Editor’s Choice Articles

In recent years, we have seen an increasing dependency between different urban critical infrastructures, which raises the demands on their analysis and cybersecurity. Current open-source solutions do not provide simulations of interconnected data networks and power grids, which are essential for analysing of both infrastructures weak parts and reducing the risk of emerging threats. The main purpose of this paper is to describe the design of a simulation platform that provides this type of simulation to customers using the virtual user interface. The paper describes the development of a complex model of interconnected power and data infrastructures. Created virtualization platform that consists of several open-source tools is described in detail. Outputs of this paper can be used for analysis of critical infrastructures at the level of urban networks. Full article

Emerging contaminants (ECs) include a diverse group of compounds not commonly monitored in wastewaters, which have become a global concern due to their potential harmful effects on aquatic ecosystems and human health. In the present work, six ECs (ibuprofen, diclofenac, erythromycin, triclosan, imidacloprid and 17α-ethinylestradiol) were monitored for nine months in influents and effluents taken from four wastewater treatment plants (WWTPs). Except for the case of ibuprofen, which was in all cases in lower concentrations than those usually found in previous works, results found in this work were within the ranges normally reported. Global removal efficiencies were calculated, in each case being very variable, even when the same EC and facility were considered. In addition, the SimpleTreat model was tested by comparing simulated and real ibuprofen, diclofenac and erythromycin data. The best agreement was obtained for ibuprofen which was the EC with the highest removal efficiencies. Full article

Lithium-ion batteries are one of the most popular and efficient energy storage devices. In this paper, the characteristics of high-capacity lithium-iron-phosphate batteries during the impulse and long-term operation modes of batteries with different levels of the discharge current are considered. A modified DP-model is proposed. The novelty of the model is the possibility to calculate the activation polarization parameters for different discharge currents. The state of charge is estimated using a high-order polynomial. Based on the developed model, transient processes with rapid load changes and the dependence of the battery voltage on the state of charge were obtained. Here, the model is intended to be used for the design of energy storage systems. The results showed that the DP-model is reliable under the tested conditions and can be used for the considered application. Full article

The poultry meat industry generates about 60 million tons of waste annually. However, such waste can serve as a cheap material source for sustainable liquid fertilizers or biostimulant production. Moreover, its practical potential associated with the circular economy is evident. One of the options for waste feather reprocessing is to use a hydrolysis process, whose operating parameters vary depending on the waste material used. The better the quality of the waste feathers, the less energy is needed; moreover, a higher yield of amino acids and peptides can be achieved. These are the main operational parameters that influence the overall environmental and economic performance of the hydrolysis process. The assessment of process operational environmental aspects confirmed that the environmental impacts of hydrolysate production are highly dependent on the amount of electricity required and its sources. This fact influences the midpoint and the endpoint impacts on the observed environmental impact categories. It also minimizes the pressure associated with fossil resource scarcity and the related impact on climate change. During an economic evaluation of the process, it was found that the option of processing more fine waste, such as CGF, provided a 5% saving in energy costs related to the reduction in the cost per liter of hydrolysate of 4.5%. Finally, a case study experiment confirmed the fertilizing effect of the hydrolysate on pepper plants (biometric parameters, yield). Thus, the hydrolysate produced from the waste feathers can serve as a substitute for nitrate fertilizing, which is commonly drawn from raw fossil materials. Full article

The corrosion process leads to high power consumption, high maintenance costs and the loss of commercial income during downtime in various branches of industry. The proper methods to measure and forecast the corrosion process would help intervene in process production where corrosion is a common phenomenon. Therefore, the main aim of this experimental study is to improve the widely used corrosion monitoring methods with corrosion coupons. As part of this work, the installation for testing corrosion process under controlled conditions and with the application of mild steel coupons is proposed. The measurement concept is to install the coupons in a stream with the corrosion liquid (these conditions should be controlled). The numerical simulations of the fluid flow in the coupon installation were carried out, and the obtained results in the form of a velocity map allowed us to propose the placement of the coupons in the tested installation in such a way that the flowing liquid evenly washed the coupon surface. The developed coupon installation was tested for aggressive corrosive conditions, which were assessed using the water stability indices (Langelier Saturation Index and Ryznar stability index). Moreover, the inductively coupled plasma optical emission spectroscopy analysis characterised the liquid samples from the tested coupon installation. The corrosion process for the applied conditions was defined based on the corrosion rate of the tested coupons. This process was also confirmed by obtaining the Raman spectrum for the used corrosion coupons. The obtained investigation contributes significantly by developing the novel coupon installation and demonstrating the procedure for testing the corrosion process with the application of coupons. This setup and method might be successfully applied for accelerated laboratory tests. Full article

The activated sludge process is the most widespread sewage treatment method. It typically consists of a pretreatment step, followed by a primary settling tank, an aerobic degradation process, and, finally, a secondary settling tank. The secondary effluent is then usually chlorinated and discharged to a water body. Tertiary treatment aims at improving the characteristics of the secondary effluent to facilitate its reuse. In this work, through a literature review of the most prominent tertiary treatment methods, a benchmarking of their technical efficiency, economic feasibility, and environmental impact was carried out. The photo-Fenton method proved to be the most technically efficient process, significantly reducing the microbial load and pharmaceutical content (by 4.9 log and 84%, respectively) of the secondary effluent. Chlorination and UV irradiation exhibited the lowest treatment costs (0.004 EUR/m⁻³) and the lowest global warming potential (0.04 and 0.09 kg CO₂eq. m⁻³, respectively). After all the data were aggregated, a decision-making tool was constructed in the form of a ternary diagram, which indicates the most appropriate tertiary treatment method according to the weight-per-process aspect (technical, economic, and environmental) selected by the user, with chlorination, UV irradiation, ozonation, microalgae cultivation, and constructed wetlands prevailing in the final results. Full article

The concentration of carbon dioxide in the atmosphere has been increasing since immediately after the boom of industrialization. Novel technologies are required for carbon dioxide (CO₂) capture, storage, and its chemical conversion into value-added products. In this study, we present a novel in situ CO₂ utilization method via a hydrogenation process in the presence of nickel tallates during steam-based enhanced oil recovery. The light n-alkanes are the preferred products of in situ catalytic hydrogenation of CO₂ due to their effective solubility, viscosity-reducing capacity, and hydrogen-donating capacity. A nickel tallate was evaluated for its carbon dioxide hydrogenation and oil-upgrading performance at 300 °C. The results showed that the content of saturated and aromatic fractions increased, while the content of heavier fragments decreased. Moreover, the relative content of normal C10–C20 alkanes doubled after the catalytic hydrogenation of CO₂. Despite the noncatalytic hydrogenation of CO₂, the viscosity was altered from 3309 mPa^.s to 1775 mPa^.s at a shear rate of 0.66 s⁻¹. The addition of the catalyst further contributed to the reduction of the viscosity, down to 1167 mPa^.s at the same shear rate. Thus, in situ catalytic hydrogenation of CO₂ not only significantly reduces the concentration of anthropogenic carbon dioxide gas in the atmosphere, but it also enhances the oil-recovery factor by improving the quality of the upgraded crude oil and its mobility. Full article

Elderberries are appreciated for their antioxidant properties. Sambucus nigra L. is an extremely abundant plant in the wild flora of Romania, but it is underutilized. Elderberry is used in modern and traditional medicine due to the complex chemical composition of the fruit. The content of phenolic compounds is high (516–8974 mg/100 g DW), of which the most abundant are anthocyanins. Phenolic compounds are known for their beneficial effects on the body. Numerous studies have demonstrated the antioxidant capacity, antibacterial, antiviral, antidiabetic, and anticancer properties of the fruit. It is considered that most of the therapeutic properties of elderberries can be correlated with the antioxidant activity they have. S. nigra fruits are also used in the food industry. Some studies have shown that the therapeutic properties of elderberries can also be found in the products obtained from them. Therefore, this review aimed to describe the chemical composition of elderberries and products obtained from them, the positive effects on the body, and the methods by which the bioactive compounds can be extracted from the fruits and analyzed. This manuscript is useful for extraction optimization and characterization in order to valorize new functional foods, food supplements, and also in new pharmaceutical products. Full article

Alachlor [2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl]acetamide] is a chloroacetanilide herbicide and has been widely used as a selective pre-emergent and post-emergent herbicide to control weeds and grass. Due to its wide usage, direct application on the ground, high solubility in water, and moderate persistence, alachlor and its metabolites have been detected in various environments. Therefore, there is an increasing concern about the environmental fate of alachlor and its metabolites. Microbial biodegradation is a main method of removal of alachlor in the natural environment. In this study, we isolated new alachlor degrading bacterium and proposed a novel alachlor-degrading pathway. The alachlor-degrading bacterial strain, GC-A6, was identified as Acinetobacter sp. using 16S rRNA gene sequence analysis. Acinetobacter sp. GC-A6 utilized alachlor as its sole carbon source and degraded 100 mg L⁻¹ of alachlor within 48 h, which was the highest alachlor degradation efficiency. The degradation pathway of alachlor was studied using GC-MS analysis. Alachlor was initially degraded to 2-chloro-N-(2,6-diethylphenyl) acetamide, which was further degraded to 2,6-diethylaniline and 7-ethylindoline, respectively. 2,6-Diethylaniline was transformed into N-(2,6-diethylphenyl) formamide. N-(2,6-diethylphenyl) formamide was a first-reported intermediate during the degrading pathway of alachlor by single isolate. Full article

The research aims to produce, model, and optimise the mechanical properties of novel composite material through a structured multidisciplinary approach. The primary objective is to combine materials science, mechanical engineering, and statistical concepts to ensure Design for Manufacturability (DFM) from the industrial perspective. More specifically, the article is intended to determine the optimal mixture components and predictive model of Al-Si alloy with Al₂O₃ by accommodating multi-responses that enable DFM. The study adopted ASTM standards to prepare and test the novel composite material. Additionally, the Mixture Design of Experiment (DOE) approach was used to design the experimentation and subsequent analysis. In addition, microstructural images, Cox Response Trace plot, and Response Optimiser plot are effectively utilised to draw robust inferences. For multi-response modelling and optimisation, the composite material’s mechanical properties, like impact strength, hardness, density, and tensile strength, are considered. The study determines that innovative composite material will yield better results when Al-Alloy is 94.65 wt% and Al₂O₃ is 5.35 wt% from a multi-responses perspective. Further, it provides predictive models with a high level of predictability. Besides, the research shows that novel composite material has better mechanical properties from a practical perspective. The article not only provides the mechanical properties of a new class of material but also shows the effective utilisation of material science and statistical concepts to develop the novel material in a structured manner. This composite material can be used as a replacement for various parts of automobiles and aircraft. Additionally, researchers can use the article’s modelling and optimisation approach as a paradigm to create durable composite materials. Full article

Photodynamic therapy and photoacoustic (PA) imaging are emerging therapeutic modalities for the diagnosis and treatment of various types of cancer or other diseases. In this study, the second-generation photosensitizer Chlorin e6 was prepared on a pilot scale by using the rapid, simple, and green synthetic method as compared to a conventional protocol. In the modified method, the extraction/reaction time and volume of solvents were significantly reduced. The dark and photodynamic cytotoxicity of Ce6 was measured against B16F10 melanoma cell line. Ce6 did not affect cancer cells in the dark up to 192 µM, ensuring their safety in the absence of light. After PDT, it displayed significant cytotoxicity at lower concentrations (IC50: 18.9 µM). For in vivo study, B16F10 allograft mice were treated with Ce6 at 2.5 mg/kg and then exposed to red light (660 nm) after 3 h. The Ce6-PDT caused the inhibition of tumor growth. Furthermore, Ce6 was also used as a photoacoustic imaging agent in ICR mice to visualize the internal organs. Therefore, this study provides valuable information about Ce6-PDT as a promising strategy for anti-cancer therapy as well as visualization of internal organs without surgery or x-rays. Full article

Rough processing of iron ore employs dry methods which means that equipment is tuned to process large particles, but fine magnetic material less than a few tenths of a millimeter in size is not separated as efficiently. The relevance of this study is determined by the fact that dry beneficiation waste contains recoverable iron-bearing magnetite of commercial value. Commercial justification of waste beneficiation is associated with mining and grinding costs that are already included in the prime cost of the commercial concentrate. The future of tailings retreatment prospects depends on technology and efficiency of the employed equipment, the development of which is the subject of this paper. At first stage, fine iron is recovered by air sizing, with pitched curtain air classifiers embedding simple design and high performance. Powder materials were magnetically separated by a manufactured drum-type separator in which, to increase the separation efficiency, the process was performed at increased drum rotation speeds using $Nd$-$Fe$-B magnets and a drum made of electrically non-conductive materials. The separator performance was determined for various rotation speeds of the drum. Research has proven that a multi-stage magnetic separation with a consequent increase in drum rpm is reasonable. A new cascade separator was manufactured and tested for this purpose. It is shown that iron-containing ore tailings beneficiation is optimal without any additional grinding. Full article

Modifier Adaptation (MA) is a method of real-time optimization (RTO) which modifies a single model to match the first order properties of the plant. Known uncertainties in the parameters of this model are discarded in favor of real-time measurements, but they can be used to quantify the mismatch between the plant and model. Using multi-model methods increases the computation time, but can improve rate of convergence of the RTO scheme. This article proposes a framework, known as multiple solution modifier adaptation (MSMA), which produces several models which are all modified in the same way as standard MA, each producing a potential solution to be applied to the plant. From this framework, three recommended schemes are proposed on how to select the operating point to be applied to the plant: (1) Selecting the solution based off the modifiers; (2) Selecting the mean solution from convex models; (3) Selecting the closest solution to the current operating point. Each of these methods have different advantages, including limiting the increase in computational complexity and improving the model adequacy conditions of the scheme. These recommended schemes are shown on three different case studies of varying complexity with all three schemes showing improvements over standard MA. Full article

Turbulent emulsification is an important unit operation in chemical engineering. Due to its high energy cost, there is substantial interest in increasing the fundamental understanding of drop breakup in these devices, e.g., for optimization. In this study, numerical breakup experiments are used to study turbulent fragmentation of viscous drops, under conditions similar to emulsification devices such as high-pressure homogenizers and rotor-stator mixers. The drop diameter was kept larger than the Kolmogorov length scale (i.e., turbulent inertial breakup). When varying the Weber number (We) and the disperse-to-continuous phase viscosity ratio in a range applicable to emulsification, three distinct breakup morphologies are identified: sheet breakup (large We and/or low viscosity ratio), thread breakup (intermediary We and viscosity ratio > 5), and bulb breakup (low We). The number and size of resulting fragments differ between these three morphologies. Moreover, results also confirm previous findings showing drops with different We differing in how they attenuate the surrounding turbulent flow. This can create ‘exclaves’ in the phase space, i.e., narrow We-intervals, where drops with lower We break and drops with higher We do not (due to the latter attenuating the surrounding turbulence stresses more). Full article

Renewable energy is a key technology for achieving carbon-free energy transitions, and solar power systems are one of the most reliable resources for achieving this. Solar power systems have a simple structure and are inexpensive. However, depending on the input irradiance, the existing maximum output control algorithm (P&O) has disadvantages due to its slow transient response and steady-state vibration. Therefore, in this paper, we propose a maximum output control algorithm based on a deep learning algorithm that can predict the input irradiance. This can achieve a quick transient response and steady-state stability. The proposed method predicts the irradiance based on the output voltage/current and power of the photovoltaic (PV) system and calculates the duty ratio that can accurately follow the maximum output point according to the irradiance. The deep learning model applied in this study was trained based on the experimental results using a 100 W PV panel, and the performance of the proposed algorithm was verified by comparing its performance with that of the conventional algorithm under various input irradiance conditions. The proposed algorithm exhibits a maximum efficiency increase of 11.24% under the same input conditions as those of the existing algorithms. Full article

Biosolids generated as byproducts of wastewater treatment processes are widely used as fertilizer supplements to improve soil condition and ultimately agricultural products yields and quality. However, biosolids may contain toxic compounds, i.e., per- and polyfluoroalkyl substances (PFAS), which can end up in soils, groundwater, and surface water, causing adverse environmental and health effects. The purpose of this study was to investigate the application of High-Temperature Pyrolysis (HTP) treatment for biosolids management, and its efficacy in eliminating PFAS from the solid fraction. Biosolid samples were pyrolyzed at two different temperatures, 500 and 700 °C, in a continuous bench-scale pyrolysis unit. The major finding is that the treatment process at higher pyrolysis temperatures can remarkably reduce or eliminate the level of PFAS (by ~97–100 wt%) in the resulting biochar samples. Full article

The most widely applied methods to unlock heavy oil and natural bitumen resources in the world are still based on steam injection techniques. Improving the efficiency of hydrothermal processes poses a great challenge. The co-injection of various additives is practiced to lower the steam-to-oil ratio (SOR), viscosity alteration and to improve heavy oil properties. Organic solvents, non-condensable gases, air and surfactants are the preferred chemicals to be combined with steam. This study provides an investigation of the surfactant-assisted hydrothermal upgrading of heavy oil at 200 °C. The thermal stability and salt resistivity of two non-ionic surfactants (SA–3 and Biolub Green) were investigated. Moreover, the improved performance of the surfactants was established by performing an SARA analysis, elemental analysis, FT-IR spectroscopy, and EPR analysis, and by studying the viscosity reduction degree. The experimental results showed that surfactants lead to the in-depth destructive hydrogenation of the high-molecular components of heavy oil such as resins and asphaltenes. However, the content of light fractions increased. According to the results of the elemental analysis, the surfactants assist in the hydrodesulphurization of heavy oil. Overall, the physical and chemical consequences of hydrothermal upgrading in the presence of surfactants led to the irreversible viscosity reduction of heavy oil. Full article

Industry 4.0 is the latest technological age, in which recent technological developments are being integrated within industrial systems. Consequently, maintenance management of current industrial manufacturing systems is affected by the emergence of the technologies and features of Industry 4.0. This study aimed to conduct a comprehensive literature review to understand how Industry 4.0 technologies and features affect the various functions of maintenance management systems. The reviewing process was initiated by examining the most recent related literature in three different databases. In total, 54 articles were classified into three research categories. Then, the integration of the main functions and components of the adopted maintenance management model and the Industry 4.0 features and technologies were aligned, focusing on the driving force of predictive maintenance. The analysis focused mainly on the technical aspects of the integration process, including integration concepts and integration-assisting tools, identifying the main applications and highlighting the challenges identified in the analysed literature. The key findings were that the main functions of maintenance management systems are significantly influenced by different Industry 4.0 technologies, mainly artificial intelligence–machine learning, CPS, IoT, big data, augmented reality, and cloud computing, in terms of successful integration. Consequently, the overall system implied tangible improvements through the involvement of different Industry 4.0 features which promote real-time condition monitoring, enable data management and curation, increase coordination between various maintenance tasks, facilitate supervision through remote maintenance applications, and, overall, improve operations and productivity, reduce unplanned shutdowns and, as a result, reduce the associated costs. To provide research directions, examples, and methodologies for integrating the various maintenance management system functions with the cutting-edge Industry 4.0 technologies and features based on real and practical cases present in the reviewed literature, the review’s findings are comprehensively categorised and summarised. Full article

In the range of 800–1200 K, both experiments and kinetic modeling demonstrate a significant difference in the dependence of the ignition delay time of methane and hydrogen on pressure and temperature, with the complex influence of these parameters on the autoignition delay time of methane–hydrogen–air mixtures. In connection with the prospects for the widespread use of methane–hydrogen mixtures in energy production and transport, a detailed analysis of their ignition at temperatures below 1000 K, the most important region from the point of view of their practical application, is carried out. It is shown that such a complex behavior is associated with the transition in this temperature range from low-temperature mechanisms of oxidation of both methane and hydrogen, in which peroxide radicals and molecules play a decisive role, to high-temperature mechanisms of their oxidation, in which simpler radicals dominate. A kinetic interpretation of the processes occurring in this case is proposed. Full article

The separation of polyethylene glycols (PEGs) into single homologs by reversed-phase chromatography is investigated experimentally and theoretically. The used core–shell column is shown to achieve the baseline separation of PEG homologs up to molar weights of at least 5000 g/mol. A detailed study is performed elucidating the role of the operating conditions, including the temperature, eluent composition, and degree of polymerization of the polymer. Applying Martin’s rule yields a simple model for retention times that holds for a wide range of conditions. In combination with relations for column efficiency, the role of the operating conditions is discussed, and separations are predicted for analytical-scale chromatography. Finally, the approach is included in an efficient process model based on discrete convolution, which is demonstrated to predict with high accuracy also advanced operating modes with arbitrary injection profiles. Full article

Gasification is a promising and attractive thermochemical method for biomass-to-energy conversion, with fluidized bed reactors being one of the best options for large-scale operations. Olive residues in particular are potentially excellent candidate biomass fuels in the Mediterranean area, due to the region’s increased capacity in olive oil production. Herein, the gasification experiments of olive kernels in a 2 MWth air-blown, bubbling fluidized bed reactor located at CENER’s facilities (BIO2C) in Navarra, Spain are presented. Even though technical issues were demonstrated due to the operation of the plant with a high-density biomass fuel and given the scale of the process, a quasi-steady-state and isothermal 12 h operation at an equivalence ratio of 0.25 ± 0.03 was attained. Given the satisfactory experimental results, an Aspen Plus simulation model of the process was also attempted. Notably, the proposed methodology agrees well with the experimental results and can be regarded as a starting point in future studies examining the gasification of relevant biomass in a MW-scale unit. Next, the effect of equivalence ratio and residual biomass moisture content were also evaluated, with the scope of designing future experiments that require minor modifications in the already existing apparatus. Finally, a syngas utilization route through the provision of energy for district heating purposes in the nearby village of Aoiz was proposed. Full article

The objective of this work was to determine the optimal conditions for the electrooxidation treatment in order to decolourise the effluents that contain reactive dyes. According to the results, when Na₂SO₄ is used as an electrolyte, the decolouration reactions follow first-order kinetics. However, when NaCl is present in the effluent, the first-order kinetics is stabilised after applying a minimal electric current value. The models obtained from the results show that the higher the concentration of NaCl, the lower the energy consumption. On the other hand, an increase in dye concentration leads to an increase in electrical consumption. In relation to the pH, the results show that it is not a key factor in the decolouration efficiency. Finally, the obtained model was applied to two real effluents. The feasibility of individually treating the effluents from the dyeing process and those from the subsequent wash-off process was evaluated. From an industrial application point of view, it is recommended to mix both effluents before treatment, especially when the dye concentration is high. Full article

A series of numerical simulations were performed to study the discharge coefficient based on the geometric parameters of a stepped labyrinth seal that sealed the secondary flow path of a gas turbine. In contrast with straight-through seals, stepped labyrinth seals introduce additional geometrical parameters related to the steps. In this study, three shape variables were observed: step height (SH), position, and cavity width (CW). The sensitivity to the leakage flow of the shape variable in the stepped labyrinth seal was analyzed. The mechanism for improving the sealing performance of stepped labyrinth seals was investigated. The results indicated that the stepped labyrinth seal exhibited up to 17.9% higher leakage-suppression performance than the straight labyrinth seal. Seals with large discharge coefficients had a large vena contracta upstream of each tooth structure and a rapidly accelerated axial velocity in the radial direction. We could observe that the discharge coefficient changed according to the flow field in the cavity. The wall shear stress was sensitive to the SH but not to the CW or step position. Full article

This study proposes a recognition method based on symmetrized dot pattern (SDP) analysis and convolutional neural network (CNN) for rapid and accurate diagnosis of insulation defect problems by detecting the partial discharge (PD) signals of XLPE power cables. First, a normal and three power cable models with different insulation defects are built. The PD signals resulting from power cable insulation defects are measured. The frequency and amplitude variations of PD signals from different defects are reflected by comprehensible images using the proposed SDP analysis method. The features of different power cable defects are presented. Finally, the feature image is trained and identified by CNN to achieve a power cable insulation fault diagnosis system. The experimental results show that the proposed method could accurately diagnose the fault types of power cable insulation defects with a recognition accuracy of 98%. The proposed method is characterized by a short detection time and high diagnostic accuracy. It can effectively detect the power cable PD to identify the fault type of the insulation defect. Full article

Despite intensive research over the last three decades, it has not yet been possible to bring an effective vaccine against human immunodeficiency virus (HIV) and the resulting acquired immunodeficiency syndrome (AIDS) to market. Virus-like particles (VLP) are a promising approach for efficient and effective vaccination and could play an important role in the fight against HIV. For example, HEK293 (human embryo kidney) cells can be used to produce virus-like particles. In this context, given the quality-by-design (QbD) concept for manufacturing, a digital twin is of great importance for the production of HIV-Gag-formed VLPs. In this work, a dynamic metabolic model for the production of HIV-Gag VLPs was developed and validated. The model can represent the VLP production as well as the consumption or formation of all important substrates and metabolites. Thus, in combination with already described process analytical technology (PAT) methods, the final step towards the implementation of a digital twin for process development and design, as well as process automation, was completed. Full article

The paper investigates the physicochemical regularities (kinetics and isotherm) of phosphorus and beryllium recovery by sorbents based on polyacrylonitrile (PAN) fiber and Fe(OH)₃ obtained by various methods: PAN or pre-hydrolyzed PAN with precipitation of FeCl₃ with ammonia, using ready-made or electrochemically generated Na₂FeO₄, pre-hydrolyzed PAN treated with an alkaline solution of Na₂FeO₄, as well as their comparison with granular aluminum oxide. The Langmuir, Freudlich and Dubinin–Radushkevich models show high performance of materials for sorption of stable P and Be used as tracers for the release of ⁷Be, ³²P, and ³³P from seawater. The obtained kinetic data are processed using kinetic models of intraparticle diffusion and the pseudo-first-order, pseudo-second-order, and Elovich models. Optimal conditions for obtaining sorbents are established, namely, the effect of NaOH concentration at the stages of preparation on the properties of sorbents based on the PAN fiber and Fe(OH)₃ obtained by various methods. Full article

As the third most plentiful biopolymer after other lignocellulosic derivates such as cellulose and hemicellulose, lignin carries abundant potential as a substitute for petroleum-based products. However, the efficient, practical, value-added product valorization of lignin remains quite challenging. Although several studies have reviewed the valorization of lignin by microorganisms, this present review covers recent studies on the valorization of lignin by employing yeast to obtain products such as single-cell oils (SCOs), enzymes, and other chemical compounds. The use of yeasts has been found to be suitable for the biological conversion of lignin and might provide new insights for future research to develop a yeast strain for lignin to produce other valuable chemical compounds. Full article

This study investigated calcium sulfate and chitosan on the textural modification and microstructure of tofu made from lentils. The addition of varying amounts of calcium sulfate (0–12 mM) and chitosan (0–1.0%) into lentil milk could affect the gel properties of lentil-based tofu. The gel properties, including the hardness and cohesiveness, of lentil-based tofu significantly increased with the addition of 12 mM calcium sulfate, exhibiting a slightly discontinuous network structure and a slightly regular pore network. However, the gel properties including hardness and cohesiveness significantly decreased with the addition of 1.0% chitosan, presenting a slightly continuous network structure with pores. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed that the aggregation of the vicilin, legumin acidic unit and legumin basic unit proteins in lentil milk was induced both by 12 mM calcium sulfate and 1.0% chitosan. Our results suggested that calcium sulfate and chitosan could affect the gel properties, such as hardness and cohesiveness, of lentil-based tofu. Therefore, calcium sulfate and chitosan can be used as practical food additives for the development of texture-modified lentil-based tofu. Full article

Peaberry coffee is the result of a natural mutation of coffee beans, and they make up only about 5–7% of coffee crops. A typical coffee cherry contains two seeds that are developed against each other, resulting in the distinctive half-rounded shape of coffee beans. However, failing to fertilize both ovules of one of the seeds or failure in endosperm development can cause only one of the seeds to develop, resulting in smaller, denser beans with a more domed shape. Peaberry coffees are said to be sweeter, lighter, and more flavorful since the peaberry beans receive all nutrients from the coffee cherry. Due to its exclusive nature, the chemical characteristic of peaberry coffee is not well understood. This study explores the acidities and antioxidant activity of peaberry coffee sourced from multiple regions. Total antioxidant capacity, total caffeoylquinic acid (CQA), total caffeine concentration, and pH levels were evaluated for peaberry coffee extracts prepared by cold and hot brewing methods. Little correlation between antioxidant activity and the concentrations of caffeine and CQA in peaberry beans was shown. Six methods were performed for the characterization of total antioxidant capacity including cyclic voltammetry, ABTS assay, and FRAP assay. Peaberry bean extract demonstrated higher average total caffeine concentrations compared to traditional coffee bean extracts. Full article

The effect of quasi-exponentially decreasing film thicknesses of thin poly-para-xylylene (PPX-N) coatings inside narrow tubes or micro scaled gaps is well known and has been discussed by many authors since the late 1970s. However, for technical applications it is often necessary to provide a longitudinal homogeneous film thickness to ensure the constant properties that are required. In a previous work, it was shown, in principle and for the first time, that a temperature gradient along the tube will effectively counteract the longitudinal decreasing film thickness of the PPX-N coating of the interior wall of a capillary. Therefore, this effect is discussed in theory and the provided model is verified by experiments. Our prediction of a required sticking coefficient curve yields experimentally measured homogeneous film thicknesses and shows a good agreement with the given prognosis. Further, it is shown in theory that there is a maximum achievable homogeneous film thickness in the tube in comparison to a blank surface, which can be understood as a coating efficiency for this type of deposition. Full article

Sol–gel-based carbon xerogels possess very promising properties for pollution abatement, using processes that associate adsorption and on-site electrochemical oxidation. However, combining a high exterior surface area (for efficient diffusion) and a monolithic shape (necessary for electrochemical processes) poses challenges. In this work, the shape of monolithic carbon xerogels was contrived by the use of 3D-printed molds. Several parameters were optimized: the choice of mold design, the choice of plastic, the 3D printer parameters, the solvent, and the process of dissolving the plastic. A design combining fine sticks and plates made of ABS was printed; a sol–gel carbon xerogel monolith was synthesized in it, and the mold was removed by using a combination of acetone and pyrolysis. Dissolving the plastic could be carried out by placing the material on a metallic net and leaving the dissolved ABS to settle. The resulting carbon material exhibits a high exterior surface area and good strength, leading to potential uses in the aforementioned process. The research shows that 3D printing is an efficient method of parameter optimization in pre-industrialization research, thanks to its flexibility, low cost, and ease of use. Full article

Spice plants are popularly used as ingredients in food products. Promoting healthy eating, paying attention to the quality of products, means that organic and self-produced ingredients, whose origin and growing conditions are known, are gaining popularity. The study determined the concentration of mercury (Hg) in popular leafy spice plants: peppermint (Mentha piperita), common basil (Ocimum basilicum), lovage (Levisticum officinale) and parsley (Petroselinum crispum). Self-grown spices and ready-made commercial products were selected for the study. The Hg content in the test samples was determined by the AAS method (AMA 254, Altec, Praha, Czech Republic). The range of Hg content in the tested spice samples ranged from 1.20 to 17.35 µg/kg, on average 6.95 µgHg/kg. The highest concentration of Hg was recorded in the peppermint, 9.39 µg/kg. In plants grown independently, the concentration of Hg was statistically significantly higher than in commercial products purchased in a store. There were no differences in the concentration of Hg in organic and non-organic spices. Commercial spices defined by producers as organic products did not differ statistically significantly in the level of Hg content from non-organic products. Full article

Gluten-free products made from naturally gluten-free raw materials have an inferior taste and can cause deficiencies in various nutrients, especially non-starch polysaccharides. To address this problem, scientists are searching for new strategies to eliminate harmful gluten from wheat, rye, and barley and to produce balanced products with good organoleptic properties. This study evaluated the possibility of hydrolysing gluten in wheat bran, a by-product obtained after the dry fractionation of wheat, using plant enzymes. The gluten content of wheat bran after treatment with papain, bromelain, and their combination under different hydrolysis conditions was investigated. The amount of gluten was determined using an enzyme-linked immunosorbent assay ELISA R5 and the reduction in immunogenic gliadins was analysed using high-performance reverse phase liquid chromatography. The results of the study showed that 4 h hydrolysis with bromelain and papain reduced the levels of gluten immunogenic compounds in bran from 58,650.00 to 2588.20–3544.50 mg/kg; however, they did not reach the gluten-free limit. A higher hydrolysis efficiency of 95.59% was observed after treatment with papain, while the combination of both enzymes and bromelain alone were less effective. The results presented in this article will be helpful to other researchers and manufacturers of wheat-based products when selecting methods to reduce gluten immunogenicity and contribute to the development of sustainable technologies. Full article

Consistency in gas flow behavior under various operating conditions is expected for uniform cutting performance in the thermal cutting process. The slope of the cut front in the kerf slot of a sample cutting material varies with the operating condition which affects the gas flow pattern. Therefore, how the nozzle exit diameter and the slope of the cut front effects gas flow behavior has been studied using the Reynolds averaged Navier–Stokes (RANS) based k–ω turbulence model. Convergent–straight-type nozzles with exit diameters φ_exit of 1.5 mm, 2 mm and 2.5 mm were used to study the flow patterns through the kerf slots of variable cut front slopes. The numerical simulation results were then compared with the results obtained from the Schlieren experiments. In addition, image processing was performed in the Schlieren images for clear visualization and precise comparison of the numerical and experimental data. The results confirm that a nozzle with an exit diameter of 2 mm shows a higher consistency in flow behavior in variable operating conditions. Full article

Large eddy simulations were performed for the conjugate heat transfer in a ribbed channel with a geometry, that mimics the internal cooling passage of a gas turbine, using 566, 100, 10, and 1 as the solid and fluid thermal conductivity ratios (K*) and 30,000, 7000 (turbulent flow), and 1000 (laminar flow) as the Reynolds numbers. A fully coupled simulation was conducted using the immersed boundary method (IBM) and a dynamic sub-grid-scale (SGS) model. In pure convection, a decrease in the Reynolds number from 30,000 to 7000 increased the heat transfer on the channel wall by 5% but decreased that on the rib by 20%. When K* > 10, the Reynolds number effect is stronger in the rib than in the wall. In the laminar flow, the effect of conduction appears at a low K*, and the heat transfer promotion is poor in the typical ribbed channel geometry. In the turbulent flow, if K* ≥ 100, then a heat transfer promotion is expected in the ribbed channel even at a low Reynolds number. For K* < 10, the thermal performance in the turbulent flow is worse than that in the laminar flow, and thus, no rib effect is expected. Full article

Wild bitter gourd extracts, such as saponins, polysaccharides, and peptides, could be used to adjust blood sugar. The objective of this research was to explore the use of high pressure processing (HPP) for sterilization and acceleration of enzyme hydrolysis in the ultrasonic preparation of peptide extracts from wild bitter gourd. The results showed that the wild bitter gourd powder could be extracted via ultrasonic processing with water at 70 °C for only 20 min with a solid to liquid ratio of 1:20 to obtain the total protein content of 1.514 mg/g. The two sterilization methods for wild bitter gourd extract treated with papaya enzyme—for 2 h in the traditional autoclave at 121 °C for 15 min, or under HPP 300 MPa for 5 min—showed no significant effect on protein content, and both sterilization methods were effective. However, the extract sterilized with HPP had a significantly higher ability to scavenge DPPH free radicals. In addition, HPP (300 MPa for 5 min), combined with papaya enzyme to hydrolyze the wild bitter gourd extract, simultaneously pasteurized the extract and acquired the peptides from the wild bitter gourd extract Therefore, the ultrasonic extraction of wild bitter gourd, combined with HPP and enzyme hydrolysis, could greatly shorten the operation time (to only 5 min) for extracting the active peptides. Full article

A theory-based prediction method was used to estimate the friction factor and heat transfer rate in the turbulent flow of a helically coiled tube. The secondary flow produced by a centrifugal force improves heat and mass transfer; therefore, spiral coil pipes are widely used in a variety of industrial applications. The law of the wall and the Reynolds analogy, which states that momentum transfer in a turbulent flow is equivalent to heat transfer, were used in this theoretical method. The logarithmic law was used to characterize the velocity profile in the turbulence-dominated region, and the local wall shear stress variation throughout the circumference of the helical tube wall was considered. The friction factor and heat transfer in the turbulent flow of the helically coiled tube were accurately predicted by the model. Using the Reynolds analogy, the local Nusselt number in the circumferential direction of the helical tube wall was determined. The effect of decreasing local heat transfer within the tube while increasing heat transfer outside the tube was quantified. The analogy between the momentum flux and the heat flux in the turbulent flow of the straight tube was also proven to be applicable to the spiral tube. Full article

The possibilities of the action of uneven air flows on the grain material in the separating channels are still not used enough. The reason for this is the insufficient knowledge of the processes of interaction of the components of the grain material with an uneven air flow. The purpose of the research is to increase the efficiency of grain material separation according to aerodynamic properties by purposefully changing the diagram of air velocities in the channel sections using the actions of lateral and aerodynamic forces. The separation efficiency of grain material components was determined by trajectory analysis. The different geometry of the pneumatic separation channel was studied. The study of the distribution of air velocity and air pressure vectors in a vertical annular channel was carried out using the FlowVision software. It has been established that a change in the air velocity diagram can be implemented both by changing the geometric parameters of the channel and by additional distributed air supply through the perforation in the side walls of the pneumatic channel. Based on the analysis of the velocity field, an improved scheme of a pneumatic gravitational separator is proposed for separating grain material into three fractions according to aerodynamic characteristics. Full article

Sensor acquired signal has been a fundamental measure in rotary machinery condition monitoring (CM) to enhance system reliability and stability. Inappropriate sensor mounting can lead to loss of fault-related information and generate false alarms in industrial systems. To ensure reliable system operation, in this paper we investigate a system’s multiple degrees-of-freedom (DOF) using the finite element method (FEM) to find the optimum sensor mounting position. An appropriate sensor position is obtained by the highest degree of deformation in FEM modal analysis. The effectiveness of the proper sensor mounting position was compared with two other sensor mounting points, which were selected arbitrarily. To validate the effectiveness of this method we considered a gear-actuator test bench, where the sensors were mounted in the same place as the FEM simulation. Vibration data were acquired through these sensors for different health states of the system and failure patterns were recognized using an artificial neural network (ANN) model. An ANN model shows that the optimum sensor mounting point found in FEM has the highest accuracy, compared to other mounting points. A hybrid CM framework, combining the physics-based and data-driven approaches, provides robust fault detection and identification analysis of the gear-actuator system. Full article

Solid biofuels produced from torrefaction have improved coal-like properties in comparison to raw biofuels, yet ensuring uniform product quality is still a challenge. In this study, downstream torrefaction of wood pellets was performed at temperatures between 200 and 270 °C in a rotary kiln reactor to understand the effect of torrefaction temperature on product quality. The torrefied solid biofuel was compared with dedicated fuel properties defined in ISO/TS 17225-8:2016-12. Based on the results, the optimal temperature for downstream torrefaction was found at temperatures of 230 and 250 °C. Above this temperature, the effect of bulk density superimposes not only the increased net calorific value but also values for mechanical durability, amount of fines, and bulk density of the solid biofuel, which were below the thresholds of the fuel standard. Moreover, increasing process temperatures caused higher heavy metal concentrations in torrefied pellets. The composition of condensable and non-condensable fractions of the torr-gas substantially increased between temperatures of 230 and 250 °C and remained on a similar level at higher temperatures. Thus, the utilization of torr-gas for energy recovery purposes and as a precursor for the recovery of valuable chemicals should be balanced with the quality of the solid biofuel in the aforementioned range of torrefaction temperatures to enable the utilization of torrefaction products at further steps. Full article

When a liquid flows, it has an internal resistance to flow. Viscosity is the property that measures this resistance, which is a fundamental characteristic parameter of liquids. The monitoring of viscosity is essential for quality control in many industrial areas, such as the pharmaceutical, chemical, and energy-related industries. Several instruments measure the viscosity of a liquid, the most used being the capillary viscometers. These instruments are complex, associated with high cost and expensive prices. This represents a challenge in several industries, where accurate viscosity knowledge is essential in designing various industrial equipment and processes. Using image processing and machine learning algorithms is a promising alternative to the current measurement methods. This work aims to extract characteristic information from videos of droplets of different samples using image processing algorithms. An Artificial Neural Network model utilizes the extracted characteristics to classify the droplets in the correct category, which is correlated with the viscosity of the sample. Different solutions samples were created using different ratios of Water and PVP (Polyvinylpyrrolidone) and videos of their droplets were taken and processed. It was found that for water-PVP solutions, the proposed ANN model was able to successfully classify the droplets using the data extracted from the videos with high accuracy. The results imply that the ANN model can recognize the features that affect the viscosity values. Full article

Acinetobacter baumannii is a prominent emerging pathogen responsible for a variety of hospital-acquired infections. It can contaminate inanimate surfaces and survive in harsh environmental conditions for prolonged periods of time in the form of biofilm. Biofilm is difficult to remove with only one method of disinfection, so combined disinfection methods and biocidal active substances are needed for biofilm eradication. Additionally, having in mind ecological demands, legislators are more prone using fewer toxic substances for disinfection that produce less solid waste and hazardous disinfection byproducts. Gaseous ozone and citric acid are natural biocidal compounds, and the purpose of this study was to determine their combined biocidal effects on A. baumannii biofilm formed on ceramics and polystyrene. Twenty-four-hour A. baumannii biofilm formed on ceramic tiles and polystyrene was exposed to different combinations of disinfection protocols with 25 ppm of gaseous ozone for 1 h exposure time and 15% citric acid for 10 min exposure. The total number of bacteria was counted afterwards and expressed as CFU/cm². The determined disinfection protocols of A. baumannii biofilm with combined citric acid and gaseous ozone caused reduction of 2.8 to 5.89 log₁₀ CFU (99.99% inhibition rate) of total viable bacteria for each method, with the citric acid–ozone–citric acid disinfection protocol being most successful in eradication of viable bacteria on both ceramics and polystyrene. In conclusion, gaseous ozone and citric acid showed good combined biocidal effects on A. baumannii biofilm and successfully reduced early A. baumannii biofilm from ceramic and polystyrene surfaces. The given combination of active substances can be a good option for eco-friendly disinfection of hospital inanimate surfaces from A. baumannii biofilm contamination with prior mechanical cleaning. Full article

Carbon-reinforced concrete (CRC) has the potential to play a pivotal role in optimizing the built environment and has therefore been experiencing a wave of research and development in the construction industry in recent years. The production of carbon fibers for CRC is energy-intensive, prompting the need to explore circular economy approaches (e.g., recycling at the End-of-Life (EoL)) to optimize the environmental performance of this material. Underdeveloped processes and a resulting lack of primary data regarding the recycling of CRC have hampered a comprehensive sustainability assessment of the novel composite building material. The novelty of this article is the detailed presentation of possible EoL scenarios for CRC and the detailed determination of the respective environmental impacts. This study aims to model EoL options within a Life Cycle Assessment (LCA), focusing on the EoL stage based on ISO 14040/44 using the GaBi ts 10.5.1.124 software and the CML2001 (2016) methodology. The practical relevance of the study lies in the early consideration of the entire life cycle of new materials, such as CRC, already in the design phase. Furthermore, the EoL can have relevant impacts on the environment, and due to an increasing significance of sustainability aspects, this LCA clarifies first approaches for the future of the construction sector in quantitative statements (e.g., CO₂ emissions). All data are literature-based and are explained in detail and calculated for our case study with the functional unit of one kilogram of re-usable material (reusable and fully usable “raw” material for further use/ development) from a double wall. The impact assessment was calculated for 11 midpoint categories and related indicators, although the main focus was on Global Warming Potential (GWP). It was found that the highest-quality recycled options for CRC arise when the individual fractions (concrete matrix and carbon fibers) are first broken up, separated and then individually processed. This study focused mainly on the processing of the carbon fibers contained in CRC, for which pyrolysis and mechanical recycling have the strongest potential for industrial application. For the demolition and separation of both the concrete and the carbon fiber fractions, the conventional transport from the demolition site to the stationary processing plant proved to be the main driver of the GWP (1.4 × 10⁻³ kg CO₂e). In the subsequent processing of the carbon fibers, pyrolysis showed a higher GWP (9.7 × 10⁻³ kg CO₂e) than mechanical recycling (3.1 × 10⁻⁴ kg CO₂e). In addition, the production of one m³ of concrete (C30/37) was compared to a primary raw material concrete fraction. Concrete can be successfully used as a substitute material for the gravel present in the C30/37 concrete. The use of recycled parts in concrete (originating from the concrete used in carbon-reinforced concrete) as a substitute for primary gravel showed a savings of 6.9 kg CO₂e per m³ of primary concrete, corresponding to a reduction of 22.5%. The results show that the mechanical recycling of carbon fibers is overall the route with the lowest energy input and emissions. However, compared to pyrolysis, the recycled carbon fibers from mechanical recycling have a lower quality. Therefore, despite the higher energy input, pyrolysis is a more promising approach to close the material cycle. Furthermore, recycled aggregate concrete can reduce emissions by a quarter compared to primary concrete. Finally, this work aimed to provide a basis for further life cycle optimization in the construction sector. In subsequent studies, the EoL must be combined with the production and use stages to depict the entire life cycle, identify possible trade-offs and compare the results with conventional construction methods or materials such as steel-reinforced concrete. Full article

Vaccine supply has a bottleneck in manufacturing capacity due to operation personnel and chemicals needed. Assessment of existing mRNA (messenger ribonucleic acid) vaccine processing show needs for continuous manufacturing processes. This is enabled by strict application of the regulatory demanded quality by design process based on digital twins, process analytical technology, and control automation strategies in order to improve process transfer for manufacturing capacity, reduction out-of-specification batch failures, qualified personnel training and number, optimal utilization of buffers and chemicals as well as speed-up of product release. In this work, process control concepts, which are necessary for achieving autonomous, continuous manufacturing, for mRNA manufacturing are explained and proven to be ready for industrialization. The application of the process control strategies developed in this work enable the previously pointed out benefits. By switching from batch-wise to continuous mRNA production as was shown in previous work, which was the base for this study, a potential cost reduction by a factor 5 (i.e., from EUR 0.380 per dose to EUR 0.085 per dose) is achievable. Mainly, based on reduction of personnel (factor 30) and consumable (factor 7.5) per campaign due to the significant share of raw materials in the manufacturing costs (74–97). Future research focus following this work may be on model-based predictive control to gain further optimization potential of potential batch failure and out of specification (OOS) number reduction. Full article

The production of food is highly complex due to the various chemo-physical and biological processes that must be controlled for transforming ingredients into final products. Further, production processes must be adapted to the variability of the ingredients, e.g., due to seasonal fluctuations of raw material quality. Digital twins are known from Industry 4.0 as a method to model, simulate, and optimize processes. In this vision paper, we describe the concept of a digital food twin. Due to the variability of the raw materials, such a digital twin has to take into account not only the processing steps but also the chemical, physical, or microbiological properties that change the food independently from the processing. We propose a hybrid modeling approach, which integrates the traditional approach of food process modeling and simulation of the bio-chemical and physical properties with a data-driven approach based on the application of machine learning. This work presents a conceptual framework for our digital twin concept based on explainable artificial intelligence and wearable technology. We discuss the potential in four case studies and derive open research challenges. Full article

Heavy metal pollution is a serious concern of the modern era due to its widespread negative effects on human health and to the environment. Conventional technologies applied for the uptake of this category of persistent pollutants are complex, often expensive, and inefficient at low metal concentrations. In the last few years, non-conventional alternatives have been studied in search of better solutions in terms of costs and sustainability. Microbial adsorbents are one of the biomass-based sorbents that have extensively demonstrated excellent heavy metals removal capacity even at low concentrations. However, most of the carried-out research regarding their application in wastewater treatment has been performed in discontinuous systems. The use of microorganisms for the uptake of metal ions in continuous systems could be an important step for the upscale of the remediation processes since it facilitates a faster remediation of higher quantities of wastewaters loaded with heavy metals, in comparison with batch systems removal. Thus, the current research aims to analyze the available studies focusing on the removal of metal ions from wastewaters using microorganisms, in continuous systems, with a focus on obtained performances, optimized experimental conditions, and the sustainability of the bioremoval process. The present work found that microbial-based remediation processes have demonstrated very good performances in continuous systems. Further sustainability analyses are required in order to apply the bioremediation technology in an optimized environmentally friendly way in large-scale facilities. Full article

Industry 4.0 has embraced process models in recent years, and the use of model-based digital twins has become even more critical in process systems engineering, monitoring, and control. However, the reliability of these models depends on the model parameters available. The accuracy of the estimated parameters is, in turn, determined by the amount and quality of the measurement data and the algorithm used for parameter identification. For the definition of the parameter identification problem, the ordinary least squares framework is still state-of-the-art in the literature, and better parameter estimates are only possible with additional data. In this work, we present an alternative strategy to identify model parameters by incorporating differential flatness for model inversion and neural ordinary differential equations for surrogate modeling. The novel concept results in an input-least-squares-based parameter identification problem with significant parameter sensitivity changes. To study these sensitivity effects, we use a classic one-dimensional diffusion-type problem, i.e., an omnipresent equation in process systems engineering and transport phenomena. As shown, the proposed concept ensures higher parameter sensitivities for two relevant scenarios. Based on the results derived, we also discuss general implications for data-driven engineering concepts used to identify process model parameters in the recent literature. Full article

The handling of bulk solids in the form of powders is a fundamental process in a wide range of manufacturing industries, such as the automotive, aerospace, food, and healthcare sectors. All these sectors employ additive manufacturing (AM), as it enables the production of complex parts in a short amount of time. Thus, it is considered an established method for developing an agile manufacturing environment that can drastically reduce the lead time from conception to the production stage. At the same time, powder is a unique material sensitive to environmental and machine conditions; hence, establishing an optimal configuration is not straight-forward. This work presents a discrete element method (DEM) simulation of an experimental dosing system used in AM. We introduce a robust workflow that correlates suitable experimental data with simulation results, establishing models of real powders with different flowability. The results showed an excellent agreement between the experimental data and the simulation results and provided a better understanding of the material behavior. Furthermore, we employed a coarse-grained approach to extract continuum fields from the discrete data. The results showed that the cohesion level in the system was enough to create agglomerates that hindered the transport of the material and produced nonuniform distribution. Full article

Avocados are one of the important fruits in our diet, showing many health benefits. However, a significant amount of avocados become defective as they are transported throughout the supply chain and are refused by consumers, ending up at animal or pet feed manufacturers. Indeed, some previous evidence suggests that rejected avocados still present high phenolic content that can be reused in the drug or pharmacological industry. Therefore, in the present work, we measured the phenolic content from rejected avocado pulp and evaluated the antioxidant potential, followed by characterization and quantification using LC-ESI-QTOF-MS/MS and HPLC-PDA. Reed avocado pulp was highest in TPC (0.21 mg GAE/g f.w.) and TFC (0.05 mg QE/g f.w.), whereas in TCT assay, low traces of tannins were exhibited in Wurtz and Reed avocado pulp. Hass avocado pulp had the highest antioxidant potential in DPPH (0.32 AAE/g f.w.), FRAP (0.13 AAE/g f.w.), ABTS (0.32 AAE/g f.w.), •OH-RSA (0.51 AAE/g f.w.) and FICA (0.47 mg EDTA/g) assays. Wurtz avocado pulp had higher antioxidant potential in RPA (0.07 mg AAE/g) and PMA (0.27 AAE/g f.w.). A total of 64 phenolic compounds were characterized in avocado pulp, including 10 in Hass avocado pulp, 31 in Wurtz avocado pulp and 45 in Reed avocado pulp. In HPLC-PDA quantification, chlorogenic acid (21.36 mg/g f.w.), epicatechin (14.24 mg/g f.w.) and quercetin (21.47 mg/g f.w.) were detected to be the highest in Hass, Wurtz and Reed avocado pulp, respectively. Our study showed the presence of phenolic compounds in rejected avocado pulp and hence can be utilized in food and pharmaceutical industries. Full article

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 particles the hindered settling velocity is proportional to the porosity of a suspension cloud on exponent 4.8, which was confirmed by our verification experiment, for the studied fiber particles it is proportional to the porosity on exponent 22.1. This great increase in the exponent is an effect of both the shape of the particles and, in particular, a mutual influence that arises from their interweaving and connection in the suspension. Full article