Editor’s Choice Articles

Freeze-drying is a common process to extend the shelf life of food and bioactive substances. Its main drawback is the long drying time and associated high production costs. Microwaves can be applied to significantly shorten the process. This study investigates the effects of modulating the electromagnetic field in microwave-assisted freeze-drying (MFD). Control concepts based on microwave frequency are evaluated using electromagnetic simulations. The concepts are then applied to the first part of primary drying in a laboratory-scale system with solid-state generators. Targeted frequency modulation in the electromagnetic simulations enabled an increase in energy efficiency or heating homogeneity throughout MFD while having negligible effects on the power dissipation ratio between frozen and dried product areas. The simulations predicted the qualitative effects observed in the experimental proof of concept regarding energy efficiency and drying homogeneity. Additionally, shortened drying times were observed in the experiments with a targeted application of energy-efficient frequencies. However, differences occurred in the quantitative validation of the electromagnetic models for energy efficiency in dependence on frequency. Nevertheless, the models can be used for a time-efficient investigation of the qualitative effects of the control concepts. In summary, frequency-based control of MFD represents a promising approach for process control and intensification. Full article

Full-scale wastewater treatment plants utilizing aerobic granular sludge technology are being built in many countries worldwide. As with all biological wastewater treatment plants, the produced waste biomass must be stabilized to protect the population, wildlife, and the environment. Digestion is usually used to break down the complex organics in the waste sludge; however, the digestibility of aerobic granular sludge still needs to be fully understood compared to the conventional activated sludge. This paper reviews the studies published on the digestibility of waste aerobic granular sludge to date. Studies comparing aerobic granular sludge and activated sludge in terms of composition, properties, and digestibility are highlighted. The impact of biological composition and physical properties on the digestibility of sludge is reviewed in terms of biomethane production and biodegradability. The effect of pre-treatment is also covered. Areas for future research are presented. Full article

When designing crash absorber particles for application as a filling material in the double-hull of ships, the main goal is to achieve an optimal mechanical performance, in combination with a low-density particle structure, while fulfilling several additional requirements regarding, for example, non-toxic and hydrophobic behavior. In this study, a fluidized bed was used to coat Poraver^® glass particles with Candelilla wax and silicone to attain these specifications. A uniform coating was achieved with wax, but the process turned out to be far more challenging when using silicone. To evaluate the suitability of coated particles as a granular filling material, and to compare their performances with that of untreated Poraver^® particles, several mechanical tests, as well as structural investigations, were conducted. While no notable improvement in mechanical behavior was observed on the single-particle level, bulk tests showed promising results regarding compressibility and abrasion resistance of coated particles compared to untreated ones. Full article

The demand for products based on natural ingredients is increasing among cosmetic and textile consumers. Cork extracts contain components of interest with special properties, including antioxidant, anti-inflammatory, and antibacterial activities, that might improve the effectiveness of cosmetic formulations currently on the market and may impart new characteristics to textiles. The main goal of this work was to investigate the effect of the incorporation of three cork extracts into two commercial cosmetic formulations (formulation A and B) and evaluate their role as textile dyeing agents. The extracts (E1, E2, and E3) were obtained from cork powder using natural deep eutectic solvents (NADES) (E1-NADES 1: lactic acid:glycerol, E2-NADES 2: lactic acid:glycine, and E3-NADES 3: lactic acid:sodium citrate) and applied in combination with the solvent. The impact of the extracts on the cosmetic formulations’ properties was evaluated in terms of pH, viscosity, antioxidant activity, transdermal permeation capacity, cytotoxicity, and organoleptic characteristics (odor, color, and appearance). The results demonstrated that the cork extracts improved the antioxidant performance of the formulations (90% reduction in DPPH (1,1-difenil-2-picril-hidrazil)). Moreover, low concentrations (5 mg/mL and 10 mg/mL) of extract did not present a cytotoxic effect on keratinocytes. Cotton fabrics were efficiently dyed with the NADES-based cork extracts which conferred to these substrates antioxidant (78% in DPPH reduction) and antibacterial abilities (inhibition halos: 12–15 mm). The application of cork extracts as ingredients in cosmetics or as dyeing/coloration agents for textile coloration is revealed to be a promising and green route to replace harmful ingredients normally used in industry. Full article

Manufacturing and energy sectors provide vast amounts of maintenance data and information which can be used proactively for performance monitoring and prognostic analysis which lead to improve maintenance planning and scheduling activities. This leads to reduced unplanned shutdowns, maintenance costs and any fatal events that could affect the operations of the overall system. Performance and condition monitoring are among the most used strategies for prognostic and health management (PHM), in which different methods and techniques can be implemented to analyse maintenance and online data. Offshore wind turbines (WTs) are complex systems increasingly needing maintenance. This study proposes a performance monitoring system to monitor the performance of the WT power generation process by exploiting artificial neural networks (ANN) composed of different network designs and training algorithms, using simulated supervisory control and data acquisition (SCADA) data. The performance monitoring is based on different operating modes of the same type of wind turbine. The degradation models were developed based on the generated active power resulting from different degradation levels of the gearbox, which is a critical component of the WTs. The deviations of the wind power curves for all operating modes over time are monitored in terms of the resulting power residuals and are modelled using ANN with a unique network architecture. The monitoring process uses the recursive form of the cumulative summation (CUSUM) change detection algorithm to detect the state change point in which the gearbox efficiency is degraded by evaluating the power residuals predicted by the ANN model. To increase the monitoring effectiveness, a second ANN model was developed to predict the gearbox efficiency to monitor any failure that could happen once the efficiency degrades below a threshold. The results show a high degree of accuracy in power and efficiency prediction in addition to monitoring the abnormal state or deviations of the power generation process resulting from the degraded gearbox efficiency and their corresponding time slots. The developed monitoring method can be a valuable tool to provide maintenance experts with alarms and insights into the general state of the power generation process, which can be used for further maintenance decision-making. Full article

The aldol condensation of furfural and acetone is considered a promising method for the production of liquid fuel intermediates. 4-(2-furyl)-3-buten-2-one (FAc) and 1,5-di-2-furanyl-1,4-pentadien-3-one (F2Ac) are the main products of the reaction, which can go through the hydrodeoxygenation process to convert to diesel and jet fuel range fuels. Considering the present situation at the fuel-market related to crude oil shortage, the above-mentioned process seems to be a convenient path to obtain fuels in the diesel and kerosene range. This research focuses on the effect of water on the furfural conversion and product distribution during the aldol condensation. The catalyst chosen for this research was MgAl mixed oxide in molar ratio 3:1. The reaction was performed at 40 °C and 1 MPa in a continuous-flow reactor with and without water in the feedstock. The physicochemical properties of the catalyst were evaluated using different techniques. The catalyst lifetime decreased and the catalyst deactivation started faster by the addition of 5 wt.% water to the feedstock with the furfural to acetone ratio (F:Ac) of 1:2.5. Selectivity to FAc increased by 10% in the presence of water. The catalyst lifetime enhanced by increasing the F:Ac ratio from 1:2.5 to 1:5, in the presence of 5 wt.% water. The furfural conversion was 100% after 28 h of reaction, and then decreased gradually to 40% after 94 h of reaction. At higher F:Ac ratio, the selectivity to FAc was 10% higher, while the F2Ac was about 8% lower. Full article

A standardized method to evaluate the material properties of surimi gels has to be updated because of the lack of accuracy and the repeatability of data obtained from conventional ways. To investigate the relationships between the different texture measurement methods used in surimi gels, 250 batches of different surimi gels were used. The textural properties of surimi gels made with or without whey protein concentrate (SG-WP), potato starch (SG-PS), or dried egg white (SG-EW) were measured under torsion, tensile, and penetration tests. The correlation between the textural properties related to the deformation and hardness of surimi gels without any added ingredients (SG) was linear (R² > 0.85). However, the R² values of the shear strain and tensile strain of SG-WP and SG-EW were significantly lower than that of SG. The strain distributions of surimi gels with and without added ingredients were estimated by digital image correlation (DIC) analysis. The results showed that the local strain concentration in SG-WP and SG-EW was significantly higher than that of SG in the failure ring tensile test and the torsion test (p < 0.05). DIC analysis was an effective tool for evaluating the strain distribution characteristics of surimi gels upon fracture from torsion, penetration, and tension. Full article

Several chemicals, such as pesticides and heavy metals, are frequently encountered together in environment matrices, becoming a priority concerning the prevention of their emissions, as well as their removal from the environment. In this sense, this work aimed to evaluate the effectiveness of a permeable biosorbent bio-barrier reactor (PBR) on the removal of atrazine and heavy metals (copper and zinc) from aqueous solutions. The permeable bio-barrier was built with a bacterial biofilm of R. viscosum supported on 13X zeolite. One of the aims of this work is the investigation of the toxic effects of atrazine, copper and zinc on the bacterial growth, as well as the assessment of their ability to adapt to repeated exposure to contaminants and to degrade atrazine. The growth of R. viscosum was not affected by concentrations of atrazine bellow 7 mg/L. However, copper and zinc in binary solutions were able to inhibit the growth of bacteria for all the concentrations tested (5 to 40 mg/L). The pre-acclimation of the bacteria to the contaminants allowed for an increase of 50% of the bacterial growth. Biodegradation tests showed that 35% of atrazine was removed/degraded, revealing that this herbicide is a recalcitrant compound that is hard to degrade by pure cultures. The development of a PBR with R. viscosum supported on zeolite was successfully performed and the removal rates were 85% for copper, 95% for zinc and 25% for atrazine, showing the potential of the sustainable and low-cost technology herein proposed. Full article

This study used computational fluid dynamics for low greenhouse effect refrigerant (R-513A) simulation analysis in the two-stage 150 USRT class oil-free centrifugal refrigerant compressor using integrated part load value (IPLV) and internal flow field. The compressor rotor speed and mass flow rate for the IPLV working conditions with various loads were planned using Stage 1 and Stage 2 simulations, respectively. The performance and flow field numerical simulation analyses for the two-stage centrifugal compressor is discussed. This study used Ansys-CFX software for numerical simulation analysis and the conservation form of a 3D steady-state Navier–Stokes equation set with the finite volume discretization method for computation. The computing mode produced better computing efficiency and flexible mesh setting using the k-omega (k-ω) model, which has better computational performance in the near wall boundary layer and low Reynolds number flow field (used as the turbulence model) for simulation. The R-513A refrigerant property setting was calculated using the Soave–Redlich–Kwong gas equation. This study discusses the shaft work, pressure ratio, and isentropic efficiency and also describes the main research findings with the meridional pressure, isentropic efficiency contour maps, and flow field velocity vector diagrams. According to the numerical simulation results, in Stage 1 and Stage 2 simulations, the isentropic efficiency produced the highest numerical results in the 75% load case, which are 88.19% and 89.06%, respectively. The isentropic efficiency decreased to 75.93% and 82.26%, respectively, in the 25% load case. The flow field velocity vector diagram shows that in the 25% load case, there was back-flow field distribution near the impeller shroud. The compressor performance was also analyzed. Full article

In water-in-oil-in-water (W₁/O/W₂) double emulsions several irreversible instability phenomena lead to changes. Besides diffusive processes, coalescence of droplets is the main cause of structural changes. In double emulsions, inner droplets can coalesce with each other (W₁–W₁ coalescence), inner droplets can be released via coalescence (W₁–W₂ coalescence) and oil droplets can coalesce with each other (O–O coalescence). Which of the coalescence pathways contributes most to the failure of the double emulsion structure cannot be determined by common measurement techniques. With monodisperse double emulsions produced with microfluidic techniques, each coalescence path can be observed and quantified simultaneously. By comparing the occurrence of all possible coalescence events, different hydrophilic surfactants in combination with PGPR are evaluated and discussed with regard to their applicability in double emulsion formulations. When variating the hydrophilic surfactant, the stability against all three coalescence mechanisms changes. This shows that measuring only one of the coalescence mechanisms is not sufficient to describe the stability of a double emulsion. While some surfactants are able to stabilize against all three possible coalescence mechanisms, some display mainly one of the coalescence mechanisms or in some cases all three mechanisms are observed simultaneously. Full article

Retrospective analysis of historic data for cell culture processes is a powerful tool to develop further process understanding. In particular, deploying retrospective analyses can identify important cell culture process parameters for controlling critical quality attributes, e.g., afucosylation, for the production of monoclonal antibodies (mAbs). However, a challenge of analyzing large cell culture data is the high correlation between regressors (particularly media composition), which makes traditional analyses, such as analysis of variance and multivariate linear regression, inappropriate. Instead, partial least-squares regression (PLSR) models, in combination with machine learning techniques such as variable importance metrics, are an orthogonal or alternative approach to identifying important regressors and overcoming the challenge of a highly covariant data structure. A specific workflow for the retrospective analysis of cell culture data is proposed that covers data curation, PLS regression, model analysis, and further steps. In this study, the proposed workflow was applied to data from four mAb products in an industrial cell culture process to identify significant process parameters that influence the afucosylation levels. The PLSR workflow successfully identified several significant parameters, such as temperature and media composition, to enhance process understanding of the relationship between cell culture processes and afucosylation levels. Full article

The paper analyzes the effect of severe plastic deformation by the high-pressure torsion (HPT) on phase transformations, in particular, on the formation of the ω-phase, and on mechanical properties, such as hardness and Young’s modulus, in Ti alloys with 1.5 and 15 wt.% Mo. Both alloys were pre-annealed at 1000 °C for 24 h and quenched. The microstructure of the initial Ti–1.5 wt.% Mo alloy consisted of the α-phase and α’-martensite, and the initial Ti–15 wt.% Mo alloy contained polycrystalline β solid solution. The hardness tests of the samples were carried out under the load of 10 and 200 mN. The annealed alloys were subjected to HPT, and the micro- and nanohardness of both deformed samples increased up to ~1 GPa compared to their initial state. It turned out that the values of hardness (H) and Young’s modulus (E) depend on the applied load on the indenter: the higher the applied load, the lower H and higher E. It was also found that the HPT leads to the 30% increase in E for an alloy with 1.5 wt.% Mo and to the 9% decrease in E for the alloy with 15 wt.% Mo. Such a difference in the behavior of the Young’s modulus is associated with phase transformations caused by the HPT. Full article

This study represents a first time that perstraction was assessed as a process to remove perfluorooctanoic acid (PFOA) from water. In the perstraction process, PFOA permeates through a membrane from water to a solvent. The membrane used in this study was polydimethylsiloxane (PDMS). The experimental approach included the following: (1) measurement of partition coefficients for PFOA between water and selected solvents; (2) determination of solubility and diffusivity of the solvents in PDMS; (3) determination of the uptake of PFOA in PDMS; (4) determination of the effects of selected particles imbedded in the PDMS on PFOA uptake and solvent absorption; and (5) demonstration of the perstraction process to remove PFOA from water. PFOA preferentially partitioned to alcohols over water. In addition, ZnO and CuO particles in PDMS significantly enhanced the rate at which PFOA was absorbed in PDMS from deionized water due to ionic interactions. The perstraction of PFOA from deionized water into hexanol was demonstrated. However, perstraction was not successful at removing PFOA from tap water. While the application of perstraction to removing PFOA from water is limited, the idea was demonstrated and information contained within this manuscript is new. Full article

Producing highly efficient electric motors remains a challenge nowadays. Given that the legislation in the field requires the transition to the production of engines with increased efficiency, for manufacturing companies, switching from one generation of engines to another can be a difficult task. This paper analyzes ways to adapt the assembly of engines of the IE4 generation starting from the assembly lines of the engines of the previous generation, IE3. The analysis of the assembly process covers both the operator training part and the actual assembly part. Ten possible variants for the assembly line and specific decisional variables have been defined. The decision to choose the optimal assembly configuration was made using as management tools the matrix of consequences and utilities. The validation of the theoretical model of the assembly line was carried out through a case study built for two classes of electric motors, namely G90 and G180. For a total production of IE4 electric motors of 20,000 parts/month, the analyzed variants, respectively, the two sizes (G90 and G100) represent 35% (7000 parts/month) of the G90 size and 22% (4400 parts/month) the G100 size. The aim is to provide a new modular assembly concept, which depending on the orders, can use, as given in the conclusion of this article. Full article

Flavoured oils arouse great interest among consumers in many countries due to their variety of flavours and versatility, especially in the culinary field. The aromatization of oils seeks to improve their sensory and nutritional properties, and extend their useful life due to the added substances can be beneficial as antioxidant and antimicrobial agent. In this research, olive oils of the ‘Madural’ variety from Trasos Montes region of Portugal have been obtained and flavoured with different aromatics herbs and condiments (flower of salt and bay leaf, garlic, rosemary and dehydrated lemon peel). The objective is to study the influence of the aromatic herbs and condiments on the physicochemical parameters of the oils: quality, purity, oxidative stability and microbiological analysis. It can be noted that the flavourings do not significantly alter the quality of the monovarietal oil, although, for some parameters, the excessive contact times can affect the category of the oil. On the other hand, the high content of antioxidants provided by flavouring agents can favour its stability and prolong its expiration. In this sense, the flavouring agent that contributes to stop the oxidation of the oil over time is salt + bay leaves, as higher oxidative stability values were detected than those obtained in monovarietal oil. However, oils flavoured with rosemary or lemon show a decrease over time for this parameter, which could indicate that this flavouring accelerates oxidation. In the case of oxidative stability referred to those flavoured with garlic, they present similar values to the monovarietal. The effect exerted by flavourings on the different parameters of the oils is complex, since it is influenced by the method followed and the operating variables established for flavouring. Full article

ABTS (2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic) acid) is a widely used compound for determining the total antioxidant capacity (TAC) of plant extracts, food, clinical fluids, etc. This photometric assay is based on the reduction by the presence of antioxidant compounds of a well-known metastable radical ($ABT{S}^{•+}$) which can be formed via several different approaches and be used in many different determination methodologies such as automated photometric measures in microplates, clinical robots, valuable titrations, and previous liquid chromatographic separation. Another interesting aspect is that, in some cases, the ABTS/TAC method permits sequential hydrophilic and lipophilic antioxidant activity determinations, obtaining total antioxidant activity values through the summatory data of both types of antioxidants. In this work, we present a review of several aspects of the ABTS/TAC, highlighting the major achievements that have made this method so widely used, e.g., ABTS radical formation in hydrophilic or lipophilic reaction media, measurement strategies, automatization, and adaptation to high-throughput systems, as well as the pros and cons. Moreover, some recent examples of ABTS/TAC method applications in plant, human, and animal samples are discussed. Full article

This article describes the performance of hemp shives, a co-product of the hemp industry, when used as an adsorbent to recover copper present in aqueous solutions by a batch method. Two materials provided by an industrial partner, namely water-washed hemp shives (SHI-W) and Na₂CO₃-activated shives (SHI-C), were studied. Two important variables in the water treatment industry, i.e., pH and ionic strength of the solution, were studied to evaluate their impact on the purification performance of the materials. The results obtained clearly indicated that the performance in terms of Cu removal obtained from the SHI-C material was significantly higher than that obtained with SHI-W, mainly due to the structural and chemical modifications after carbonate treatment. For each dose of this adsorbent, a percentage of recovery between 90 and 100% was achieved, independently of the pH value in the range 3–5. In the case of SHI-W, the highest values were between 60 and 75% and were both dependent on the pH and the dose used. SHI-C was also able to selectively remove 70% of copper in the presence of NaCl 1 M. The analysis of the isotherms indicated the presence of a complex adsorption mechanism that cannot be described by only one isotherm model. Full article

In this study, an aerosol fluidized bed is used to coat particles. A new aerosol generator is used to obtain coating solution droplets with a diameter of around 1 $\mathsf{\mu }$m or smaller. Glass particles, which have a mean diameter of 653 $\mathsf{\mu }$m, were the non-porous core material and the coating solution was sodium benzoate. Scanning electron microscope pictures were analyzed by MATLAB image processing for evaluating the coverage with the curvature effect. Monte Carlo simulation was used to describe the coating of fluidized particles by aerosol droplets. The purpose of this work was the determination of possible island growth on particles, and investigation of the reasons of it by comparing the experimental and simulation results. The preferential deposition of droplets on already occupied positions is seen as the main possible reason for island growth. Full article

The heat and mass transfer to solid particles in one-dimensional oscillating flows are investigated in this work. A meta-correlation for the calculation of the Nusselt number (Sherwood number) is derived by comparing 33 correlations and data point sets from experiments and simulations. These models are all unified by their dependencies on the amplitude parameter ${10}^{-3}\le ϵ\le {10}^3$ and the Reynolds number ${10}^{-1}\le Re\le {10}^6$, while the $ϵ$-$Re$ plane is applied as a framework in order to graphically display the various models. This is the first study to consider this problem in the entire $ϵ$-$Re$ plane quantitatively while taking preexisting asymptotic models for various areas of the $ϵ$-$Re$ plane into account. Full article

Demand trends towards mass customization drive the need for increasingly productive and flexible assembly operations. Walking-worker assembly lines can present advantages over fixed-worker systems. This article presents a multiproduct parallel walking-worker assembly line with shared automated stations, and evaluates its operational performance compared to semiautomated and manual fixed-worker lines. Simulation models were used to set up increasingly challenging scenarios based on an industrial case study. The results revealed that semiautomated parallel walking-worker lines could achieve greater productivity (+30%) than fixed-worker lines under high-mix low-volume demand conditions. Full article

CO₂ biomethanisation is a rapidly emerging technology which can contribute to reducing greenhouse gas emissions through the more sustainable use of organic feedstocks. The major technical limitation for in situ systems is that the reaction causes CO₂ depletion which drives up pH, potentially leading to instability and even digestion failure. The study aimed to test fundamentally derived predictive equations as tools to manage H₂ addition to anaerobic digesters. The methodology used data from the literature and from experimental digesters operated with excess H₂ to a point of failure and subsequent recovery. Two equations were tested: the first relating pH to CO₂ partial pressure (pCO₂), and the second extending this to include the influence of volatile fatty acids and ammonia. The first equation gave good agreement for data from studies covering a wide range of operating conditions and digester types. Where agreement was not good, this could usually be explained, and in some cases improved, using the second equation, which also showed excellent predictive performance in the experimental study. The results validated the derived equations and identified typical coefficient values for some organic feedstocks. Both equations could provide a basis for process control of CO₂ biomethanisation using routine monitoring of pH or pCO₂ with additional analysis for volatile fatty acids and total ammonia nitrogen when required. Full article

Carbon nitride (C₂N), a two-dimensional material, is rapidly gaining popularity in the photovoltaic (PV) research community owing to its excellent properties, such as high thermal and chemical stability, non-toxic composition, and low fabrication cost over other thin-film solar cells. This study uses a detailed numerical investigation to explore the influence of C₂N-based solar cells with zinc magnesium oxide (Zn_1−xMg_xO) as a buffer layer. The SCAPS-1D simulator is utilized to examine the performance of four Mg-doped buffer layers (x = 0.0625, 0.125, 0.1875, and 0.25) coupled with the C₂N-based absorber layer. The influence of the absorber and buffer layers’ band alignment, quantum efficiency, thickness, doping density, defect density, and operating temperature are analyzed to improve the cell performance. Based on the simulations, increasing the buffer layer Mg concentration above x = 0.1875 reduces the device performance. Furthermore, it is found that increasing the absorber layer thickness is desirable for good device efficiency, whereas a doping density above 10¹⁵ cm⁻³ can degrade the cell performance. After optimization of the buffer layer thickness and doping density at 40 nm and 10¹⁸ cm⁻³, the cell displayed its maximum performance. Among the four structures, C₂N/Zn_0.8125Mg_0.1875O demonstrated the highest PCE of 19.01% with a significant improvement in open circuit voltage (V_oc), short circuit density (J_sc), and fill factor (FF). The recorded results are in good agreement with the standard theoretical studies. Full article

The ambitious targets set by the International Maritime Organization for reducing greenhouse gas emissions from shipping require radical actions by all relevant stakeholders. In this context, the interest in high efficiency and low emissions (even zero in the case of hydrogen) fuel cell technology for maritime applications has been rising during the last decade, pushing the research developed by academia and industries. This paper aims to present a comparative review of the fuel cell systems suitable for the maritime field, focusing on PEMFC and SOFC technologies. This choice is due to the spread of these fuel cell types concerning the other ones in the maritime field. The following issues are analyzed in detail: (i) the main characteristics of fuel cell systems; (ii) the available technology suppliers; (iii) international policies for fuel cells onboard ships; (iv) past and ongoing projects at the international level that aim to assess fuel cell applications in the maritime industry; (v) the possibility to apply fuel cell systems on different ship types. This review aims to be a reference and a guide to state both the limitations and the developing potential of fuel cell systems for different maritime applications. Full article

From the textile manufacturers’ point of view, coarse and medullated fibers are undesirable in the production of fine woolen materials, but highly desirable in the production of textiles and yarns with special effects, especially in carpet production. For sustainability, the entire sheep fleece should be used, including the coarse and medullated fibers. The raw wool must be scoured to obtain clean wool fibers without damage or excessive fiber entanglement, with a certain moisture content, low dirt content and residual grease for further processing, and proper color. In order to remove the impurities in raw wool with maximum efficiency, save energy and minimize the environmental impact, this study investigated the changes in some fiber properties during the scouring process due to the effect of the enzyme complex on coarse wool fibers. The effects were studied through the amount of clean wool fibers and impurities within the fleece, the fiber diameter and color. Conventional and enzyme scoured coarse wool were bleached with an unconventional bleaching agent, percarbonate, and compared to bleaching with hydrogen peroxide to achieve higher whiteness and brilliant color with minimal fiber property changes. The changes after the bleaching process were determined based on the sorption of moisture and dyes and the color parameters. The bio-innovative pretreatment with enzyme complex scouring and percarbonate bleaching resulted in excellent fiber properties even for coarse wool. SEM analysis was performed to confirm these results. Taking into account the sustainability of the process and environmental protection, enzyme complex scouring and percarbonate bleaching are recommended as pretreatment processes for raw coarse wool. Full article

This study investigated the feasibility of applying an anaerobic step-feeding strategy to enhance the performance of granular sequencing batch reactors (GSBRs) in terms of operational stability of the cultivated mature granules and nutrient removal efficiencies. Two identical 5 L reactors were operated with a total cycle time of 8 h. GSBRs were operated with high-strength synthetic wastewater (COD = 1250 ± 43, ammonium (NH₄-N) = 115.2 ± 4.6, and orthophosphate (PO₄-P) = 17.02 ± 0.9 mg/L) for 360 days through three stages: (1) Cultivation, 125 days (>2.1 mm); (2) Maturation, 175 days (>3 mm); (3) alternate feed loading strategy for R2 only for 60 days (anaerobic step-feeding). The granulation process, the physical properties of the granules, the nutrients, and the substrate removal performance were recorded during the entire operational period. For the cultivation and maturation stages, both reactors followed the fast single feeding mode followed by anaerobic mixing, and the results indicated a strong correlation between R1 and R2 due to the same working conditions. During the cultivation stage, adopting high organic loading rate (OLR) at the reactor start-up did not accelerate the formation of granules. Removal efficiency of PO₄-P was less than 76% during the maturation period, while it exceeded 90% for COD, and was higher than 80% for NH₄-N without effect of nitrite or nitrate accumulations due to simultaneous nitrification–denitrification. After changing filling mode for R2 only, there was unexpected deterioration in the performance and a rapid disintegration of the matured granules (poor settleability) accompanied by poor effluent quality due to high content of suspended solids because of applying selection pressure of short settling time. Consequently, GSBRs operation under the effect of fast single feeding mode followed by anaerobic mixing favors stable long-term granule stability. Full article

With the spread of the Industry 4.0 concept, implementing Artificial Intelligence approaches on the shop floor that allow companies to increase their competitiveness in the market is starting to be prioritized. Due to the complexity of the processes used in the industry, the inclusion of a real-time Quality Prediction methodology avoids a considerable number of costs to companies. This paper exposes the whole process of introducing Artificial Intelligence in plastic injection molding processes in a company in Portugal. All the implementations and methodologies used are presented, from data collection to real-time classification, such as Data Augmentation and Human-in-the-Loop labeling, among others. This approach also allows predicting and alerting with regard to process quality loss. This leads to a reduction in the production of non-compliant parts, which increases productivity and reduces costs and environmental footprint. In order to understand the applicability of this system, it was tested in different injection molding processes (traditional and stretch and blow) and with different materials and products. The results of this document show that, with the approach developed and presented, it was possible to achieve an increase in Overall Equipment Effectiveness (OEE) of up to 12%, a reduction in the process downtime of up to 9% and a significant reduction in the number of non-conforming parts produced. This improvement in key performance indicators proves the potential of this solution. Full article

Phthalates are ubiquitous pollutants that are currently classified as endocrine disruptor chemicals causing serious health problems. As contaminants of food and beverages, they come into contact with the epithelium of the intestinal tract. In this work, a SPE-HPLC-PDA method for the determination of phthalates in water from plastic bottles was developed and validated according to the food and drug administration (FDA) guidelines. A chromatographic separation was achieved using a mobile phase consisting of ammonium acetate buffer 10 mM pH 5 (line A) and a mixture of methanol and iso-propanol (50:50 v/v, line B) using gradient elution. Several SPE cartridges and different pH values were investigated for this study, evaluating their performance as a function of recovery. Among these parameters, pH 5 combined with the SPE sep pack C₁₈ cartridge showed the best performance. Finally, the proposed method was applied to the analysis of real samples, which confirmed the presence of phthalates. A colonic epithelial cell model was used to evaluate the effects of these phthalates at the concentrations found in water from plastic bottles. In cells exposed to phthalates, the increased expression of factors, which control the signaling pathways necessary for intestinal epithelium homeostasis, inflammatory response, and stress was detected. The proposed method falls fully within the limits imposed by the guidelines with precision (RSD%) below 7.1% and accuracy (BIAS%) within −4.2 and +6.1. Full article

The performances of four different designs for a pilot-scale spray dryer have been evaluated and compared based on experimentally measured particle residence time distributions (RTD), recovery rates and physical properties of spray-dried fresh skim milk. The RTDs have been measured using a dye pulse injection method, and the measurements have been fitted to models using continuous stirred-tank reactors in series (CSTR-TIS) for quantitative performance evaluation and comparison. Conical drying chambers and a box connection design have been used in the latest dryer design to reduce the amount of wall deposition and provide a smoother gas flow pattern. The particle-to-gas mean residence time ratio for the latest design is significantly closer to unity (1.6 s/s to 1.0 s/s) compared with earlier designs (2.6 s/s to 1.5 s/s). The latest design has a wider spread of RTD (n = 5–8) compared with earlier designs (n = 13–18), which may be linked to the recirculation zone in the box connection. Although the latest design has a wider spread of RTD, the conical design has shown promising results compared with a cylindrical drying chamber in terms of overall wall deposition behaviours. Full article

The use of photogrammetry provides an inexpensive, alternative method that can simplify the processes traditionally carried out in the orthotics workshop. The objectives of this study are to develop a method based on photogrammetry to obtain 3D-printed positive foot casts for fabricating thermoconformed orthoses from a negative cast in phenolic foam. Using a basic Smartphone, a photo capture protocol for feet, free software and a 3D printer, we tested the suitability of the positive cast obtained to fabricate custom foot orthoses using thermoconformed 3 mm polypropylene in the orthotics laboratory. The results show that digitally fabricated casts provide a very close replicate of the positive casts obtained traditionally through plaster casting (maximum dimension discrepancy between casts of 2 mm in length and 0.4 mm in forefoot, midfoot and rearfoot measurements). They are also suitable for the process of fabricating 2- and 3-mm polypropylene thermoconformed plantar orthoses. Photogrammetry can be used as a new method to obtain a positive 3D foot cast suitable for fabricating custom orthoses, in a valid, safe, cleaner and more lasting procedure that removes the process of plaster casting. Full article

Providing a cost-efficient feeding strategy for cell expansion processes remains a challenging task due to, among other factors, donor variability. The current method to use a fixed medium replacement strategy for all cell batches results often in either over- or underfeeding these cells. In order to take into account the individual needs of the cells, a model predictive controller was developed in this work. Reference experiments were performed by expanding human periosteum derived progenitor cells (hPDCs) in tissue flasks to acquire reference data. With these data, a time-variant prediction model was identified to describe the relation between the accumulated medium replaced as the control input and the accumulated lactate produced as the process output. Several forecast methods to predict the cell growth process were designed using multiple collected datasets by applying transfer function models or machine learning. The first controller experiment was performed using the accumulated lactate values from the reference experiment as a static target function over time, resulting in over- or underfeeding the cells. The second controller experiment used a time-adaptive target function by combining reference data as well as current measured real-time data, without over- or underfeeding the cells. Full article

The present review provides a catalogue of relevant renewable energy (RE) technologies currently available (regarding the 2030 scope) and to be available in the transition towards 2050 for the decarbonisation of Energy Intensive Industries (EIIs). RE solutions have been classified into technologies based on the use of renewable electricity and those used to produce heat for multiple industrial processes. Electrification will be key thanks to the gradual decrease in renewable power prices and the conversion of natural-gas-dependent processes. Industrial processes that are not eligible for electrification will still need a form of renewable heat. Among them, the following have been identified: concentrating solar power, heat pumps, and geothermal energy. These can supply a broad range of needed temperatures. Biomass will be a key element not only in the decarbonisation of conventional combustion systems but also as a biofuel feedstock. Biomethane and green hydrogen are considered essential. Biomethane can allow a straightforward transition from fossil-based natural gas to renewable gas. Green hydrogen production technologies will be required to increase their maturity and availability in Europe (EU). EIIs’ decarbonisation will occur through the progressive use of an energy mix that allows EU industrial sectors to remain competitive on a global scale. Each industrial sector will require specific renewable energy solutions, especially the top greenhouse gas-emitting industries. This analysis has also been conceived as a starting point for discussions with potential decision makers to facilitate a more rapid transition of EIIs to full decarbonisation. Full article

Demand for lithium-ion battery cells (LIB) for electromobility has risen sharply in recent years. In order to continue to serve this growing market, large-scale production capacities require further expansion and the overall effectiveness of processes must be increased. Effectiveness can be significantly optimized through innovative manufacturing technology and by identifying scrap early in the production chain. To enable these two approaches, it is imperative to quantify safety- and function-critical product features in critical manufacturing steps through appropriate measurement techniques. The overview in this paper on quality control in LIB production illustrates the necessity for improved inspection techniques with X-rays to realize a fast, online measurement of inner features in large-scale cell assembly with short cycle times and to visualize inner product-process interactions for the optimization in electrolyte filling. Therefore, two new inspection techniques are presented that contribute to overcoming the aforementioned challenges through the targeted use of X-rays. First, based on the results of previous experiments in which the X-ray beam directions were deliberately varied, a online coordinate measurement of anode-cathode (AC) overhang was developed using a line detector. Second, a new concept and the results of a continuous 2D visualization of the electrolyte filling process are presented, which can be used in the future to optimize this time-critical process step. By using a X-ray-permeable and portable vacuum chamber it is possible to quantify the influence of process parameters on the distribution of the electrolyte in the LIB. Full article

LNG technologies have long been used but only recently found widespread employment on medium and small scales compared to the traditional cycle of liquefaction, transport by ship, regasification and injection into the gas network. This has increased the direct use of LNG with the problem of limiting greenhouse gas emissions, linked to gas released principally in the event of prolonged absence of fuel drawing from the cryogenic tank. This study analyzes the energetic exploitation of BOG in small internal combustion engines. The effect on CO₂ equivalent emissions was evaluated, making a comparison with the BOG emission into the atmosphere directly or after burning. A 1 kW gasoline engine was selected for a 500-litre LNG tank and converted to gas fueling. The measured consumption and emissions resulted in compliance with a lower environmental impact compared to direct BOG release into the atmosphere despite simplified technical solutions, such a cheap and light 2-stroke engine. In contrast, only a 4-stroke engine has performance such as achieving a reduction in GHG emissions, up to zero, even compared to the case of BOG combustion before releasing it into the atmosphere. Full article

This study investigates the physical parameters that affect the flow patterns of soybeans with various moisture content (12% to 60%) at varying orifice sizes (20, 40, and 60 mm) in a cylindrical silo. The flow conditions required to obtain a steady mass flow during discharge were evaluated via experiments and three-dimensional discrete element method (DEM) simulation. The discharged mass flow rates at different flow conditions provided the critical size of the orifice. If the reduced diameter (D_red) of an orifice is >5.59, the flow showed a steady state. Based on the mass flow index (MFI), the flow patterns at 40% and 60% moisture content at 40 and 60 mm orifice sizes, respectively, showed funnel flows. although these flow conditions were satisfied to maintain a steady flow. The maximum wall pressure for the funnel flow showed the location of the interlocking phenomenon where the stagnant zone began during discharging. DEM simulation was validated through the mass profiles using the parameters obtained by the experiments. This study demonstrates that the experimental and analytical results with DEM simulation predict the flow behaviors of soybeans well at various moisture contents. These results are useful for designing silos for continuous food processing. Full article

Hypericum perforatum L. (St. John’s wort) is one of the most popular medicinal plants in the world. Due to its documented antimicrobial and antioxidant properties, it is used in the treatment of bacterial and viral infections as well as inflammations. It is also used to treat gastrointestinal diseases and mild to moderate depression. In recent years, there has been an increase in the popularity of herbal medicine. Many people collect their own herbs and dry them at home. A common choice for quick drying of fruits, vegetables and herbs at home are food dehydrator machines. There are not many publications in the scientific literature examining the quality of dried herbal material obtained in such dryers. We characterized St. John’s wort harvested in southern Poland and investigated the effect of specific drying methods on the volatile component profile. The herbal raw material was dried using three methods: indoors at room temperature, in an incubator at 37 °C and in a food dehydrator machine. Volatile components were analysed by HS-SPME GC/MS. The herb dried in a food dehydrator, compared to other drying methods, retained similar or slightly smaller amounts of the compounds from the mono- and sesquiterpenes group, aromatic monoterpenes, aromatic monoterpenoids, sesquiterpenoids, aromatic sesquiterpenes and alkanes. However, monoterpenoids and compounds coming from decomposition reactions, such as alcohols, short-chain fatty acids and esters, were noticed in larger quantities. Usage of a food dehydrator at home can be a convenient alternative to drying herbs. However, due to a different profile of volatile components depending on the drying method, the amount of biologically active substances needs to be considered. By using various methods of drying, the medical effects of herbs can be enhanced or weakened; therefore, further research in this direction should be continued. Full article

Thermal processing of white radish using retort sterilization at different temperatures was investigated according to the dimension of the package. Four different samples with the same weight and volume were placed in packages with different dimensions. The degree of sterilization (i.e., F₀-value) at the cold point targeted at 6 min was determined based on experimental data and heat transfer simulation. The sterilization time was considerably increased with a decrease in surface area to unit volume ratio (φ) at each temperature. The sterilization time for the sample with the highest φ (155.56) was approximately five times faster than the sample with the lowest φ (72.22) at all heating temperatures. Numerical simulation conducted with a proper heat transfer coefficient (h) showed mostly good agreement with the experimental data (RMSE < 2 °C). Changes in color and total phenolic content were higher for samples heated at higher temperatures. Hardness values of white radish samples measured for center and edge parts separately were more uniform for samples with a high φ. Results in this study suggest that optimizing heating conditions of root vegetables must consider their package dimensions to satisfy quality attributes after sterilization. Numerical simulation can be utilized as a useful tool to design the sterilization process. Full article

Hydrocracking is an energy-intensive process, and its control system aims at stable product specifications. When the main product is diesel, the quality measure is usually 95% of the true boiling point. Constant diesel quality is hard to achieve when the feed characteristics vary and feedback control has a long response time. This work suggests a feedforward model predictive control structure for an industrial hydrocracker. A state-space model, an autoregressive exogenous model, a support vector machine regression model, and a deep neural network model are tested in this structure. The resulting reactor temperature decisions and final diesel product quality values are compared against each other and against the actual measurements. The results show the importance of the feed character measurements. Significant improvements are shown in terms of product quality as well as energy savings through decreasing the heat duty of the preheating furnace. Full article

This article addresses the decentralized multi-performance (MP) fuzzy control problem of nonlinear large-scale descriptor (LSD) systems. The considered LSD system contains several subsystems with nonlinear interconnection and external disturbances, and the Takagi–Sugeno fuzzy model (TSFM) is adopted to represent each nonlinear subsystem. Based on the proportional-plus-derivative state feedback (PDSF) scheme, we aim to design a decentralized MP fuzzy controller that guarantees the stabilization, mixed H_∞, and passivity performance control (MHPPC), and the guaranteed cost control (GCC) performance of the closed-loop Takagi–Sugeno LSD (TSLSD) systems. Furthermore, we introduce the Lyapunov stability theory and the free-weighting matrix scheme to analyze the stability of the TSLSD system. The proposed sufficient conditions can be transformed as linear matrix inequality (LMI) forms through Schur’s complement, which can be easily solved with the LMI Toolbox. Finally, to illustrate the proposed approach, two examples and simulation results are presented. Full article

Understanding chemical processes at the single-molecule scale represents the ultimate limit of analytical chemistry. Single-molecule detection techniques allow one to reveal the detailed dynamics and kinetics of a chemical reaction with unprecedented accuracy. It has also enabled the discoveries of new reaction pathways or intermediates/transition states that are inaccessible in conventional ensemble experiments, which is critical to elucidating their intrinsic mechanisms. Thanks to the rapid development of single-molecule junction (SMJ) techniques, detecting chemical reactions via monitoring the electrical current through single molecules has received an increasing amount of attention and has witnessed tremendous advances in recent years. Research efforts in this direction have opened a new route for probing chemical and physical processes with single-molecule precision. This review presents detailed advancements in probing single-molecule chemical reactions using SMJ techniques. We specifically highlight recent progress in investigating electric-field-driven reactions, reaction dynamics and kinetics, host–guest interactions, and redox reactions of different molecular systems. Finally, we discuss the potential of single-molecule detection using SMJs across various future applications. Full article

A series of studies were conducted to demonstrate the feasibility of low-temperature bonding by the forming and heating an Al-8wt%Si alloy thick film on a B₄C surface by cold spraying. The results show that: (1) The cracks near the joining interface are closed by the Al alloy by the process studied in this study, and a joining strength of about 220 and 240 MPa is achieved by low temperature joining of 580 °C and 600 °C, respectively.; (2) The amount of weak intermetallic compounds at the joining interface is reduced; (3) It is assumed that the reduction in the amount of Al-B-C compounds is due to the formation of the β phase during the solidification process of the Al-Si alloy, which hinders the growth of the compounds.; (4) On the primary joint surface, a continuous void group is formed in the vicinity of the β phase that surrounds the α phase, causing a decrease in the joining strength. Full article

The antibiotic azithromycin (AZM) is one of the most persistent in the environment, with potential to cause serious health and environmental problems. As some polluting discharges containing this antibiotic can reach the soil, it is clearly relevant determining the ability of soils with different characteristics to retain it. In this research, AZM adsorption and desorption were studied for a variety of soils, using batch-type experiments. The results show that, at low doses of antibiotic added (less than or equal to 50 µmol L⁻¹), the adsorption always reached 100%, while when higher concentrations were added (between 200 and 600 µmol L⁻¹) the highest adsorption corresponded to soils with higher pH values. Adsorption data were fitted to the Linear, Langmuir and Freundlich models, with the latter showing the best fit, in view of the determination coefficient. No desorption was detected, indicating that AZM is strongly adsorbed to the soils evaluated, suggesting that the risks of environmental problems due to this contaminant are minimized for these edaphic media. These results can be considered relevant with respect to risk assessment and possible programming of measures aimed at controlling environmental contamination by emerging contaminants, especially from the group of antibiotics, and in particular from AZM. Full article

Low speed, low capacity, and poor scalability make size-exclusion chromatography (SEC) unattractive for use in the preparative separation of proteins. We discuss a novel z² cuboid SEC device that addresses these challenges. A z² cuboid SEC device (~24 mL volume) was systematically compared with a conventional SEC column having the same volume and packed with the same resin. The primary objective of this study was to use the same volume of SEC medium in a much more efficient way by using the novel device. At any given flow rate, the pressure drop across the z² cuboid SEC device was lower by a factor of 6 to 8 due to its shorter bed height and greater cross-sectional area. Under overloaded conditions, the peaks obtained during protein separation with the conventional column were poorly resolved and showed significant fronting, while those obtained with the z² cuboid SEC device were much better resolved and showed no fronting. At any given flow rate, better resolution was obtained with the z² cuboid SEC device, while for obtaining a comparable resolution, the flow rate that could be used with the z² cuboid SEC device was higher by a factor of 2 to 3. Hence, productivity in SEC could easily be increased by 200 to 300% using the z² cuboid SEC device. The scalability of the z² cuboid SEC device was also demonstrated based on a device with a 200 mL bed volume. Full article

A hierarchical structure based on a Deep LSTM Supervised Autoencoder Neural Network (Deep LSTM-SAE NN) is presented for the detection and classification of faults in industrial plants. The proposed methodology has the ability to classify incipient faults that are difficult to detect and diagnose with traditional and many recent methods. Faults are grouped into different subsets according to the degree of difficulty to classify them accurately in the proposed hierarchical structure. External pseudo-random binary signals (PRBS) are injected in the system to enhance the identification of incipient faults. The approach is illustrated on the benchmark process (Tennessee Eastman Process) in order to compare across different methodologies. The efficacy of the proposed method is shown by a comprehensive comparison between many recent and traditional fault detection and diagnosis methods in the literature for Tennessee Eastman Process. The proposed work results in significant improvements in the classification of faults over both multivariate linear model-based strategies and non-hierarchical nonlinear model-based strategies. Full article

The search for novel highly effective materials with target properties for different electrochemical purposes is active for now. Ceramic materials with high levels of ionic conductivity can be applied as electrolytic materials in solid oxide fuel cells and in electrolyzers. Layered perovskites are a novel class of ionic conductors demonstrating almost-pure proton transportation at mid-temperatures. Gadolinium-doped ceramic materials based on layered perovskite BaLa₂In₂O₇ were obtained and investigated for the first time in this study. The effect of the dopant concentrations on the hydration processes and on ionic conductivity was revealed. It was shown that compositions 0 ≤ x ≤ 0.15 of BaLa_2–xGd_xIn₂O₇ exhibited proton conductivity when under wet air and at mid-temperatures (lower than ~450 °C). Gadolinium doping led to an increase in the conductivity values up to an order of magnitude of ~0.5. The protonic conductivity of the most conductive composition BaLa_1.85Gd_0.15In₂O₇ was 2.7∙10⁻⁶ S/cm at 400 °C under wet air. The rare earth doping of layered perovskites is a prospective approach for the design of ceramics for electrochemical devices for energy applications. Full article

Essential oils (EOs) from Abies sachalinensis (Sakhalin fir), a conifer species found in Sakhalin Island and Hokkaido in Japan, effectively remove nitrogen dioxide and possess antifungal activity. EOs also exert a relaxing effect and enhance air quality. Underwater shock waves generate instantaneous high pressure that ruptures cell walls, enhancing the performance of steam distillation and oil extraction. In this study, we aimed to increase the yield and quality of A. sachalinensis extracts using shockwaves. Leaves and branches were subjected to shockwave pretreatment or left untreated before EO extraction by steam distillation. EO yield of untreated dried leaves was 2.4 g/kg of dry leaf weight (DW). Upon application of a 3.0 kV, 3.6 kJ shockwave, the yield increased with the number of shockwave cycles. After ten cycles, yield increased 13.6-fold. Pretreatment with shockwaves for 10 cycles resulted in approximately 6- and 13-fold reductions in total energy consumption relative to fresh and dried leaves, respectively. Antioxidant activity increased more than 30-fold in shockwave-pretreated leaves than in untreated dried leaves after 10 cycles. This novel process can significantly reduce the energy used for EO extraction in steam distillation, thereby contributing to the development of a sustainable, low-energy EO production system. Full article

In order to utilize the benefits of blackthorn flower polyphenols and provide their stabilization during processing and storage, and to facilitate their application in functional food products, this study aimed to evaluate the encapsulation parameters during the spray-drying process of blackthorn flower extract. The effect of the type of wall material (maltodextrin (MD) and its mixtures with gum arabic (GA) and inulin (IN)), its ratio to extract dry matter (0.5, 1, and 2) and drying temperature (120, 150, and 180 °C) on the concentration of different polyphenolic groups was studied. While the lowest applied amount of wall material at the lowest drying temperature enabled efficient encapsulation of all polyphenolic groups, the type of wall material applied caused significant differences in retention. The highest concentrations of both phenolic acids and flavonoids were achieved with the addition of 25% of GA in MD. Unlike the addition of GA, mixtures of MD with IN did not show a positive effect on the retention of polyphenols. Selected encapsulation parameters ensured the high retention of total phenolics, namely 87.87% of the content determined in the liquid extract prior to spray drying, thereby providing a polyphenol-rich product with great potential for application in functional food and the nutraceutical industry. Full article

Municipal solid waste treatment and disposal have become one of the major concerns in waste management due to the excessive production of waste and higher levels of pollution. To address these challenges and protect the environment in sustainable ways, the hydrothermal pretreatment (HTP) technique coupled with anaerobic digestion (AD) becomes a preferred alternative technology that can be used for municipal solid waste stabilization and the production of renewable energy. However, the impact of HTP parameters such as temperature, retention time, pH, and solid content on the fermentation of TWAS is yet to be well studied and analyzed. Hence this study was conducted to review the effect of hydrothermal pretreatment of thickened waste-activated sludge (TWAS) on fermentation and anaerobic digestion processes. Many studies reported that fermentation of TWAS at pretreatment temperature ranges from 160 °C to 180 °C resulted in a 50% increase in volatile fatty acid (VFA) yields compared to no pretreatment. However, for the AD process, HTP in the range of 175 °C to 200 °C with a 30–60 min retention time was considered the optimal condition for higher biogas production, with 30% increase in biodegradability and greater than 55% increase in biogas production. Even though there is a direct relationship between increased HTP temperature and the hydrolysis of TWAS, a pretreatment temperature range beyond 200 °C alters the biogas production. The solid content (SC) of sludge plays a crucial role in HTP, where in practice up to 16% SC has been utilized for HTP. Further, a combined alkaline-HTP enhances the process performance. Full article

The last-mile logistics is regarded as one of the least efficient, most expensive, and polluting part of the entire supply chain and has a significant impact and consequences on sustainable delivery operations. The leading business model in e-commerce called Attended Home Delivery is the most expensive and demanding when a short delivery window is mutually agreed upon with the customer, decreasing possible optimizing flexibility. On the other hand, last-mile logistics is changing as decisions should be made in real time. This paper is focused on the proposed solution of sustainability opportunities in Attended Home Delivery, where we use a new approach to achieve more sustainable deliveries with machine learning forecasts based on real-time data, different dynamic route planning algorithms, tracking logistics events, fleet capacities and other relevant data. The developed model proposes to influence customers to choose a more sustainable delivery time window with important sustainability benefits based on machine learning to predict accurate time windows with real-time data influence. At the same time, better utilization of vehicles, less congestion, and fewer failures at home delivery are achieved. More sustainable routes are selected in the preplanning process due to predicted traffic or other circumstances. Increasing time slots from 2 to 4 h makes it possible to improve travel distance by about 5.5% and decrease cost by 11% if we assume that only 20% of customers agree to larger time slots. Full article

In manufacturing processes using computerized numerical control (CNC) machines, machine tools are operated repeatedly for a long period for machining hard and difficult-to-machine materials, such as stainless steel. These operating conditions frequently result in tool breakage. The failure of machine tools significantly degrades the product quality and efficiency of the target process. To solve these problems, various studies have been conducted for detecting faults in machine tools. However, the most related studies used only the univariate signal obtained from CNC machines. The fault-detection methods using univariate signals have a limitation in that multivariate models cannot be applied. This can restrict in performance improvement of the fault detection. To address this problem, we employed empirical mode decomposition to construct a multivariate dataset from the univariate signal. Subsequently, auto-associative kernel regression was used to detect faults in the machine tool. To verify the proposed method, we obtained a univariate current signal measured from the machining center in an actual industrial plant. The experimental results demonstrate that the proposed method successfully detects faults in the actual machine tools. Full article

The anaerobic digestion of swine manure was performed for more than 2 years in a biogas pilot plant with cereal residues as a mono-input, either by a simple intermittent substrate feeding or by feeding with an automated “autopilot” system under the direction of a Fuzzy logic control (FLC) system, working with a closed-loop feedback control. The pilot plant of the University of Applied Sciences in Nordhausen consisted of a 2.5 m³ dosage tank, a 2.5 m³ digestate tank, and a 1 m³ biogas reactor. Only three control parameters were used for FLC: pH, methane %, and the specific gas production rate (GPR) related to the organic loading rate (OLR), that is GPR/OLR m³ biogas/(kg_VS d), vs = volatile solids. The specific GPR was referred to the OLR of the last feeding every 8 h in terms of kg_VS/(m³ d). In test period I without an FLC system, a safe process with just an OLR of 4 kg_VS/(m³ d) was reached, followed by an overloading and reactor disturbance at ≤6.3 kg_VS/(m³ d) as indicated by acidification with volatile fatty acids up to 25,000 mg/L. However, test period II (585 trial days) with an integrated FLC system allowed a safe OLR up to 11 kg_VS/(m³ d). Apparently, the microbes themselves directed the speed of substrate feeding by the dynamics of their substrate turnover and by the closed loop feedback control, while the three FLC parameters prevented acidification. Therefore, the application of FLC enabled a doubling of the throughput for a biogas reactor in the same time with a ‘turbo speed’. The concomitant hydraulic residence time (HRT) of only 10 days reduced the stirring and heating costs. The usage of an FLC system should open the door for networked biogas production to enable flexible biogas production on demand. Full article