The condition of the bearing is closely related to the condition and remaining life of the rotating machine. Targeting the problem of the large number of harmonic signals and noise signals during the operation of rolling bearings, and given that it is difficult to identify the fault in time, an adaptive orthogonal matching pursuit algorithm (OMP) and an improved K-singular value decomposition (K-SVD) for bearing fault feature extraction are proposed. An adaptive OMP algorithm is applied, which uses the Fourier dictionary to improve the solution method of the OMP algorithm so that it can separate the harmonic components in the signal faster and more accurately. At the same time, the stopping criterion of the adaptive sparsity is improved in dictionary learning. There is no need to manually set the sparsity in the algorithm initialization process, which avoids the problem of algorithm performance degradation due to improper sparsity settings, and improves the efficiency of the K-SVD algo... [more]

There have been numerous studies highlighting the efficacy of various bacteriophages (phages) and phage cocktails in the reduction of pathogens in food. Despite approval from legislative bodies permitting phage use in food processing environments, applied via spray or dip, there is still no information on which spray parameters should be used for successful implementation. The study here investigates phage survival diluted to 1% in distilled water (dH2O) and prepared bottled water (PBW), followed by a subsequent spray application through a fixed nozzle (530 μm) and strainer size (74 × 74 μm), with pressures of 3, 5, and 6 Bar. The survival of the phage was determined through sampling the outputs of the spray system and performing double agar overlay plaque assays. PBW decreased the phage concentration (p = 0.18) more than the dH2O (p = 0.73) prior to spray application. It was found that the PBW phage solution was less affected by the various spray parameters (p = 0.045) than the dH2O (... [more]

Aluminum−silicon (Al−Si) alloys are the most commonly cast aluminum alloys. Fe is the most deleterious element for Al−Si die casting alloys, as its existence causes the precipitation of substantial intermetallics that result in the unsatisfactory mechanical performance of the alloy, such as its ductility. Hence, controlling the morphology and formation of the AlFeSi phase, particularly the β-AlFeSi phase, is vital for improving the ductility of Al−Si die casting alloys. Herein, Ca was added to the A380 alloy, and the morphological changes resulting from the influence of Ca on the AlFeSi phase were characterized. The outcomes revealed that according to different cooling rates, specific amounts of Ca addition (0.01−0.1 wt.%) were capable of refining α-AlFeSi and β-AlFeSi morphology and transforming the β-AlFeSi phase into α-AlFeSi. Moreover, Ca addition could also modify eutectic silicon. The transformation mechanism and refining role of Ca in AlFeSi and the different morphologies of Al2... [more]

This article presents a cloud-based system for the on-line monitoring of tool conditions in end milling. The novelty of this research is the developed system that connects the IoT (Internet of Things) platform for the monitoring of tool conditions in the cloud to the machine tool and optical system for the detection of cutting chip size. The optical system takes care of the acquisition and transfer of signals regarding chip size to the IoT application, where they are used as an indicator for the determination of tool conditions. In addition, the novelty of the presented approach is in the artificial intelligence integrated into the platform, which monitors a tool’s condition through identification of the current cutting force trend and protects the tool against excessive loading by correcting process parameters. The practical significance of the research is that it is a new system for fast tool condition monitoring, which ensures savings, reduces investment costs due to the use of a mo... [more]

We live in the big data era, in which a large amount of information is continuously created, registering all kinds of events, such as those generated in the design, planning, control, and execution of manufacturing, logistics, and supply chain processes [...]

In the stochastic reconstruction of petroleum fractions, the domain configuration for parameters is of great significance to the performance of the model in terms of accuracy and convergence. Based on the stochastic reconstruction model of gas oils, this work investigates the influence of different domains on the simulating accuracy, the convergence rate and the ability to predict detailed composition. In this paper, the parameters to be optimized in the model include histogram distributions and gamma distributions, which are used to represent the structural attributes. In each histogram distribution, the parameters are real numbers between zero and one that should increase progressively. The mean and shape parameters are used as the tuning parameters for gamma distribution. As for the mean, the lower and upper boundaries are configured as fixed values that depend on the predefined values of the structural attributes. For the shape parameter, multiple cases are considered for its upper... [more]

The progress of high-efficiency non-precious metal anode catalysts for direct seawater splitting is of great importance. However, due to the slow oxygen evolution reaction (OER) kinetics, competition of chlorine evolution reaction (ClER), and corrosion of chloride ions on the anode, the direct seawater splitting faces many challenges. Herein, we develop a perovskite@NiFe layered double hydroxide composite for anode catalyst based on Ba0.5Sr0.5Co0.8Fe0.2O3 (BSCF) and NiFe layered double hydroxide (NiFe-LDH) heterostructure. The optimized BSCF@CeO2@NiFe exhibits excellent OER activity, with the potential at 100 mA cm−2 (Ej = 100) being 1.62 V in the alkaline natural seawater. Moreover, the electrolytic cell composed of BSCF@CeO2@NiFe anode shows an excellent stability, with negligible attenuation during the long-term overall seawater splitting with the remarkable self-recovery ability in the initial operation stage, and the direct seawater splitting potential increasing by about 30 mV at... [more]

The purpose of this paper is to investigate the feasibility of a wind−solar hybrid system on and off-grid power system for electricity generation at a selected location in Somalia using the renewable energy optimization software HOMER. The simulation model was successfully applied to find the best simulation results based on the energy-efficient system for the specific load. The technical and economic performance of an on-grid and stand-alone combination of 25 kW wind power and 60 kW solar photovoltaic was investigated. Since the city of Cadaado has not yet installed its own standard modern electricity grid and due to the great need to reduce energy costs in Somalia, a feasibility study was conducted on how to supply electricity to a sampled residential consumption. Based on the basic characteristics of renewable energy sources in central Somalia, the on-grid wind and solar photovoltaic systems could be economically feasible.

Biodiesel can substitute for conventional diesel fuel and contribute to the decarbonization of the transportation sector. To improve biodiesel sustainability and decrease production costs, low-grade fats such as non-edible animal fats must be used. Animal fats are mixed with tissues which must be removed before alcoholysis to avoid biodiesel contamination with nitrogen and phosphorus-containing compounds. Biodiesel was produced by the methanolysis of beef tallow and beef tallow/soybean oil mixtures over calcium heterogeneous catalysts obtained by the calcination of scallop shells. The tallow from fatty bovine tissues was extracted using boiling water, dry microwave treatment, and acetone extraction. The thermal stability and the moisture content of the extracted fats were evaluated by thermogravimetry. The thermograms of fats revealed that microwave treatment, which was faster (3 min instead of 40 min for boiling water and 240 min for acetone extraction) and had the lowest energy consu... [more]

The heat integration feasibility of the proton exchange membrane fuel cell (PEMFC) coupled with the solar-heated direct contact membrane distillation (DCMD) module is evaluated in this study. The additional waste heat from the PEMFC increases the DCMD system’s ability to produce fresh water and electricity. Two systems units to be assessed mainly include a flat plate solar collector, a heat storage tank with an internal heat exchanger, and the DCMD module with and without the PEMFC module. The importance of daily operation continuity is emphasized through a preliminary dynamic simulation and proper sizing of the solar-heated DCMD distillation. Sensitivity analysis is implemented to analyze the relationship between the essential variables and the daily freshwater production. The design variables of both configurations are rigorously optimized in terms of minimum unit production cost (UPC). The proposed heat integration feasibility is evaluated to obtain critical insights on the design s... [more]

The focus of this work is the study of the extractive dividing wall column (EDWC) for separating the azeotropic mixture of dipropyl ether and 1-propyl alcohol with N, N-dimethylacetamide (DMAC) as the entrainer. Three separation sequences are investigated, including a conventional extractive distillation sequence (CEDS), EDWC and a pressure swing distillation sequence (PSDS). The static simulation results showed that the EDWC with DMAC as the entrainer is more economically attractive than CEDS and PSDS. Subsequently, a control structure CS1 based on a three-temperature control loop and a control structure CS2 with the vapor split ratio as the manipulated variable are investigated for the EDWC. Their dynamic control performances are evaluated by facing large feed flow rates and composition disturbances. The results showed that the CS1 can deal with feed flow rate disturbance effectively. However, the transient deviation is large and the settling time is too long when facing feed flow co... [more]

The coupling of individual models in terms of end-to-end calculations for unit operations in manufacturing processes is a challenging task. We present a probability distribution-based approach for the combined outcomes of parametric and non-parametric models. With this so-called Bayesian predictive ensemble, the statistical moments such as mean value and standard deviation can be accurately computed without any further approximation. It is shown that the ensemble of different model predictions leads to an uninformed prior distribution, which can be transformed into a predictive posterior distribution using Bayesian inference and numerical Markov Chain Monte Carlo calculations. We demonstrate the advantages of our method using several numerical examples. Our approach is not restricted to certain unit operations, and can also be used for the more robust interpretation and assessment of model predictions in general.

Efforts to engineer high-productivity crops to accumulate oils in their vegetative tissue present the possibility of expanding biodiesel production. However, processing the new crops for lipid recovery and ethanol production from cell wall saccharides is challenging and expensive. In a previous study using corn germ meal as a model substrate, we reported that liquid hot water (LHW) pretreatment enriched the lipid concentration by 2.2 to 4.2 fold. This study investigated combining oil recovery with ethanol production by extracting oil following LHW and simultaneous saccharification and co-fermentation (SSCF) of the biomass. Corn germ meal was again used to model the oil-bearing energy crops. Pretreated germ meal hydrolysate or solids (160 and 180 °C for 10 min) were fermented, and lipids were extracted from both the spent fermentation whole broth and fermentation solids, which were recovered by centrifugation and convective drying. Lipid contents in spent fermentation solids increased 3... [more]

This article presents the results of research on the possibilities of fragmentation of cultural, and especially agricultural, landscapes in a selected locality in eastern Slovakia, which is currently characterized by a high proportion of large-scale soil units used for growing cereals and crops subsequently used as energy sources (maize and oilseed rape, among others). Slovakia, as the country with the largest average field area in the European Union (EU), is facing a process of fragmentation of these units to counter climate change and increase the resilience of the landscape to erosion, soil fertility, and biodiversity loss. This paper presents a fragmentation method based on the restoration of former dividing lines, mainly formed by dirt roads, based on the historical mapping. The results show that in this way it is possible to achieve denser landscape fragmentation, to create dividing green belts, to increase the resilience of the environment to water and wind erosion, and to creat... [more]

A prediction method applicable to erosion-prone areas of fluorine chemical pipelines is herein proposed. By summarizing the common working conditions in the fluorine chemical industry, a computational fluid dynamics (CFD) model for industrial pipelines is established, and three-dimensional numerical calculations of the flow field in the pipelines are carried out to analyze the characteristics of the hydrodynamic parameters and phase distribution in the flow field, as well as the erosion rate distribution in different areas of the pipelines. The areas in the pipeline that are susceptible to erosion are predicted based on the results. The method has universal applicability and has been applied in many large petrochemical companies. It achieves the function of predicting the areas of severe pipeline erosion in a scientifically sound manner. This paper also details the application of the method in a distillation oil and gas pipeline of a large oil and gas company in western China.

The principle about the nonlinear ultrasonic mixed frequency is introduced. A novel identification method for incipient structural health prognosis is proposed based on heterolateral co-linear mixed-frequency ultrasound to identify the micro-crack in mechanical structures. The modelling analysis methodology by the application of finite element analysis (FEM) is developed to simulate the nonlinear mixed-frequency ultrasonic wave transmission mechanism from the cracks with different depths and the excited frequency. The correlation models between the crack widths and the mixed-frequency nonlinear coefficients are established. An experimental method based on the nonlinear mixed-frequency ultrasonic theory is proposed to actuate the differential and sum-frequency characteristic mixed waves that interact with the defects of materials, which obtains the nonlinear coefficients to identify the depths of cracks in materials. The FEM model is verified to be effective at predicting the width of t... [more]

By increasing the resistance of seeds against abiotic and biotic stress, the possibility of cereal mold contamination and hence the occurrence of secondary mold metabolites mycotoxins decreases. The use of biological methods of seed treatment represents a complementary strategy, which can be implemented as an environmental-friendlier approach to increase the agricultural sustainability. Whereas the use of resistant cultivars helps to reduce mold growth and mycotoxin contamination at the very beginning of the production chain, biological detoxification of cereals provides additional weapons against fungal pathogens in the later stage. Most efficient techniques can be selected and combined on an industrial scale to reduce losses and boost crop yields and agriculture sustainability, increasing at the same time food and feed safety. This paper strives to emphasize the possibility of implementation of biocontrol methods in the production of resistant seeds and the prevention and reduction i... [more]

The use of renewable energy for desalination started in the 1980s, in order to provide a sustainable water supply in windy/sunny areas with water shortages. Nevertheless, this initiative has been generally limited to the R&D field and prototypes, with few units operating under real conditions. The research tradition in this field carried out by the Canary Islands Institute of Technology, based on pilot facilities, resulted in wide expertise on practical issues, as well as a deep knowledge on the state of the art. This paper deals with the most relevant technical aspects to be considered in the optimal design and operation of wind/photovoltaic (PV)-powered reverse-osmosis (RO) systems, focusing on practical indications: appropriate pre-treatment, the use and selection of the RO energy recovery system (ERD), the selection of an energy storage system, key recommendations for the O&M actions in wind- and PV-powered RO systems (extracted from the experience of operating different units in r... [more]

3D auxetic structures, which present negative Poisson’s ratio in the uniaxial compression deformation, is an ideal artificial material for meta-implants because of its lightweight, good material property and suitable porosity for bone recovery compared with conventional meta-biomaterials. Selective laser melting (SLM) is commonly used to produce metallic 3D auxetic structures but limited by the melting temperature and reflect rate of the material, and micro assembled (MA) structures is an alternative manufacturing process. However, the influence of size effect in 3D auxetic structures and the difference of the constitutive model of 3D auxetic structure produced by SLM and MA have not been discussed. In tandem of this, the mechanical property comparison of 3D auxetic structures produced by SLM and MA is conducted and a structural surface layer model for 3D auxetic structures is proposed. The result indicated that both SLM and MA structure can achieve auxetic effect. It is found that the... [more]

This study aimed to analyze and quantify the effect of different ratios of vermicompost, phosphate rock, and sulfur on P solubilization and release by Pseudomonas fluorescens Ur21, and to identify optimal levels of those variables for an efficient biofertilizer. Twenty experiments were defined by surface response methodology based on a central composite design (CCD), and the effects of various quantities of vermicompost, phosphate rock, and sulfur (encoded by −1, 0, or +1) on P solubilization was explored. The results show that the CCD model had high efficiency for predicting P solubilization (R2 = 0.9035). The strongest effects of the included variables on the observed P solubilization were linear effects of sulfur and organic matter (vermicompost), a quadratic effect of phosphate rock, and an interactive effect of organic matter × phosphate rock. Statistical analysis of the coefficients in the CCD model revealed that vermicompost, vermicompost × phosphate rock, and phosphate rock × p... [more]

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.