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Processes, Volume 10, Issue 5 (May 2022) – 245 articles

Cover Story (view full-size image): This study presents the development of the washcoating of Ni/boehmite gels, prepared by the sol–gel process, onto the surface of a commercial ceramic honeycomb monolith. It was observed that the deposition of a Ni/boehmite gel led to the formation of a coating. Different morphologies were observed, and defects were highlighted as cracks, coating-free areas, or aggregates. The use of a mixed slurry of calcined alumina particles and colloidal boehmite appeared beneficial, leading to a better resistance of the coating against the stresses induced during drying as well as a deviation in the cracks in the gels by slurry grains. View this paper
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Article
Adaptive Control of Advanced G-L Fuzzy Systems with Several Uncertain Terms in Membership-Matrices
Processes 2022, 10(5), 1043; https://doi.org/10.3390/pr10051043 - 23 May 2022
Viewed by 393
Abstract
In this paper, a set of novel adaptive control strategies based on an advanced G-L (proposed by Ge-Li-Tam, called GLT) fuzzy system is proposed. Three main design points can be summarized as follows: (1) the unknown parameters in a nonlinear dynamic system are [...] Read more.
In this paper, a set of novel adaptive control strategies based on an advanced G-L (proposed by Ge-Li-Tam, called GLT) fuzzy system is proposed. Three main design points can be summarized as follows: (1) the unknown parameters in a nonlinear dynamic system are regarded as extra nonlinear terms and are further packaged into so-called nonlinear terms groups for each equation through the modeling process, which reduces the complexity of the GLT fuzzy system; (2) the error dynamics are further rearranged into two parts, adjustable membership function and uncertain membership function, to aid the design of the controllers; (3) a set of adaptive controllers change with the estimated parameters and the update laws of parameters are provided following the current form of error dynamics. Two identical nonlinear dynamic systems based on a Quantum-CNN system (Q-CNN system) with two added terms are employed for simulations to demonstrate the feasibility as well as the effectiveness of the proposed fuzzy adaptive control scheme, where the tracking error can be eliminated efficiently. Full article
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Article
Valuable Biodiesel Catalyst from Solvay Wastewater
Processes 2022, 10(5), 1042; https://doi.org/10.3390/pr10051042 - 23 May 2022
Viewed by 314
Abstract
Biodiesel is considered a renewable, green fuel as it is derived from renewable living resources like animal fats or vegetable oils. This research is utilized to investigate the possibility of using Solvay wastewater as a source of biodiesel catalyst, which is CaO. CaCl [...] Read more.
Biodiesel is considered a renewable, green fuel as it is derived from renewable living resources like animal fats or vegetable oils. This research is utilized to investigate the possibility of using Solvay wastewater as a source of biodiesel catalyst, which is CaO. CaCl2 from Solvay wastewater reacts with CO2 to produce CaCO3. CaCO3 is then heated to produce pure CaO. Waste cooking oil, wastewater, and CO2, which are considered dangerous materials to the environment, are used to produce valuable products. This research has environmental and economic benefit benefits of using waste materials as a replacement for raw materials. The selected experimental parameters for the CaCO3 production step are stirring rate (500–1300) rpm, CO2 gas flow rate (900–2000) mL/min, amount of ammonia (15–35) mL, and glycerol volume (0–25) mL. The selected experimental parameters for the biodiesel production step are reaction time (2–6) h, methanol to oil ratio (9–15), catalyst loading (1–5) %, and reaction temperature (50–70) °C. The impact of reaction parameters on reaction responses was assessed using the response surface methodology technique. A formula that represents the reaction response as a function of all the independent factors has been created. The optimization of the process is done in two steps: the first one is for the CaCO3 process while the second one is biodiesel production optimization. The first optimization was done to get the CaCO3 with minimum particle size and yield. The second optimization was done to get the maximum amount of biodiesel using minimum energy and low reaction conditions. Process optimization resulted in another economic benefit for this research. The resulted biodiesel yield equals 95.8% biodiesel yield at 2 h reaction time, 15:1 molar ratio of methanol to oil, 56 °C reaction temperature, and 1% catalyst loading. Full article
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Review
Emerging Pollutants in Wastewater, Advanced Oxidation Processes as an Alternative Treatment and Perspectives
Processes 2022, 10(5), 1041; https://doi.org/10.3390/pr10051041 - 23 May 2022
Viewed by 507
Abstract
Emerging pollutants are present in wastewaters treated by conventional processes. Due to water cycle interactions, these contaminants have been reported in groundwater, surface water, and drinking waters. Since conventional processes cannot guarantee their removal or biotransformation, it is necessary to study processes that [...] Read more.
Emerging pollutants are present in wastewaters treated by conventional processes. Due to water cycle interactions, these contaminants have been reported in groundwater, surface water, and drinking waters. Since conventional processes cannot guarantee their removal or biotransformation, it is necessary to study processes that comply with complete elimination. The current literature review was conducted to describe and provide an overview of the available information about the most significant groups of emerging pollutants that could potentially be found in the wastewater and the environment. In addition, it describes the main entry and distribution pathways of emerging contaminants into the environment through the water and wastewater cycle, as well as some of the potential effects they may cause to flora, fauna, and humans. Relevant information on the SARS-CoV-2 virus and its potential spread through wastewater is included. Furthermore, it also outlines some of the Advanced Oxidation Processes (AOPs) used for the total or partial emerging pollutants removal, emphasizing the reaction mechanisms and process parameters that need to be considered. As well, some biological processes that, although slow, are effective for the biotransformation of some emerging contaminants and can be used in combination with advanced oxidation processes. Full article
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Article
A New Method of Quantitatively Evaluating Fracability of Tight Sandstone Reservoirs Using Geomechanics Characteristics and In Situ Stress Field
Processes 2022, 10(5), 1040; https://doi.org/10.3390/pr10051040 - 23 May 2022
Viewed by 326
Abstract
This paper studied the fracability of tight sandstone reservoirs by means of incorporating geomechanics properties and surrounding in situ stresses into a new model. The new fracability evaluation model consists of variables such as brittleness index, critical strain energy release rate index, horizontal [...] Read more.
This paper studied the fracability of tight sandstone reservoirs by means of incorporating geomechanics properties and surrounding in situ stresses into a new model. The new fracability evaluation model consists of variables such as brittleness index, critical strain energy release rate index, horizontal stress difference, and minimum horizontal principal stress gradient. The probability of interconnection of a complex fracture network was quantitatively studied by the brittleness index and horizontal principal stress difference index. The probability of obtaining a large stimulated reservoir volume was evaluated by the critical strain energy release rate index and minimum horizontal principal stress gradient which also quantifies conductivity. This model is more capable of evaluating fracability, i.e., it agrees better with the history of production with a high precision and had correlation coefficients (R2) of 0.970 and 0.910 with liquid production of post-fracturing well testing and the average production of six months of post-fracturing, respectively. It is convenient that all model inputs were obtained by means of loggings. Using this model, tight sandstone reservoirs were classified into three groups according to fracability: Frac ≥ 0.3 MPa−1·m for Type-I, 0.22 MPa−1·m ≤ Frac < 0.3 MPa−1·m for Type-II, and Frac < 0.22 MPa−1·m for Type-III. Full article
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Article
Application of the EGSB-CMBR Process to High-Concentration Organic Wastewater Treatment
Processes 2022, 10(5), 1039; https://doi.org/10.3390/pr10051039 - 23 May 2022
Viewed by 352
Abstract
To decrease the cost of wastewater treatment at the plant, the Wuzhou Shenguan Protein Enteric Coating Production Plant designed and built an expanded granular sludge bed (EGSB)-ceramic membrane bioreactor reactor (CMBR) process for treating high-concentration organic wastewater with a capacity of 25 m [...] Read more.
To decrease the cost of wastewater treatment at the plant, the Wuzhou Shenguan Protein Enteric Coating Production Plant designed and built an expanded granular sludge bed (EGSB)-ceramic membrane bioreactor reactor (CMBR) process for treating high-concentration organic wastewater with a capacity of 25 m3/d. The EGSB is divided into anaerobic and microaerobic sections. The purpose of the anaerobic section is to substantially degrade COD, and the main functions of the microaerobic section are to coordinate the relationship between hydrolytic acid-producing bacteria, methanogenic bacteria (MBP), and sulfate-reducing bacteria (SRB) and to mitigate the inhibitory effects between them to simultaneously remove COD and sulfate. Anaerobic ammonia-oxidizing bacteria were added to the CMBR reactor to remove both COD and ammonia nitrogen. The results of the operation showed that more than 99% of the COD was removed by the EGSB-CMBR process, while the removal rates of NH4+-N and SS were greater than 70% and 90%, respectively. In addition, the effluent met the requirements of the secondary standard of the Comprehensive Wastewater Discharge Standard (8978-1996). Economic and technical analyses showed that the modified EGSB-CMBR reactor has a high treatment efficiency, which greatly saves on the cost of the “commissioned treatment” of high-concentration organic waste liquid in the plant. Specifically, it can save more than 800,000 CNY for the plant annually. Full article
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Article
Micro-Encapsulation and Characterization of Anthocyanin-Rich Raspberry Juice Powder for Potential Applications in the Food Industry
Processes 2022, 10(5), 1038; https://doi.org/10.3390/pr10051038 - 23 May 2022
Viewed by 430
Abstract
Raspberry juice obtained from fresh raspberry fruits was encapsulated separately using gum Arabic (GA), maltodextrin (MT), and waxy starch (WS) (1:10, w/v) and freeze-dried to develop raspberry juice powders (RBJP). The powders were characterised based on their physicochemical and phytochemical [...] Read more.
Raspberry juice obtained from fresh raspberry fruits was encapsulated separately using gum Arabic (GA), maltodextrin (MT), and waxy starch (WS) (1:10, w/v) and freeze-dried to develop raspberry juice powders (RBJP). The powders were characterised based on their physicochemical and phytochemical composition and their rheological and antioxidative properties, which significantly varied among the carriers. GA- and MT-encapsulated RBJP exhibited a better colour, higher yield, oil holding capacity, total anthocyanin content, and antioxidant properties. WS-encapsulated powder showed a better water holding capacity and total phenolic content; however, the powder was characterised by low solubility, total soluble solids, and redness. Hygroscopicity and titratable acidity did not significantly (p > 0.05) vary among the powders. Cyanidin diglucoside, the main anthocyanin compound identified in the RBJP, was significantly higher in MT (2549.89 µg/g) compared to GA (1935.45 µg/g) and WS (1458.81 µg/g). The RBJP produced using MT and GA showed irregular-shaped and non-spherical particles, which were less agglomerated and relatively larger, while the WS powder exhibited more uniform, spherical particles, which agglomerated together. An X-ray diffraction analysis showed that GA and MT powders had an amorphous structure with minimum crystallinity, while RBJP from WS was crystalline. It can be concluded that GA and MT produced RBJP with quality attributes relevant to the food industry. Full article
(This article belongs to the Special Issue Study on Processing and Biological Activity of Functional Foods)
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Article
Molecular Analysis of Soil Bacterial Community Structures for Environmental Risk Assessment with Varieties of Genetically Modified Soybean and Hot Pepper
Processes 2022, 10(5), 1037; https://doi.org/10.3390/pr10051037 - 23 May 2022
Viewed by 295
Abstract
With the advance in gene technology, genetically modified (GM) crops have increased in recent years. GM crops offer us various benefits. However, there are potential risks of GM crops for the environment. In this study, the impacts of transgenic plants on soil microbial [...] Read more.
With the advance in gene technology, genetically modified (GM) crops have increased in recent years. GM crops offer us various benefits. However, there are potential risks of GM crops for the environment. In this study, the impacts of transgenic plants on soil microbial community structures were assessed. Two varieties of soybean (Glycine max L.) and hot pepper (Capsicum annuum L.), which introduced the herbicide-resistant gene, bar, were used in this study. The effects of GM crops on soil microbial community structures were investigated using a cultural method, the denaturing gradient gel electrophoresis (DGGE) procedure, and 16S rRNA gene sequencing on the Illumina platform. Additionally, the persistence of transgenes was monitored using a quantitative real-time PCR procedure. The cultural method, DGGE analysis, and the amplicon-based community profile indicated that soil microbial communities were not significantly different between GM and non-GM lines. The level of the bar gene in GM soybean plots greatly increased when the crops were actively growing, but thereafter gradually decreased to the initial level. Meanwhile, the level of the bar gene in GM hot pepper plots repeatedly increased and decreased according to the flowering stages. These results indicated that soil microbial community structures were not significantly affected. Full article
(This article belongs to the Special Issue The Role of Microorganisms in Environmental Management)
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Article
Multi−Objective Collaborative Optimization Design of Key Structural Parameters for Coal Breaking and Punching Nozzle
Processes 2022, 10(5), 1036; https://doi.org/10.3390/pr10051036 - 23 May 2022
Viewed by 312
Abstract
The technology of coal breaking and punching by a high-pressure water jet can increase the permeability of coal seam and prevent gas explosion accidents. As one of the key components of this technology, the structural parameters of the nozzle have an important effect [...] Read more.
The technology of coal breaking and punching by a high-pressure water jet can increase the permeability of coal seam and prevent gas explosion accidents. As one of the key components of this technology, the structural parameters of the nozzle have an important effect on the performance of the water jet. At present, the relationship between multiple optimization indexes and structural parameters of the nozzle is mostly studied separately. In fact, the influence of the nozzle structural parameters on different optimization indexes is different. When there are multiple optimization indexes, they should be considered collaboratively to achieve the best water jet performance of the nozzle. Therefore, a multi−objective collaborative optimization method is proposed which takes the maximum velocity in X-axis and effective extension distance in Y-axis as the performance evaluation indexes of the water jet. The numerical simulation of the nozzle jet is carried out by computational fluid dynamics(CFD) method, and an orthogonal test database is established. The weight of multi-objective is analyzed, and the key structural parameters of the nozzle are optimized by the combination of BP (back propagation) neural network and genetic algorithms. The results show that the primary and secondary sequence of each structural parameter on is γ>θ>ld, which could reflect the comprehensive influence on the maximum velocity in the X-axis and effective extension distance in the Y-axis. The optimal structural parameters of the nozzle are, θ = 42.512°, l/d = 2.5608, γ = 12.431°. The field erosion experiment shows that compared with the original nozzle, the water jet performance of the optimized nozzle has been improved, the punching depth has been increased by 72.71%, and the punching diameter has been increased by 106.72%. This study provides a certain reference for the design and optimization of coal breaking and punching nozzle. Full article
(This article belongs to the Special Issue Intelligent Control and Maintenance of Fluid Component and System)
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Review
Beyond the Exploration of Muicle (Justicia spicigera): Reviewing Its Biological Properties, Bioactive Molecules and Materials Chemistry
Processes 2022, 10(5), 1035; https://doi.org/10.3390/pr10051035 - 23 May 2022
Viewed by 456
Abstract
In recent years, the research community is tremendously investigating unexplored plants and herbals as they represent a potential source of various biomolecules, which not only contribute to nutrition but also to human health. In fact, Muicle (Justicia spicigera) has attracted the [...] Read more.
In recent years, the research community is tremendously investigating unexplored plants and herbals as they represent a potential source of various biomolecules, which not only contribute to nutrition but also to human health. In fact, Muicle (Justicia spicigera) has attracted the attention of scientists thanks to its multiple biological activities associated with the phytochemicals and specific biomolecules present in this plant. In this review, an evidence on current development works assaying the potential biological properties of Muicle is given. Here, we introduce the key biologically active molecules ascribed to such properties, along with the mechanism of action and interaction. Although the utilization of this plant has been majorly focused on traditional medicine, specific applications in terms of production of new feedstocks and nanomaterials, and developments of functional foods and formulations, are also a current direction towards the exploitation of this natural source. Therefore, this review reports the main outcomes of current research towards the utilization of biomolecules and other elements of the plant in new fields of research such as materials chemistry. Full article
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Article
Machine-Learning-Assisted Prediction of Maximum Metal Recovery from Spent Zinc–Manganese Batteries
Processes 2022, 10(5), 1034; https://doi.org/10.3390/pr10051034 - 23 May 2022
Viewed by 366
Abstract
Spent zinc–manganese batteries contain heavy toxic metals that pose a serious threat to the environment. Recovering these metals is vital not only for industrial use but also for saving the environment. Recycling metal from spent batteries is a complex task. In this study, [...] Read more.
Spent zinc–manganese batteries contain heavy toxic metals that pose a serious threat to the environment. Recovering these metals is vital not only for industrial use but also for saving the environment. Recycling metal from spent batteries is a complex task. In this study, machine-learning-based predictive models are developed for predicting metal recovery from spent zinc–manganese batteries by studying the energy substrates concentration, pH control of bioleaching media, incubating temperature and pulp density. The main objective of this study is to make a detailed comparison among five machine learning models, namely, linear regression, random forest regression, AdaBoost regression, gradient boosting regression and XG boost regression. All the machine learning models are tuned for optimal hyperparameters. The results from each of the machine learning models are compared using several statistical metrics such as R2, mean squared error (MSE), mean absolute error (MAE), maximum error and median error. The XG Boost regression model is observed to be the most effective among the tested algorithms. Full article
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Article
Numerical Simulation and Experimental Test of the Sliding Core Dynamics of a Pressure Controlled Jet Crushing Tool for Natural Gas Hydrate Exploitation
Processes 2022, 10(5), 1033; https://doi.org/10.3390/pr10051033 - 23 May 2022
Viewed by 402
Abstract
A pressure-controlled jet crushing tool (PJCT) for the exploitation of deep-sea natural gas hydrate (NGH) was invented to achieve sediment crushing and cavity creation. The opening and closing of tool is controlled by changing the internal flow rate remotely. It can realize the [...] Read more.
A pressure-controlled jet crushing tool (PJCT) for the exploitation of deep-sea natural gas hydrate (NGH) was invented to achieve sediment crushing and cavity creation. The opening and closing of tool is controlled by changing the internal flow rate remotely. It can realize the controllable continuous switching of the working state between horizontal well drilling and cavity creation. A dynamic simulation model of the sliding core was established based on the innovative design scheme of the PJCT and the motion law of its slide core was analyzed under the influence of spring stiffness, friction coefficient, and flow rate loading scheme. Moreover, an engineering prototype of the PJCT was manufactured so that a sliding core motion experiment of the prototype was carried out. When the drilling fluid flow rate reaches 455 L/min, the PJCT can stably complete the self-locking and unlocking functions. Its sliding core needs more time to stabilize with an increase in spring stiffness. Meanwhile, the PJCT could achieve continuous fast switching between the mechanical drilling state and the jet crushing state within a cycle of continuous flow changes. Finally, the kinematic and dynamic working mechanism of the PJCT is verified by the combination of the numerical simulation and the experimental analysis above. Full article
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Article
Nitric Oxide Generation in N2-Diluted H2–N2O Flames: A Computational Study
Processes 2022, 10(5), 1032; https://doi.org/10.3390/pr10051032 - 22 May 2022
Viewed by 442
Abstract
A computational study was conducted on the addition of nitrogen (0–60 vol%) to stoichiometric hydrogen–nitrous oxide flames at various initial pressures (1–10 bar) and temperatures (300–500 K), with a special emphasis on NO, which is a major pollutant that is generated by these [...] Read more.
A computational study was conducted on the addition of nitrogen (0–60 vol%) to stoichiometric hydrogen–nitrous oxide flames at various initial pressures (1–10 bar) and temperatures (300–500 K), with a special emphasis on NO, which is a major pollutant that is generated by these flames. The detailed kinetic modeling of H2–N2O–N2 flames, which was performed using the GRI 3.0 mechanism, produced the structure of the H2–N2O–N2 flames for the temperature and mass fraction profiles of 53 species, which participated in 325 elementary reactions. The NO profiles that were computed by the detailed kinetic modeling followed the trend of experimental NO profiles that have been reported in the literature for laminar premixed flames at sub-atmospheric pressures. For the examined H2–N2O–N2 flames, an increase in initial pressure resulted in a significant reduction in the NO mass fraction of the burned gas. The increase in initial temperature was also accompanied by an increase in the mass fractions of the generated NO, as well as the flame temperature. Full article
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Article
Laboratory Research on Design of Three-Phase AC Arc Plasma Pyrolysis Device for Recycling of Waste Printed Circuit Boards
Processes 2022, 10(5), 1031; https://doi.org/10.3390/pr10051031 - 22 May 2022
Viewed by 578
Abstract
Accumulation of electronic waste (e-waste) will place a heavy burden on the environment without proper treatment; however, most ingredients contained in it are useful, and it could bring great economic benefits when recycled. A three-phase alternating current (AC) arc plasma pyrolysis device was [...] Read more.
Accumulation of electronic waste (e-waste) will place a heavy burden on the environment without proper treatment; however, most ingredients contained in it are useful, and it could bring great economic benefits when recycled. A three-phase alternating current (AC) arc plasma pyrolysis device was designed for resourcing treatment of waste printed circuit boards (WPCBs). This paper focuses on the analysis of plasma pyrolysis gas products, and the results showed that the plasma could operate stably, and overcame the problems of the poor continuity and low energy of single-arc discharge. Air-plasma would generate NOx contaminants, burn the organics, and oxidize the metals; therefore, air had not been selected as a working gas. Ar-plasma can break the long chains of organic macromolecules to make a combustible gas. Moreover, the strong adhesion between the metals and fiberglass boards would be destroyed, which facilitates subsequent separation. Ar/H2-plasma promoted the decrease of carbon dioxide and the increase of combustible small molecular hydrocarbons in the pyrolysis product compared with Ar-plasma, and the increase of the H2 flow rate or plasma power intensified that promotion effect. The percentage of other components, except the hydrogen of CO2, CO, CH4, C2H4, and C3H6, accounted for 55.7%, 34.2%, 5.6%, 4.5%, and 0% in Ar-plasma, and changed to 35.0%, 29.0%, 11.2%, 24.3%, and 0.5% in Ar/H2-plasma. Ar/H2-plasma could provide a highly chemically active species and break chemical bonds in organic macromolecules to produce small molecules of combustible gas. This laboratory work presents a novel three-phase AC arc plasma device and a new way for recycling WPCBs with high value. Full article
(This article belongs to the Special Issue Advances in Solid Waste Treatment and Design)
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Article
Machine Learning Methods to Identify Predictors of Psychological Distress
Processes 2022, 10(5), 1030; https://doi.org/10.3390/pr10051030 - 22 May 2022
Viewed by 407
Abstract
As people pay ever-increasing attention to the problems caused by psychological stress, research on its influencing factors becomes crucial. This study analyzed the Health Information National Trends Survey (HINTS, Cycle 3 and Cycle 4) data (N = 5484) and assessed the outcomes using [...] Read more.
As people pay ever-increasing attention to the problems caused by psychological stress, research on its influencing factors becomes crucial. This study analyzed the Health Information National Trends Survey (HINTS, Cycle 3 and Cycle 4) data (N = 5484) and assessed the outcomes using descriptive statistics, Chi-squared tests, and t-tests. Four machine learning algorithms were applied for modeling: logistic regression (linear), random forests (RF) (ensemble), the artificial neural network (ANN) (nonlinear), and gradient boosting (GB) (ensemble). The samples were randomly assigned to a 50% training set and a 50% validation set. Twenty-six preselected variables from the databases were used in the study as predictors, and the four models identified twenty predictors of psychological distress. The essence of this paper is a binary classification problem of judging whether an individual has psychological distress based on many different factors. Therefore, accuracy, precision, recall, F1-score, and AUC were used to evaluate the model performance. The logistic regression model selected predictors by forward selection, backward selection, and stepwise regression; variable importance values were used to identify predictors in the other three machine learning methods. Of the four machine learning models, the ANN exhibited the best predictive effect (AUC = 73.90%). A range of predictors of psychological distress was identified by combining the four machine learning models, which would help improve the performance of the existing mental health screening tools. Full article
(This article belongs to the Special Issue Application of Artificial Intelligence in Industry and Medicine)
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Article
Improvement of As(V) Adsorption by Reduction of Granular to Micro-Sized Ferric Hydroxide
Processes 2022, 10(5), 1029; https://doi.org/10.3390/pr10051029 - 22 May 2022
Viewed by 422
Abstract
The remediation of groundwater containing arsenic is a problem that has been addressed using adsorption processes with granulated materials in columns, but the remediation itself could be improved by using micro-sized adsorbents in stirred systems. In this study, arsenate (As(V)) batch adsorption experiments [...] Read more.
The remediation of groundwater containing arsenic is a problem that has been addressed using adsorption processes with granulated materials in columns, but the remediation itself could be improved by using micro-sized adsorbents in stirred systems. In this study, arsenate (As(V)) batch adsorption experiments were performed using granular ferric hydroxide (GFH) and two derived micro-sized materials. Reduced-size adsorbents were produced by energetic ball milling, giving final sizes of 0.1–2 µm (OF-M samples) and ultra-sonication, producing final sizes of 2–50 µm (OF-U samples). Equilibrium isotherm studies showed that the Langmuir model was a good fit for the three sorbents, with the highest maximum adsorption capacity (qmax) for OF-U and the lowest for OF-M. The adsorption of the two groundwater samples occurred according to the obtained equilibrium isotherms and indicated the absence of interfering agents for the three adsorbents. Batch kinetics tests in stirred beakers followed a pseudo second-order model and indicated that the kinetics of the OF-U sorbent was faster than the kinetics of the GFH sorbent. The tests also showed an increase in the qe values for the reduced-size sorbent. The application of ultrasonication to the GFH produced an increase of 23 % in the qmax and b term and an increase of 34-fold for the kinetic constant (k2) in the stirred batch systems tested. These results suggest that this new approach, based on ultra-sonication, has the potential for improving the adsorption of arsenic in groundwater. Full article
(This article belongs to the Special Issue Novel Adsorbent for Environmental Remediation)
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Article
Integration of an Absorption Chiller to a Process Applying the Pinch Analysis Approach
Processes 2022, 10(5), 1028; https://doi.org/10.3390/pr10051028 - 21 May 2022
Viewed by 331
Abstract
In addition to the consumption of hot utilities, there is also a significant cost associated with the consumption of cold utilities when there is a high demand for cooling. A promising solution for cooling is an absorption chiller (AC), which uses heat instead [...] Read more.
In addition to the consumption of hot utilities, there is also a significant cost associated with the consumption of cold utilities when there is a high demand for cooling. A promising solution for cooling is an absorption chiller (AC), which uses heat instead of electricity for cooling. A thermodynamic approach for evaluating AC integrated with a process is presented in this work. A model for assessing the properties and duties of an AC cycle was developed. The integration of a combined process-AC system was evaluated using the Grand Composite Curve. Three different options of integration were analyzed: (i) above the Pinch, (ii) below the Pinch, and (iii) across the Pinch. AC represents the combined effect of a heat engine and a heat pump, as the generator together with the absorber and condenser has the function of a heat engine, while the evaporator combined with the absorber and condenser mimics the function of a heat pump. The comparison between the non-integrated and integrated process-AC systems has revealed that the proper placement of AC is across or below the Pinch and the improper is above the Pinch. If AC was entirely integrated below the Pinch, the integration would result in a complete (100%) reduction in the consumption of hot utility for the operation of AC. The most suitable placement of AC with double reduction of hot utility consumption and complete reduction of both hot and cold utility to operate AC is across the Pinch due to the pumping of heat through AC from below to above the Pinch. Full article
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Article
An Experimental and Modeling Combined Approach in Preparative Hydrophobic Interaction Chromatography
Processes 2022, 10(5), 1027; https://doi.org/10.3390/pr10051027 - 20 May 2022
Viewed by 467
Abstract
Chromatography is a technique widely used in the purification of biopharmaceuticals, and generally consists of several chromatographic steps. In this work, Hydrophobic Interaction Chromatography (HIC) is investigated as a polishing step for the purification of therapeutic proteins. Adsorption mechanisms in hydrophobic interaction chromatography [...] Read more.
Chromatography is a technique widely used in the purification of biopharmaceuticals, and generally consists of several chromatographic steps. In this work, Hydrophobic Interaction Chromatography (HIC) is investigated as a polishing step for the purification of therapeutic proteins. Adsorption mechanisms in hydrophobic interaction chromatography are still not completely clear and a limited amount of published data is available. In addition to new data on adsorption isotherms for some proteins (obtained both by high-throughput and frontal analysis method), and a comparison of different models proposed in the literature, two different approaches are compared in this work to investigate HIC. The predictive approach exploits an in-house code that simulates the behavior of the component in the column using the model parameters found from the fitting of experimental data. The estimation approach, on the other hand, exploits commercial software in which the model parameters are found by the fitting of a few experimental chromatograms. The two approaches are validated on some bind-elute runs: the predictive approach is very informative, but the experimental effort needed is high; the estimation approach is more effective, but the knowledge gained is lower. The second approach is also applied to an in-development industrial purification process and successfully resulted in predicting the behavior of the system, allowing for optimization with a reduction in the time and amount of sample needed. Full article
(This article belongs to the Special Issue Applications of Chromatography in Drug Analysis and Development)
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A Method to Derive the Characteristic and Kinetic Parameters of 1,1-Bis(tert-butylperoxy)cyclohexane from DSC Measurements
Processes 2022, 10(5), 1026; https://doi.org/10.3390/pr10051026 - 20 May 2022
Viewed by 337
Abstract
A differential scanning calorimetry (DSC) experiment was carried out to determine the thermal characteristics of harmful substances. Most experimenters only use the results of measurement and rarely conduct in-depth research on the variety of information behind the measurement. This study used Wolfram’s Mathematica [...] Read more.
A differential scanning calorimetry (DSC) experiment was carried out to determine the thermal characteristics of harmful substances. Most experimenters only use the results of measurement and rarely conduct in-depth research on the variety of information behind the measurement. This study used Wolfram’s Mathematica as a DSC measurement research tool to plot the peak curve and derive the characteristic parameters graphically for 1,1-Bis(tert-butylperoxy)cyclohexane. The research steps included raw data cleansing, peak curve normalization, characteristic parameter derivation, and total reaction heat calculation. The kinetic parameters of individual data were derived through the Borchardt and Daniels method, and the autocatalytic model was also verified. We applied the derived characteristic parameters to simulate the peak curve through the Gaussian curve model, which can be used for estimating the peak curve of other heating rates. The derived kinetic parameters were used to observe the effects on the peak curve. The simulation can be used to plan the test results at other rates in a similar temperature range and can also be used to explore the influence of different kinetic parameters on the configuration of the shape of the peak curve and a preliminary model test of materials for materials DSC research. Full article
(This article belongs to the Special Issue Chemical Process Modelling and Simulation)
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Review
Membrane Chromatography and Fractionation of Proteins from Whey—A Review
Processes 2022, 10(5), 1025; https://doi.org/10.3390/pr10051025 - 20 May 2022
Viewed by 345
Abstract
Membrane chromatography (MC) is an emerging bioseparation technology combining the principles of membrane filtration and chromatography. In this process, one type of molecule is adsorbed in the stationary phase, whereas the other type of molecule is passed through the membrane pores without affecting [...] Read more.
Membrane chromatography (MC) is an emerging bioseparation technology combining the principles of membrane filtration and chromatography. In this process, one type of molecule is adsorbed in the stationary phase, whereas the other type of molecule is passed through the membrane pores without affecting the adsorbed molecule. In subsequent the step, the adsorbed molecule is recovered by an elution buffer with a unique ionic strength and pH. Functionalized microfiltration membranes are usually used in radial flow, axial flow, and lateral flow membrane modules in MC systems. In the MC process, the transport of a solute to a stationary phase is mainly achieved through convection and minimum pore diffusion. Therefore, mass transfer resistance and pressure drop become insignificant. Other characteristics of MC systems are a minimum clogging tendency in the stationary phase, the capability of operating with a high mobile phase flow rate, and the disposable (short term) application of stationary phase. The development and application of MC systems for the fractionation of individual proteins from whey for investigation and industrial-scale production are promising. A significant income from individual whey proteins together with the marketing of dairy foods may provide a new commercial outlook in dairy industry. In this review, information about the development of a MC system and its applications for the fractionation of individual protein from whey are presented in comprehensive manner. Full article
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Article
Logistics Service Provider Evaluation and Selection: Hybrid SERVQUAL–FAHP–TOPSIS Model
Processes 2022, 10(5), 1024; https://doi.org/10.3390/pr10051024 - 20 May 2022
Viewed by 384
Abstract
Production and business enterprises are aiming to improve their logistics activities in order to increase competitiveness. Therefore, the criteria and decision support models for selecting logistics service providers are significant to businesses. Fuzzy theory has been applied to almost all industrial engineering fields, [...] Read more.
Production and business enterprises are aiming to improve their logistics activities in order to increase competitiveness. Therefore, the criteria and decision support models for selecting logistics service providers are significant to businesses. Fuzzy theory has been applied to almost all industrial engineering fields, such as decision making, operations research, quality control, project scheduling and many more. In this research, the authors combined fuzzy theory and a Multicriteria Decision Making (MCDM) model for the evaluation and selection of potential third-party logistics (3PL) providers. The goal is to take the advantages of these approaches and allow for more accurate and balanced (symmetric) decision making through their integration. The main contribution of this study is that it develops a complete approach to assessing the quality of the logistics service industry. The combined method of the SERVQUAL and FAHP–TOPSIS models not only provides reasonable results, but it also allows decision makers to visualize the impact of different criteria on the final outcome. Furthermore, this integrated model can provide valuable insights and methods for other areas to define service quality. Full article
(This article belongs to the Special Issue Optimization Algorithms Applied to Sustainable Production Processes)
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Article
Correlation between the Desiccator Method and 1 m³ Climate Chamber Method for Measuring Formaldehyde Emissions from Veneered Particleboard
Processes 2022, 10(5), 1023; https://doi.org/10.3390/pr10051023 - 20 May 2022
Viewed by 292
Abstract
To shorten the measuring time of formaldehyde emissions from wood-based panels and reduce the costs of quality control processes during industrial furniture production, more efficient methods for measuring formaldehyde emissions from wood-based panels need to be developed. In this study, the formaldehyde emissions [...] Read more.
To shorten the measuring time of formaldehyde emissions from wood-based panels and reduce the costs of quality control processes during industrial furniture production, more efficient methods for measuring formaldehyde emissions from wood-based panels need to be developed. In this study, the formaldehyde emissions from 18-mm-thick veneered particleboard were measured using the desiccator method and the 1 m3 climate chamber method according to Chinese national standard GB/T17657-2013, and the correlation between these two methods was determined. Through a correlation analysis of 60 groups of data, the results indicated that the linear correlation coefficient (R) between two methods was 0.718, and the regression model was established, which by F and P values demonstrated a significant correlation at the 0.01 level of significance. As long as the quality of materials and the production processes remained consistent, the desiccator method was reliable enough for conducting routine quality control measurements of formaldehyde emissions from veneered boards of 18 mm thickness. In case of dispute, the results can be verified using the 1 m3 climate chamber method for accuracy. Full article
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Article
Study of Oxidation of Ciprofloxacin and Pefloxacin by ACVA: Identification of Degradation Products by Mass Spectrometry and Bioautographic Evaluation of Antibacterial Activity
Processes 2022, 10(5), 1022; https://doi.org/10.3390/pr10051022 - 20 May 2022
Viewed by 326
Abstract
The new RP-HPLC-DAD method for the determination of ciprofloxacin and pefloxacin, next to their degradation products after the oxidation reaction with 4,4′-azobis(4-cyanopentanoic acid) (ACVA) was developed. The method was validated according to the guidelines of the International Council for Harmonization of Technical Requirements [...] Read more.
The new RP-HPLC-DAD method for the determination of ciprofloxacin and pefloxacin, next to their degradation products after the oxidation reaction with 4,4′-azobis(4-cyanopentanoic acid) (ACVA) was developed. The method was validated according to the guidelines of the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) and meets the acceptance criteria. The experimental data indicate that the course of the oxidation process depends on the type of fluoroquinolone (FQ), the incubation time and temperature. The performed kinetic evaluation allowed us to state that the oxidation of FQs proceeds according to the second-order kinetics. The degradation products of the FQs were identified using the UHPLC-MS/MS method and their structures were proposed. The results obtained by the TLC-direct bioautography technique allowed us to state that the main ciprofloxacin and pefloxacin oxidation products probably retained antibacterial activity against Escherichia coli. Full article
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Article
Human Dental Pulp Cells form Spheroids in the Presence of Serum When Seeded on a Low-Attachment Cultural Surface
Processes 2022, 10(5), 1021; https://doi.org/10.3390/pr10051021 - 20 May 2022
Viewed by 313
Abstract
Spheroid formation is a characteristic feature of stem/progenitor cells. Under a serum-free cultural condition, human dental pulp cells can form spheroids. In the present study, we report that these cells can also form spheroids in the presence of serum when seeded on a [...] Read more.
Spheroid formation is a characteristic feature of stem/progenitor cells. Under a serum-free cultural condition, human dental pulp cells can form spheroids. In the present study, we report that these cells can also form spheroids in the presence of serum when seeded on a low-attachment cultural surface. Dental pulp cells derived from three teeth were seeded with surface densities 103–105/cm2 in wells of low attachment and standard cultural plates. Fibroblasts were also seeded onto a low-attachment surface as a comparison. The growth of single spheroids of pulp cells was observed for 7 days. Pulp cells in spheroids and cells attached to the low-attachment surface were separated and further expanded on standard cultural surface in the monolayer and studied for their viability and osteogenic differentiation comparatively. In all three cultures of primary human dental pulp cells on low attachment surface, spheroids formed one day after seeding and grew in size over the 7 days of observation. The optimal seeding density for spheroids was around 104 cells/cm2 (105 cells/mL). Expanded pulp cells from the spheroids exhibited lower viability but higher osteogenic differentiation potential compared to pulp cells expanded from those attached to the surface of the low attachment plate. Human dental pulp cells have the specific capacity to forms spheroids when seeded on a low-attachment surface and may enable selection of a subpopulation with stronger differentiation potential and may also provide a strategy for culturing these cells in a three-dimensional organization without scaffolds. Full article
(This article belongs to the Special Issue Advanced Processes Creating New Technologies in Tomorrow's Industry)
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Article
Design and Simulation of Small-Scale Waste Separation and Sorting Equipment
Processes 2022, 10(5), 1020; https://doi.org/10.3390/pr10051020 - 20 May 2022
Viewed by 379
Abstract
Environmental pollution is currently a major concern globally owing to increase in the world population and advances in industrialization. An automatic waste separation and sorting equipment for small-scale waste sorting systems was constructed in this paper. A two-DoF (two-degree-of-freedom) parallel sorting mechanism as [...] Read more.
Environmental pollution is currently a major concern globally owing to increase in the world population and advances in industrialization. An automatic waste separation and sorting equipment for small-scale waste sorting systems was constructed in this paper. A two-DoF (two-degree-of-freedom) parallel sorting mechanism as well as a belt waste separation and feeding mechanism were designed, and 3D models of the mechanism were established. Finite element analysis (FEA) was conducted for the sorting mechanism, and kinematic and dynamic analysis and numerical simulation were performed for the waste and sorting mechanism. The simulation results demonstrated that the spherical waste did not roll out of the platform after leaving the slideway. The waste was stabilized at the center of the platform within a short duration with movement of the collecting mechanism of the platform. The system was optimized to reduce waste separation and sorting time. Stability of the waste motion in the equipment as well as efficiency of the system were significantly improved after optimization. The results showed that the designed equipment can complete separation and sorting of waste materials at lower output power. Full article
(This article belongs to the Special Issue Advances in Solid Waste Treatment and Design)
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Article
Unveiling the Evolution of Madeira Wine Key Metabolites: A Three-Year Follow-Up Study
Processes 2022, 10(5), 1019; https://doi.org/10.3390/pr10051019 - 20 May 2022
Viewed by 389
Abstract
Madeira wine (MW) encompasses an unusual oxidative ageing process that makes it distinctive. Several metabolites have been related to its quality and safety, such as 5-hydroxymethylfurfural (HMF), furfural, sotolon, and ethyl carbamate (EC). These compounds were quantified over a three-year period to assess [...] Read more.
Madeira wine (MW) encompasses an unusual oxidative ageing process that makes it distinctive. Several metabolites have been related to its quality and safety, such as 5-hydroxymethylfurfural (HMF), furfural, sotolon, and ethyl carbamate (EC). These compounds were quantified over a three-year period to assess their formation rate according to the ageing procedure used: canteiro vs. estufagem. Estufagem, which includes thermal processing of young MWs, promoted greater HMF, furfural, and sotolon accumulation, especially in sweet wines, in which sotolon contributed significantly to aroma (odour active values up to 17.5). Tinta Negra revealed a higher predisposition to form EC while Malvasia and Sercial were less prone to its formation. The formation of furfural, HMF, and EC strongly correlated with the ageing time. Sotolon had a strong correlation with the ageing time in canteiro (r = 0.79) and a moderate correlation in estufagem (r = 0.65). In both ageing procedures, sotolon, furfural, and HMF formation trends strongly correlated with each other (r = 0.74–0.90). In turn, EC also correlated with all furans (r = 0.51–0.85). Yellow tones (b*) correlated with these metabolites only when wines undergo estufagem. This study provides valuable insights to improve MW quality and safety management procedures. Full article
(This article belongs to the Special Issue Emerging Trends in the Wine Ageing Process)
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Article
An Effective Temperature Control Method for Dividing-Wall Distillation Columns
Processes 2022, 10(5), 1018; https://doi.org/10.3390/pr10051018 - 20 May 2022
Viewed by 387
Abstract
Temperature control is widely perceived to be superior to direct composition control for the control of dividing-wall distillation columns (DWDCs) due to its advantages in dynamic characteristics. However, because of the limited estimation accuracy to the controlled product purities, the former cannot eliminate [...] Read more.
Temperature control is widely perceived to be superior to direct composition control for the control of dividing-wall distillation columns (DWDCs) due to its advantages in dynamic characteristics. However, because of the limited estimation accuracy to the controlled product purities, the former cannot eliminate the steady-state errors in the maintained product purities as completely as the latter. In order to reduce the steady-state deviations in the maintained product purities, an effective temperature control method is proposed in the current article by means of a kind of simple but effective product quality estimator (PQE). For the proposed PQE, temperatures of three stages located in the controlled column section (TI1, TI2, and TI3) are employed as inputs, and a linear sum of these three inputted stage temperatures (α × TI1 + β × TI2 + γ × TI3) is given as output. A genetic algorithm with an elitist preservation strategy is used to optimize the locations of the three stage temperatures and the values of α, β, and γ to ensure the estimation accuracy of the PQE. Concerning the controls of two DWDCs, i.e., one Petlyuk DWDC separating an ethanol/propanol/butanol ternary mixture and one Kaibel DWDC separating a methanol/ethanol/propanol/butanol quaternary mixture, the effectiveness of the PQE is assessed through comparing the performance of the temperature inferential control scheme using the PQE and the double temperature difference control scheme. According to the dynamic simulation results obtained, the former control scheme displays not only smaller steady-state deviations in the maintained product purities, but also better dynamic characteristics as compared with the latter control scheme. This result fully demonstrates that the proposed PQE can be a useful tool for the temperature inferential control of the DWDC. Full article
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Article
Hydrogen Storage Behavior and Performance of Multiple Cold-Rolled MgH2/Nb2O5 Nanocomposite Powders
Processes 2022, 10(5), 1017; https://doi.org/10.3390/pr10051017 - 19 May 2022
Viewed by 344
Abstract
The global interest in MgH2 is due to the natural availability of Mg and its capacity to retain hydrogen at a concentration of up to 7.60 wt.%. Despite its appealing characteristics and ease of production on an industrial scale at ambient temperature [...] Read more.
The global interest in MgH2 is due to the natural availability of Mg and its capacity to retain hydrogen at a concentration of up to 7.60 wt.%. Despite its appealing characteristics and ease of production on an industrial scale at ambient temperature using the reactive ball milling (RBM) technique, MgH2 is a highly stable chemical with sluggish hydrogenation and dehydrogenation rates below 300 °C. Among the different methods used to improve the hydrogenation/dehydrogenation kinetic behavior of MgH2, mechanical treatment and/or catalysis are regarded to be the most effective methods. The purpose of this research was to explore the effectiveness of several cold rolling (CR) stages on the hydrogenation properties of recycled magnesium rods, as well as the effect of the resulting RBM on the final product. For this process, the as-received waste Mg-rods were firstly cold-rolled 200 times and then remilled under H2 atmosphere for 100 h. The as-RBM powders were then cold-rolled for 100 passes and then ball-milled with 10 and 15 wt.% Nb2O5 powders for 50 h. The results showed that when the materials were subjected to different types of defects (dislocations, stacking faults, and twining) generated by CR and RBM, their gas absorption/desorption kinetics were improved. This was indexed by their ability to achieve a long cycle lifetime at lower temperatures when compared with the as-received materials. The powders were further improved in terms of kinetics and decomposition temperature upon RBM with Nb2O5 for 50 h. The nanocomposite MgH2/10 wt.% and 15 wt.% Nb2O5 exhibit good hydrogen storage capabilities at a comparatively low temperature (225 °C) with a long cycle life that extended from 110 h to 170 h, without serious degradation in storage capacity and kinetics. Full article
(This article belongs to the Section Energy Systems)
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Article
GC–MS-Based Metabolites Profiling, In Vitro Antioxidant, Anticancer, and Antimicrobial Properties of Different Solvent Extracts from the Botanical Parts of Micromeria fruticosa (Lamiaceae)
Processes 2022, 10(5), 1016; https://doi.org/10.3390/pr10051016 - 19 May 2022
Viewed by 340
Abstract
The present study assessed the metabolites and bioactivities of Micromeria fruticosa plant parts extracted with various solvents (ethanol, n-hexane, and water) through the steeping extraction method. Thereafter, the extracts were analyzed using GC-MS. Moreover, the extracts were tested for their antioxidant, antimicrobial, [...] Read more.
The present study assessed the metabolites and bioactivities of Micromeria fruticosa plant parts extracted with various solvents (ethanol, n-hexane, and water) through the steeping extraction method. Thereafter, the extracts were analyzed using GC-MS. Moreover, the extracts were tested for their antioxidant, antimicrobial, and antitumor activities. The quali-quantitative analysis of Micromeria fruticosa crude extracts revealed the occurrence of 27 secondary metabolites. Some major bioactives identified were menthone, oleamide, pulegone, and menthol. Numerous antioxidant minerals, viz., Fe, Zn, and Mn, were present. The water extract of leaves exhibited the highest DPPH scavenging activity (89.73%), followed by the water extract of flowers (80.07%) at 100 μg/mL. The stems’ water extract demonstrated greater antimicrobial activity against all the bacteria species tested. The ethanolic leaf and aqueous stem extracts exhibited strong activity against C. albicans and E. coli. Flowers’ aqueous extract demonstrated the highest cytostatic effect on the colon cell line by reducing viability, followed by the leaves’ ethanol extract. The extraction solvents influenced the recovery of phytocompounds, and the highest pharmacological activities of the different extracts could be correlated to the presence of additional bioactives. Our results suggest that the Micromeria fruticosa plant is a favorable source of natural products with promising properties for potential nutraceutical and functional food applications. Full article
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Article
Interval-Valued Pythagorean Fuzzy Similarity Measure-Based Complex Proportional Assessment Method for Waste-to-Energy Technology Selection
Processes 2022, 10(5), 1015; https://doi.org/10.3390/pr10051015 - 19 May 2022
Viewed by 331
Abstract
This study introduces an integrated decision-making methodology to choose the best “waste-to-energy (WTE)” technology for “municipal solid waste (MSW)” treatment under the “interval-valued Pythagorean fuzzy sets (IPFSs)”. In this line, first, a new similarity measure is developed for IPFSs. To show the utility [...] Read more.
This study introduces an integrated decision-making methodology to choose the best “waste-to-energy (WTE)” technology for “municipal solid waste (MSW)” treatment under the “interval-valued Pythagorean fuzzy sets (IPFSs)”. In this line, first, a new similarity measure is developed for IPFSs. To show the utility of the developed similarity measure, a comparison is presented with some extant similarity measures. Next, a weighting procedure based on the presented similarity measures is proposed to obtain the criteria weight. Second, an integrated approach called the “interval-valued Pythagorean fuzzy-complex proportional assessment (IPF-COPRAS)” is introduced using the similarity measure, linear programming model and the “complex proportional assessment (COPRAS)” method. Furthermore, a case study of WTE technologies selection for MSW treatment is taken to illustrate the applicability and usefulness of the presented IPF-COPRAS method. The comparative study is made to show the strength and stability of the presented methodology. Based on the results, the most important criteria are “greenhouse gas (GHG)” emissions (P3), microbial inactivation efficacy (P7), air emissions avoidance (P9) and public acceptance (P10) with the weight/significance degrees of 0.200, 0.100, 0.100 and 0.100, respectively. The evaluation results show that the most appropriate WTE technology for MSW treatment is plasma arc gasification (H4) with a maximum utility degree of 0.717 followed by anaerobic digestion (H7) with a utility degree of 0.656 over various considered criteria, which will assist with reducing the amount of waste and GHG emissions and also minimize and maintain the costs of landfills. Full article
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Article
Time-Jerk optimal Trajectory Planning of Industrial Robots Based on a Hybrid WOA-GA Algorithm
Processes 2022, 10(5), 1014; https://doi.org/10.3390/pr10051014 - 19 May 2022
Viewed by 303
Abstract
An optimal and smooth trajectory for industrial robots has a positive impact on reducing the execution time in an operation and the vibration in their joints. In this paper, a methodology for the time-optimal and jerk-continuous trajectory planning of industrial robots is proposed. [...] Read more.
An optimal and smooth trajectory for industrial robots has a positive impact on reducing the execution time in an operation and the vibration in their joints. In this paper, a methodology for the time-optimal and jerk-continuous trajectory planning of industrial robots is proposed. The entire trajectory is interpolated in the joint space utilizing fifth-order B-splines and then optimized by a hybrid whale optimization algorithm and genetic algorithm (WOA-GA). Two objective functions, including the integral of the squared jerk along the entire trajectory and the total execution time, are minimized to obtain the optimal entire trajectory. A fifth-order B-spline interpolation technique enables the achievement of a jerk-continuous trajectory, while respecting the kinematic limits of jerk, acceleration and velocity. WOA-GA is utilized to solve the time-jerk optimal trajectory planning problem with nonlinear constraints. The proposed hybrid optimization algorithm yielded good results and achieved the time-jerk optimal trajectory better under kinematic constraints compared to the genetic algorithm, whale optimization algorithm, improved whale optimization algorithm with particle swarm optimization and adaptive cuckoo search algorithm. The numerical results show the competent performances of the proposed methodology to generate trajectories with high smooth curves and short total execution time. Full article
(This article belongs to the Special Issue Big Data in Manufacturing, Biology, Healthcare and Life Sciences)
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