In this work, the recovery of valuable metals from Bayer red mud using hydrometallurgical techniques and the subsequent use of the solid remaining after leaching as the principal component of the fired bricks were analyzed. Water, sulfuric acid, and sodium hydroxide were used as leaching agents. Different L/S ratios and contact times were also tested. According to technical, economic, and environmental considerations, the optimal conditions to recover valuable elements from red mud were 2 M H2SO4, in contact for 24 h, with an L/S ratio = 5. Under these conditions, high leaching yields of valuable elements such as La (47.6%) or V (11%) were achieved. After the leaching process, the remaining solid was mixed with clay and water to produce bricks. Two doses of red mud (50 and 80% w) and two different sintering temperatures (900 and 1100 °C) were tested. When the proportion of treated RM in the mix was increased, the compressive strength of the bricks was reduced, but it was increased as t... [more]

Bioscorodite crystallization is a promising process for the proper immobilization of arsenic from acidic metallurgical wastewater, and Acidianus brierleyi is an effective archaeon to oxidize Fe(II) and As(III) simultaneously. This paper deals with the development of an experimentally validated mathematical model to gain insight into the simultaneous processes of Fe(II) and As(III) oxidation via microbial cells and the exopolysaccharide (EPS) matrix, As(V) precipitation, and bioscorodite crystallization, which are affected by several factors. After the mathematical structure was proposed, a model fitting was performed, finding global determination coefficients between 0.96 and 0.99 (with p-values < 0.001) for all the variables. The global sensitivity analysis via Monte Carlo simulations allowed us to identify the critical parameters whose sensitivity depends on culture conditions. The model was then implemented to evaluate the effect of cell concentration, Fe(II) and As(III) concentr... [more]

In this paper, a small centrifugal pump experiment was conducted under conditions of power frequency startup and frequency conversion startup respectively. The evolutionary trends for hydraulic performance parameters with time were obtained, and the transient properties of the two starting modes were revealed with the help of three dimensionless coefficients. This study revealed the similarities and differences between the two starting modes. In both starting modes, the increase of the valve opening caused a time lag for the flow to reach a steady state. Compared with the power frequency startup mode, the frequency conversion startup mode had weaker shaft power shocks and was safer in practice. The dimensionless flow curves maintained a good evolutionary agreement with the corresponding flow curves. The dimensionless shaft power was extremely high at the beginning of startup and then decreased to a stable value.

The greenhouse effect is one of the concerning environmental problems. Farmland soil is an important source of greenhouse gases (GHG), which is characterized by the wide range of ways to produce GHG, multiple influencing factors and complex regulatory measures. Therefore, reducing GHG emissions from farmland soil is a hot topic for relevant researchers. This review systematically expounds on the main pathways of soil CO2, CH4 and N2O; analyzes the effects of soil temperature, moisture, organic matter and pH on various GHG emissions from soil; and focuses on the microbial mechanisms of soil GHG emissions under soil remediation modes, such as biochar addition, organic fertilizer addition, straw return and microalgal biofertilizer application. Finally, the problems and environmental benefits of various soil remediation modes are discussed. This paper points out the important role of microalgae biofertilizer in the GHG emissions reduction in farmland soil, which provides theoretical suppor... [more]

China, as one of the largest grain production countries, is faced with a storage loss of at least 20 billion kilograms each year. The energy consumption from grain bin buildings has been rising due to the preferred environmental demand for the long-term storage of grain in China. A prefabricated phase change material (PCM) plate was incorporated into the bin walls to reduce energy consumption. The physical model of PCM bin walls was numerically simulated to optimize the latent heat and phase change temperature of PCMs for ecological grain storage area. The thermal regulating performance of the prefabricated PCM plate on the grain bin wall was optimized. It was indicated that a higher value of latent heat of the PCM is more suitable for the hotter region for storing grain in bins in this paper. The energy saving did not increase in the same proportion as the increase in latent heat, suggesting a diminishing return. In this study, the optimal latent heat ranged from 180 to 250 kJ/kg. The... [more]

Fc fusion proteins are used as therapeutic agents with unique structures by combining the Fc domain of an antibody with other active proteins, cytokines, and enzymes. Peptide Fc-fusion proteins are complex fusion molecules that possess a structure different from that of monoclonal antibodies (mAbs) and are difficult to express, thereby affecting their quality. Many product/process-related impurities generated during the production of peptide Fc-fusion proteins pose a risk to the robustness of pre-existing three-column platforms for the purification of mAbs. Thus, we first evaluated the effect of pH, conductivity, and dynamic binding capacity (DBC; g of product per liter of resin) on the separation of host cell protein (HCP) and high molecular weight (HMW) and low molecular weight (LMW) proteins in strong cation exchange chromatography and then established an operating range using the design of experiments (DoE). Based on our studies, the optimal removal rates of HCP and HMW were achiev... [more]

Heavy oil and biomass co-gasification has been analyzed through a model developed in Aspen Plus™ v 11.0 software. The model was used to assess main gasification parameters, such as cold gas efficiency, yield, low heating value (LHV), and producer gas composition, using air and oxygen as gasification agents. Subsequently, producer gas energy use in the Rankine cycle was performed using a model developed in GateCycle™ v11.1.2.4.850 software. Likewise, the economic indicators of the integrated Rankine cycle-gasification system were calculated. The economic evaluation was developed through Monte Carlo simulation using Crystalball™. The results showed a LHV producer gas decreasing trend as the equivalence ratio (ER) increased, oscillating between 6.37 and 3.63 MJ/Nm3 for ER values greater than 0.30 in the air co-gasification case, while the scenario that used oxygen presented better LHV results, ranging from 9.40 to 11.79 MJ/Nm3. For air co-gasification, the Rankine cycle efficiency range w... [more]

Fuel cells are considered as efficient and environmentally ecofriendly alternatives for energy production. The oxygen-reduction reaction is important in energy-conversion systems for fuel cells. In this work, rhodium (Rh) and cobalt (Co) alloy nanoparticles were deposited on nitrogen (N)-doped carbon (C) supports (RhCo/NC) using ball milling and thermal decomposition. The RhCo/NC composites were transformed into small nanoparticles with an average diameter of approximately 4 nm. The properties of the as-synthesized RhCo/NC nanocatalyst were characterized through transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy. The catalytic activity of the nanocatalyst for the ORR was investigated. The RhCo/NC nanocatalyst showed good activity for the ORR, long-term durability in chronoamperometry tests, and resistance to methanol crossover in an alkaline solution. This was because of the synergistic effects of the metal alloy. Chronoamperom... [more]

This work presents the numerical modeling of a droplet’s sessile and dynamic behavior on a grooved surface. A droplet is placed on horizontal and vertical sliding conditions to observe its behavior under wettable and non-wettable conditions. The numerical analysis uses the multicomponent multiphase Shan-Chen Lattice Boltzmann Model (SC-LBM). The Cassie−Baxter and Wenzel states are reproduced for the sessile condition, and the enhancement of the contact angle is appreciated under the action of the grooved-ridged horizontal surface. The sliding droplet is analyzed through the Bond number by varying the ratio between the body force and the surface tension number. For Cassie−Baxter and Wenzel wettability conditions, a critical Bond number was discovered above which the sliding droplet will continue to deform indefinitely. The numerical model proved its suitability to predict the gradual deformation of a droplet over a grooved vertical surface subject to a tangential body force until the dr... [more]

Heavy oil and natural bitumen resources in carbonate formations are huge and considered as the promising alternative energy resource to the conventional crude oils. However, the production of such resources is challenging due to the low permeability, high viscosity and significant content of resins and asphaltenes in the composition of heavy oil and natural bitumen. The combination of thermal, chemical and gas enhanced oil recoveries can be a promising method to unlock and upgrade heavy oil and natural bitumen in carbonate reservoirs. In this paper, we propose a novel in-situ liquid-phase oxidation of light hydrocarbons for a revolutionary thermo-gas-chemical enhanced oil recovery method, which can be applied in carbonate heavy oil reservoir formations. It is assumed that the oxidation process is carried out in a downhole well reactor, the products of which are a high temperature mixture of organic carboxylic acids and organic solvents. Here, we present the results of laboratory invest... [more]

It is important to obtain the soil water content threshold (θTHR) for agricultural water management. However, the measurement of θTHR is time consuming and needs specialized and expensive equipment. The accuracy of the empirical estimates is often low. Therefore, the development of a simple, rapid, and accurate prediction method for θTHR is the focus of the present study. The value of θTHR is regarded as the soil water content at the capillary break capacity (θCB). A formula based on field capacity (θFC) and soil bulk density (Db) is proposed to calculate θCB, expressed as θCB=θFC−0.21*1−Db/2.65. Six soils from six published studies on the response of tree physiological processes to water deficit were used to calculate θCB using this formula. The calculated θCB values were compared with the measured θTHR. The results showed that the calculated θCB values were nearly equal to the measured θTHR. A highly significant (adj R2 = 0.9826, p < 0.001) linear relationship with a slope of 0.95... [more]

Since the lack of a specific design method, guidance and user participation in the product innovation design of digital twins, a product innovation design process of a user requirement-driven digital twin combined with flow function analysis is proposed based on the constructed innovation design model of the PPE-PVE-VVE-VPE digital twin. First, to obtain the orientation of the product innovation design, the user requirement knowledge graph is generated on the basis of product functional decomposition to intuitively express the mapping relationship between user requirements and product functional components. Then, composition analysis of the prototype physical entity (PPE) is conducted in the physical domain; flow function analysis identifies the prototype virtual entity (PVE) defects in the virtual domain; the vision virtual entity (VVE) is solved via flow evolution path as well as evaluated and selected from the users’ perspective to display simulation and rehearsal analysis. Finally,... [more]

Tungsten-heavy alloys (WHA) are a pseudo-alloy in which tungsten is the primary phase and remains filled with additives such as Ni−Fe and Ni−Cu. These alloys are widely used to make their applications’ structural, electrical, and electronic components. According to this study, in addition to processing factors, the prime factors affecting the performance of WHAs are microstructural features such as tungsten and matrix composition, powders shapes and sizes, and distributions of tungsten particles in the matrix, as well as interface-bonding strength between the tungsten particle and matrix. This study summarises current developments in WHA processing, microstructure, and mechanical characteristics. For the manufacture of WHAs, various processing methods are discussed, including traditional powder metallurgy (PM), microwave sintering (MW), spark plasma sintering (SPS), and additive manufacturing (AM). SPS process depicts better results when compared with conventional sintering. This revie... [more]

The concern of sustainable supplier selection has been raised recently in organizations’ decision making to enhance their competitiveness. Many tools have been developed to support supplier evaluation, yet the factors of Industry 4.0 (I4.0) have been ignored despite their impact on sustainable performance. Hence, this paper aims to include the technology of I4.0 as the criteria to evaluate the competence of suppliers in sustainability. Multiple-criteria decision making (MCDM) has been used to build decision-making systems; thus, this study employed two advanced methods of MCDM, the ordinal priority approach (OPA) and measurement of alternatives and ranking according to compromise solution (MARCOS) in a fuzzy environment. To test the feasibility of the proposal, five manufacturers of Vietnam’s leather and footwear industry were hypothetically assigned. Firstly, the evaluation criteria were weighted by OPA. Then, the ranking of alternatives was determined by fuzzy MARCOS. The results sho... [more]

The development of a biorefinery is described based on rapid polishing of partially treated sewage with three different species of macrophytes in the recently developed SHEFROL® bioreactor which functions almost entirely on solar and gravitational energy, requiring no chemicals. It was seen that at a hydraulic retention time (HRT) of just 2 h, suspended solids, COD, BOD, total Kjeldahl nitrogen, soluble phosphorus, zinc, copper, nickel, and manganese are reduced to the extents of 92−95%, 76−78%, 77−81%, 56−61%, 60−66%, 43−46%, 45−48%, 30−35%, and 31−33%, respectively. The treated water meets the water quality standards set for the discharge into surface water bodies. M. quadrifolia was seen to be most effective of the three macrophytes, followed by P. stratiotes and S. molesta, as a sewage cleansing agent, but the difference in the performance of the macrophytes was only marginal, and not highly significant statistically (p ≥ 0.5). The paper also shows that it is possible to extract en... [more]

The mainstream adoption of chickpea proteins and lipids requires a thorough understanding of the impact of critical extraction parameters (enzyme use, reaction time, and solids-to-liquid ratio—SLR) and modes of extraction (single-stage extraction—SSE and countercurrent extraction—CCE) on the simultaneous extraction of lipids and proteins from full-fat chickpea flour and economic process feasibility. A kinetics study revealed that 68.5% oil and 87% protein extraction yields can be achieved using 0.5% protease at pH 9.0, 50 °C, 60 min, and 1:10 SLR, highlighting the role of proteolysis and an adequate incubation time on overall extractability. An increased gradient concentration between the matrix and aqueous media solutes at a lower SLR (1:15), and reduced slurry viscosity increased oil and protein extractability to 80 and 91%, respectively. The high-water usage in the SSE was addressed by the development of a two-stage CCE that reduced water usage by 47% while increasing oil and protei... [more]

Myocardial infarction is a type of heart disease marked by rapid progression and high mortality. In this paper, a novel intelligent recognition algorithm of multiple myocardial infarctions using a bidirectional long short-term memory (BiLSTM) neural network classification was proposed. This algorithm was based on morphological feature extraction, which can greatly improve the diagnostic efficiency of doctors for different kinds of myocardial infarction diseases. The algorithm includes noise reduction and beat segmentation of electrocardiogram (ECG) signals from the Physikalisch-Technische Bundesanstalt (PTB) database. According to the medical diagnosis guide, the distance feature of the whole waveform and the amplitude feature of the branch lead waveform are extracted. According to the extracted features, the long short-term memory network (LSTM) and the BiLSTM neural networks are built to classify and recognize heartbeats. The experimental results show that the accuracy of the morphol... [more]

Achieving curved crease surfaces is a current challenge for designers, the field still underexplored. The curve on which the bending is performed can present extremely complicated shapes that must be accurately generated through various technological processes. For this aim, a planar mechanism consisting of an ellipsograph, a conchoidograph and an RRR dyad—whose inner joint generates the targeted connecting rod curve—was proposed in this paper. Parametrizing the lengths of the elements of the RRR dyad, the correlation coefficient of the rotations of the leading elements and the directions of these movements result in different connecting rod curves, which can be used to obtain the folded surfaces; the optimization, according to various criteria, will be explored for the automatic generation of some design solutions. With the help of the Altair program, for some given geometrical data of the mechanism, both the drawing of the curve on plates of different initial shapes and the simulatio... [more]

In Algeria, “Lemzeïet” is prepared by the natural fermentation of wheat. This study aimed to follow the evolution of microbiological and biochemical properties of Lemzeïet with and without vinegar addition for 3, 6, 9 and 12 months. Lactic acid bacteria (LAB) were identified and the microbial count, as well as pH, acidity, protein, fat, ash and starch contents were determined. Results showed that Lemzeïet samples represented a safe product after the gradual absence of fungi. It also contained a significant load of LAB that were cocci or rods, white or yellow, grouped in chain, pair and tetrad. LAB isolates were mannitol positive, grew between 10 and 45 °C, showed resistance at 63.5 °C and the majority were homo-fermentative. Results showed a significant decrease in pH during fermentation regardless of the vinegar addition. Protein content increased up to 14.90% and 15.50% at the end of fermentation. The fat and starch contents decreased after 12 months of fermentation, regardless of th... [more]

A remotely operated underwater vehicle (ROV) is crucial in ocean exploration and underwater missions. An ROV is manipulated through a tether cable by an operator on shore or mother boat, and it can be used for underwater observations or as a robotic arm to take samples back. The position control and movement of an ROV are not stable due to buoyancy, ocean current, and surge waves. To overcome the influence of these disturbances on the ROV, we propose a switch proportional-integral (PI) controller combined with a buck-boost converter (BBC) to process the ROV’s position following. In this paper, a six-axis ROV was designed and implemented. The ROV controller was designed by a NI-roboRIO-based embedded system, which includes a pressure sensor, an accelerometer, six thrusters, and two webcams. The LabVIEW human−machine interface was designed to integrate the control system, sensors, and thrusters. The PI controller was employed to perform the station-keeping and trajectory following. Diffe... [more]

The application of the plant growth regulator 1-(2-chloro-4-pyridyl)-3-phenylurea (CPPU) is extensively used for red-fleshed kiwifruits or ‘Donghong’, but it has toxicological properties. Extra plant growth regulators (PGRs) were screened for partial substitution of CPPU (10 mg L−1) to the crops to minimize the CPPU content. The results showed that CPPU at a concentration of 5 mg L−1 plus 14-hydroxylated brassinosteroid (14-OH BR) at a concentration of 0.15 mg L−1 has a nearly equal effect to CPPU at a concentration of 10 mg L−1; it maintains the kiwifruit yields and quality as well as increases the postharvest time. Transcriptome sequencing data revealed that the regulation of 14-OH BR on kiwifruit growth acts mainly by activating Brassinosteroid (BR) signaling to synergistically and antagonistically stimulate the signaling of other endogenous growth regulators, including auxin (IAA), abscisic acid (ABA), cytokinin (CK), gibberellin (GA), jasmonic acid (JA) and ethylene (ET).

The new generation of data centers is further evolving towards the direction of high speed and intelligence, which puts forward a great demand for the iteration of optical interconnection technology. Three-dimensional integration based on active photonic interposers can achieve the advantages of high integration, high bandwidth and low power consumption, which has become the main direction for next generation optical module technology. The fabrication and assembly of 3D optical modules based on active interposer-integrated edge couplers and TSV are realized in this paper. Different active interposer processes with integrated edge couplers and RDL-TSV-RDL structures are discussed, manufactured, analyzed and evaluated. The problem of the co-fabrication of the TSV and edge coupler was solved, and perfect electrical and optical characteristics were also achieved. Finally, the fabrication of the substrate and the assembly of the 3D optical module were completed. This paper lays a solid foun... [more]

Electrospinning can produce a new composite for coating sensitive bioactive compounds, such as anthocyanins, and the product obtained from this process presents characteristics that potentialize the application of natural pigments in foodstuffs. The present work aimed to develop a new nanofiber composite with incorporated anthocyanins from jussara pulp using polyethylene oxide through electrospinning. A decay in the percentage of anthocyanins during digestion was observed. However, the polymeric solution and composites produced maintained the antioxidant activity, showing their protective effect on bioactive compounds; furthermore, both nanofibers and polymer solution improved the thermal stability of the anthocyanins. Thus, the results obtained potentiate electrospinning composites in processed food products since the nanofibers presented superior thermal stability and antioxidant activity, even after the digestion process in vitro.

Previously, we showed that the crude methanol extracts of Leucas indica flowers exhibited antioxidant properties and in the current study, crude methanol flower extracts of L. indica showed anticancerous properties as evidenced cytotoxicity (MTT assay test) against the selected cancerous cell lines HeLa, HCT116, HL-60, and MCF-7. Therefore, further analysis was performed to isolate and purify the bioactive compound using activity-guided repeated fractionation of the methanol extract by silica gel column chromatography. After collection of different fractions, all the fractions were subjected to TLC analysis and the fractions which yielded the same compounds on TLC were further analyzed for physicochemical and spectroscopic analyses, e.g., UV, IR, 1H NMR, 13C NMR, COSY, HSQC, and mass spectroscopy. The bioactive compound isolated was elucidated as 6-hydroxy-3-(4-hydroxyphenyl)-7-(3,4,5-trihydroxy-6-)(hydroxymethyl)tetrahydro-2H-pyran-2yl)-4H-chromen-4-one. Based on the antioxidant and a... [more]

Stephaniae Tetrandrae Radix (STR) is a commonly used herb with a history of thousands of years. Accumulating evidence shows the therapeutic effect on breast cancer (BC) of STR. Here, we aimed to elucidate the active components and mechanisms of STR against BC. The active components and targets were retrieved and screened from the corresponding databases. A target protein−protein interaction (PPI) network was built and Ingenuity Pathway Analysis (IPA) used to analyze and screen key targets and pathways. Subsequently, molecular docking was performed to visualize the patterns of interactions between components and targets. Finally, the main active components of STR in treating BC were confirmed by in vitro experiments, and 34 common targets were obtained. The PPI network and IPA showed that the key targets were TP53, JUN, CASP3, and so on. Additionally, signaling pathways were enriched. Docking verified that the active components have good binding potential with the key targets, especiall... [more]