn were taken as the research objects, and an identification method for cone yarn based on the improved Faster R-CNN model was proposed. In total, 2750 images were collected of cone yarn samples in real of textile industry environments, then data enhancement was performed after marking the targets. The ResNet50 model with strong representation ability was used as the feature network to replace the VGG16 backbone network in the original Faster R-CNN model to extract the features of the cone yarn dataset. Training was performed with a stochastic gradient descent approach to obtain an optimally weighted file to predict the categories of cone yarn. Using the same training samples and environmental settings, we compared the method proposed in this paper with two mainstream target detection algorithms, YOLOv3 + DarkNet-53 and F... [more]

Weak signals in risk analysis digitalization are of great importance for preventing major accidents in risk analysis in the process industry, especially for process operations and production. However, some of the negative impacts are incorrect operational risk identification, significant inventory carrying costs, disruption of risk frequency, and risk consequence analysis, all of which will signal inaccurate information about unforeseen and current dangers in process facilities and operational environments. While the positive impacts are viewed as an early warning system that provides information on operational risk system status, the identification of potential risk weaknesses in process facilities, indicators of a transition or an emerging problem that may become significant in the future, highlighting future assumptions, challenge our views of the future and expand the selection of a processing facility. Lastly, weak signal identification in the digitalization of risk analysis can p... [more]

Heart myocardia are critical to the facilitation of heart pumping and blood circulating around the body. The biaxial mechanical testing of the left ventricle (LV) has been extensively utilised to build the computational model of the whole heart with little importance given to the unique mechanical properties of the right ventricle (RV) and cardiac septum (SPW). Most of those studies focussed on the LV of the heart and then applied the obtained characteristics with a few modifications to the right side of the heart. However, the assumption that the LV characteristics applies to the RV has been contested over time with the realisation that the right side of the heart possesses its own unique mechanical properties that are widely distinct from that of the left side of the heart. This paper evaluates the passive mechanical property differences in the three main walls of the rat heart based on biaxial tensile test data. Fifteen mature Wistar rats weighing 225 ± 25 g were euthanised by inhal... [more]

The three products hydrocyclone screen (TPHS), a branch of the hydrocyclone, effectively removes the fish-hook effect, which has been used in the industrial field. The current cylindrical screen in the TPHS generates the characteristic flow known as the screen underflow, which has a significant impact on device performance. To investigate the flow behaviour of the fluid passing through the screen, a combination of a dynamic analysis and a numerical simulation was used. The permeating process in the TPHS was abstracted by a simple fan mode in this work to generate the flow-rate equations and the driving-force models. The pressure difference was the driving force for the screen penetration in the ideal fluid, but it also included a viscous force in the viscous fluid. Furthermore, at the same inlet velocity, the viscous fluid had a higher flow rate than the ideal, indicating that the viscosity promoted the fluid penetration. Meanwhile, as the inlet velocity increased, the mass flow of the... [more]

This paper presents the development of prediction models for pressure loss and classification efficiency in classifiers. Classifiers belong to one of the most important classification devices in gas particle processing and a fast and accurate determination of pressure loss and cut size is of great interest. The first model developed in this work allows the calculation of pressure loss as a function of geometric and operational parameters. It is based on a number of measured values that are obtained from previous numerical simulations (CFD). The maximum deviation of the model is less than 20% and the model operates in real time. However, the model requires calibration for each type of classifier. The second model for classification efficiency is based on a simplified two-dimensional approach in which the flow profile and particle trajectories are determined exclusively for the area between two classifier blades. The model is applicable for all geometrical and operational parameters and... [more]

AlxGa1−xN nanowires are the key materials for next-generation ultraviolet (UV) detectors. However, such devices have a low quantum efficiency caused by the introduction of defects and impurities throughout the preparation process of nanowires. Herein, the effects of different interstitial defects and vacancy defects on the electronic structure of Al0.5Ga0.5N nanowires are investigated using density functional theory calculations. Our results successfully discovered that only the formation of an N interstitial defect is thermally stable. In addition, the introduction of different defects makes the different nanowires exhibit n-type or p-type characteristics. Additionally, different defects lead to a decrease in the conduction band minimum in band structures, which is the major cause for the decrease in work function and increase in electron affinity of Al0.5Ga0.5N nanowires. What is more, the calculation of the partial density of states also proved that the interstitial defects contribu... [more]

In material management, the inventory systems may have good management aspects in terms of materials; however, this negatively affects the relationship between the facility and customers. In classical inventory models, arriving demands are satisfied immediately if there is enough on-hand inventory. Traditional inventory models consider optimization problems and find the optimal policy of decision variables without computing the stationary distribution of the inventory states for random demand. Hence, a detailed analysis of inventory management systems requires a joint distribution of system stock levels and the number of requests to be investigated thoroughly. This research provides a new stochastic mathematical model for inventory systems with lead times and impatient customers under deterministic and uniform order sizes. The proposed model identifies the performance measures in a stochastic environment, analyzing the properties of the inventory system with stochastic and probabilisti... [more]

To evaluate silver nanoparticles’ (AgNPs) therapeutic and clinical potentials, antibacterial action, blood compatibility, and antiplatelet activities are the main concerns for toxicity profiling. Heat-denatured lysozyme-mediated formulation stabilized the AgNPs, thereby providing more bactericidal activity and blood compatibility. The study of the synthesis of AgNPs suggests the rapid and cost-effective formulation of AgNPs by one-step reaction using a 10:1 ratio of silver nitrate and lysozyme by incubating at 60 °C for two hours. Characterization of AgNPs was analyzed by UV−Visible spectroscopy, DLS, TEM, EDX, XRD, AFM, and FTIR, followed by antibacterial, hemocompatibility, and platelet aggregation testing. The average size of synthesized AgNPs was found to be 94.10 nm with 0.45 mV zeta potential and 0.293 polydispersity index by DLS. The TEM and EXD results indicated homogeneously 28.08 nm spherical-shaped pure formations of AgNPs. The XRD peaks showed the synthesis of small AgNPs w... [more]

Since shale gas mainly occurs in shale pores, research on pore structure characteristics is the key to understanding the shale gas accumulation mechanism. The pore structure of the Lower Carboniferous Dawuba Formation shale in the Qianxi area, represented by the well QSD-1, which obtains a daily shale gas flow of 10,000 m3 and represents an important breakthrough in the investigation of marine shale gas in the Upper Paleozoic region of southern China, is characterized by high-pressure mercury compression experiments and low-temperature gas adsorption (N2 and CO2) experiments with whole pore size. The main controlling factors affecting the pore development of the shale are discussed. (i) The micropores and mesopores are more developed in the shale, and the macropores are the second most developed in the shales of the Dawuba Formation in the Qianxi area, among which the mesopores and macropores contribute most to the pore volume and the micropores and mesopores contribute most to the por... [more]