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Volume 9
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Processes, Volume 9, Issue 6 (June 2021) – 178 articles

Cover Story (view full-size image): Agro-industrial wastes and by-products such as animal manures, energy crops and agro-industrial residues are characterized by high biofuels production efficiency. Two-stage anaerobic digestion focuses at simultaneous H2 and CH4 production, providing increased process yields and energy recovery compared to the conventional one-stage anaerobic digestion. The aim of this study was to investigate the effect of pH on dark fermentation of an agro-waste mixture comprised of cheese whey, sweet sorghum stalks and cow manure in order to evaluate H2 production and end-products distribution. The influence of heat-treated inoculum, organic load and ensiled sorghum on H2 production was also tested. View this paper
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11 pages, 2673 KiB  
Article
Understanding the Evolution and Applications of Intelligent Systems via a Tri-X Intelligence (TI) Model
by Min Zhao, Zhenbo Ning, Baicun Wang, Chen Peng, Xingyu Li and Sihan Huang
Processes 2021, 9(6), 1080; https://doi.org/10.3390/pr9061080 - 21 Jun 2021
Cited by 4 | Viewed by 3352
Abstract
The evolution and application of intelligence have been discussed from perspectives of life, control theory and artificial intelligence. However, there has been no consensus on understanding the evolution of intelligence. In this study, we propose a Tri-X Intelligence (TI) model, aimed at providing [...] Read more.
The evolution and application of intelligence have been discussed from perspectives of life, control theory and artificial intelligence. However, there has been no consensus on understanding the evolution of intelligence. In this study, we propose a Tri-X Intelligence (TI) model, aimed at providing a comprehensive perspective to understand complex intelligence and the implementation of intelligent systems. In this work, the essence and evolution of intelligent systems (or system intelligentization) are analyzed and discussed from multiple perspectives and at different stages (Type I, Type II and Type III), based on a Tri-X Intelligence model. Elemental intelligence based on scientific effects (e.g., conscious humans, cyber entities and physical objects) is at the primitive level of intelligence (Type I). Integrated intelligence formed by two-element integration (e.g., human-cyber systems and cyber-physical systems) is at the normal level of intelligence (Type II). Complex intelligence formed by ternary-interaction (e.g., a human-cyber-physical system) is at the dynamic level of intelligence (Type III). Representative cases are analyzed to deepen the understanding of intelligent systems and their future implementation, such as in intelligent manufacturing. This work provides a systematic scheme, and technical supports, to understand and develop intelligent systems. Full article
(This article belongs to the Special Issue Expanding the Horizons of Manufacturing: Towards Wide Integration, Smart Systems and Tools)
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12 pages, 1267 KiB  
Article
A Modification of Palm Waste Lignocellulosic Materials into Biographite Using Iron and Nickel Catalyst
by Noor Hafidzah Jabarullah, Afiqah Samsul Kamal and Rapidah Othman
Processes 2021, 9(6), 1079; https://doi.org/10.3390/pr9061079 - 21 Jun 2021
Cited by 7 | Viewed by 3954
Abstract
This paper presents an alternative way to maximize the utilization of palm waste by implementing a green approach to modify lignocellulosic materials into a highly crystalline biographite. A bio-graphite structure was successfully synthesized by converting lignocellulosic materials via a simple method using palm [...] Read more.
This paper presents an alternative way to maximize the utilization of palm waste by implementing a green approach to modify lignocellulosic materials into a highly crystalline biographite. A bio-graphite structure was successfully synthesized by converting lignocellulosic materials via a simple method using palm kernel shell (PKS) as a carbon precursor. This involved the direct impregnation of a catalyst into raw material followed by a thermal treatment. The structural transformation of the carbon was observed to be significantly altered by employing different types of catalysts and varying thermal treatment temperatures. Both XRD and Raman spectroscopy confirmed that the microstructural alteration occurred in the carbon structure of the sample prepared at 800 and 1000 °C using iron, nickel or the hybrid of iron-nickel catalysts. The XRD pattern revealed a high degree of graphitization for the sample prepared at 1000 °C, and it was evident that iron was the most active graphitization catalyst. The presence of an intensified peak was observed at 2θ = 26.5°, reflecting the formation of a highly ordered graphitic structure as a result of the interaction between the iron catalyst and the thermal treatment process at 1000 °C. The XRD observation was further supported by the Raman spectrum in which PKS-Fe1000 showed a lower defect structure associated with the presence of a significant amount of graphitic structure, as a low value of (Id/Ig) ratio was reported. An HRTEM image showed a well-defined lattice fringe seen on the structure for PKS-Fe1000; meanwhile, a disordered microstructure was observed for the control sample, indicating that successful structural modification was achieved with the aid of the catalyst. Further analysis from BET found that the PKS-Fe1000 developed a surface area of 202.932 m2/g with a pore volume of 0.208 cm3/g. An overall successful modification from palm waste into graphitic material was achieved. Thus, this study will help those involved in waste management to evaluate the possibility of a sustainable process for the generation of graphite material from palm waste. It can be concluded that palm waste is a potential source of production for graphite material through the adoption of the proposed waste management process. Full article
(This article belongs to the Special Issue Circular Economy and Efficient Use of Resources)
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19 pages, 1386 KiB  
Article
An Integrated Kano Model, Fuzzy Analytical Hierarchy Process, and Decision Matrix for Sustainable Supplier Selection in Palm Oil Industries Indonesia, a Case Study
by Tsai-Chi Kuo, Muniroh Muniroh and Kristin Halisa Fau
Processes 2021, 9(6), 1078; https://doi.org/10.3390/pr9061078 - 21 Jun 2021
Cited by 13 | Viewed by 3035
Abstract
Industries have to integrate environmental, social, and economic aspects into their supply chain management to achieve sustainability. Hence, the industry needs to take appropriate actions in choosing the right suppliers. The aim of this study is to develop a framework for selecting sustainable [...] Read more.
Industries have to integrate environmental, social, and economic aspects into their supply chain management to achieve sustainability. Hence, the industry needs to take appropriate actions in choosing the right suppliers. The aim of this study is to develop a framework for selecting sustainable suppliers by integrating quality management tools using the Kano model, Fuzzy Analytical Hierarchy Process, and Decision Matrix Method. To identify the critical sustainability criteria, the Kano model by the clustering the criteria for sustainable selection supplier was used. We then used the Fuzzy Analytical Hierarchy Process to determine the weight of each criterion and applied the Decision Matrix Method to select the most sustainable supplier. Afterward, the appropriate proposed framework was implemented in one of the palm oil industries in Indonesia to validate that the framework is applicable and useful. The study shows that the environmental dimension is the most sustainable supplier criteria followed by economy and social dimension. Quality, pollution control, and information disclosures were found to be important sub-dimensions for sustainable supplier selection. Full article
(This article belongs to the Special Issue Green Supply Chain Management (GSCM): Design, Planning and Optimization)
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15 pages, 2732 KiB  
Article
Modelling of Applied Magnetic Field and Thermal Radiations Due to the Stretching of Cylinder
by Muhammad Tamoor, Muhammad Kamran, Sadique Rehman, Aamir Farooq, Rewayat Khan, Jung Rye Lee and Dong Yun Shin
Processes 2021, 9(6), 1077; https://doi.org/10.3390/pr9061077 - 21 Jun 2021
Cited by 5 | Viewed by 2132
Abstract
In this study, a numerical approach was adopted in order to explore the analysis of magneto fluid in the presence of thermal radiation combined with mixed convective and slip conditions. Using the similarity transformation, the axisymmetric three-dimensional boundary layer equations were reduced to [...] Read more.
In this study, a numerical approach was adopted in order to explore the analysis of magneto fluid in the presence of thermal radiation combined with mixed convective and slip conditions. Using the similarity transformation, the axisymmetric three-dimensional boundary layer equations were reduced to a self-similar form. The shooting technique, combined with the Range–Kutta–Fehlberg method, was used to solve the resulting coupled nonlinear momentum and heat transfer equations numerically. When physically interpreting the data, some important observations were made. The novelty of the present study lies in finding help to control the rate of heat transfer and fluid velocity in any industrial manufacturing processes (such as the cooling of metallic plates). The numerical results revealed that the Nusselt number decrease for larger Prandtl number, curvature, and convective parameters. At the same time, the skin friction coefficient was enhanced with an increase in both slip velocity and convective parameter. The effect of emerging physical parameters on velocity and temperature profiles for a nonlinear stretching cylinder has been thoroughly studied and analyzed using plotted graphs and tables. Full article
(This article belongs to the Special Issue Micro and Nanotechnology: Application in Surface Modification)
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14 pages, 2812 KiB  
Article
Freeze-Drying versus Heat-Drying: Effect on Protein-Based Superabsorbent Material
by Estefanía Álvarez-Castillo, Carlos Bengoechea, Manuel Felix and Antonio Guerrero
Processes 2021, 9(6), 1076; https://doi.org/10.3390/pr9061076 - 21 Jun 2021
Cited by 6 | Viewed by 2835
Abstract
Porcine plasma protein is a by-product of the meat industry, which has already been applied in the manufacture of superabsorbent materials. The effects of plasticizer content (0%, 25%, 50%), together with those of the drying method (freeze-drying, thermal drying at 50 °C), during [...] Read more.
Porcine plasma protein is a by-product of the meat industry, which has already been applied in the manufacture of superabsorbent materials. The effects of plasticizer content (0%, 25%, 50%), together with those of the drying method (freeze-drying, thermal drying at 50 °C), during the processing of superabsorbent porcine plasma matrices were studied in this manuscript. Although the presence of glycerol accelerated the water absorption kinetics, the highest water absorption (~550%) was achieved by samples not containing any plasticizer. Viscoelasticity decreased at higher glycerol contents and especially after water absorption. When swollen samples were dried through freeze-drying, porous structures with a sponge-like appearance were obtained. Oppositely, thermally dried samples suffered an evident shrinkage that reduced porosity, displaying a more uniform surface. The effect of the drying method was observed since only freeze-dried samples can be rehydrated, displaying a superabsorbent ability (absorption higher than 1000%), which could be used in several applications (food, agriculture, personal care). Full article
(This article belongs to the Special Issue Modern Freeze Drying Design for More Efficient Processes)
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17 pages, 1262 KiB  
Review
Guava (Psidium guajava L.) Fruit and Valorization of Industrialization By-Products
by Jorge E. Angulo-López, Adriana C. Flores-Gallegos, Cristian Torres-León, Karen N. Ramírez-Guzmán, Gloria A. Martínez and Cristóbal N. Aguilar
Processes 2021, 9(6), 1075; https://doi.org/10.3390/pr9061075 - 20 Jun 2021
Cited by 38 | Viewed by 19090
Abstract
Guava (Psidium guajava L.), is a fruit considered native to the American tropics. It is of great economic importance in many countries of the world, due to its high production and diversity of products derived from its fruit. It can be consumed [...] Read more.
Guava (Psidium guajava L.), is a fruit considered native to the American tropics. It is of great economic importance in many countries of the world, due to its high production and diversity of products derived from its fruit. It can be consumed fresh or processed. During the fruit’s processing, some residues are generated, such as seeds, rinds, and pulp, which is about 30% of the fresh fruit’s volume. Different studies have shown that it can be used in various industries, such as food, chemical, and pharmaceutical. By-products or processing residues have valuable components. Evidence indicates that it contains significant amounts of dietary fiber (soluble and insoluble), vitamins (A, B, C, β-carotene), essential oils, minerals, proteins (transferrin, ceruloplasmin, albumin), pectins, antioxidants (flavonoids, flavonols, condensed tannins) and volatile organic compounds; these elements can help in the prevention of chronic and degenerative diseases. P. guajava L. is considered a nutraceutical due to its compounds with beneficial properties on health and disease prevention. Therefore, this paper aims to review the physicochemical composition of the different by-products of the processing of guava and its reported uses. Full article
(This article belongs to the Special Issue Use of Agro-Industrial Byproducts and Waste Treatment)
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19 pages, 3995 KiB  
Article
Backstepping Methodology to Troubleshoot Plant-Wide Batch Processes in Data-Rich Industrial Environments
by Federico Zuecco, Matteo Cicciotti, Pierantonio Facco, Fabrizio Bezzo and Massimiliano Barolo
Processes 2021, 9(6), 1074; https://doi.org/10.3390/pr9061074 - 20 Jun 2021
Cited by 1 | Viewed by 2524
Abstract
Troubleshooting batch processes at a plant-wide level requires first finding the unit causing the fault, and then understanding why the fault occurs in that unit. Whereas in the literature case studies discussing the latter issue abound, little attention has been given so far [...] Read more.
Troubleshooting batch processes at a plant-wide level requires first finding the unit causing the fault, and then understanding why the fault occurs in that unit. Whereas in the literature case studies discussing the latter issue abound, little attention has been given so far to the former, which is complex for several reasons: the processing units are often operated in a non-sequential way, with unusual series-parallel arrangements; holding vessels may be required to compensate for lack of production capacity, and reacting phenomena can occur in these vessels; and the evidence of batch abnormality may be available only from the end unit and at the end of the production cycle. We propose a structured methodology to assist the troubleshooting of plant-wide batch processes in data-rich environments where multivariate statistical techniques can be exploited. Namely, we first analyze the last unit wherein the fault manifests itself, and we then step back across the units through the process flow diagram (according to the manufacturing recipe) until the fault cannot be detected by the available field sensors any more. That enables us to isolate the unit wherefrom the fault originates. Interrogation of multivariate statistical models for that unit coupled to engineering judgement allow identifying the most likely root cause of the fault. We apply the proposed methodology to troubleshoot a complex industrial batch process that manufactures a specialty chemical, where productivity was originally limited by unexplained variability of the final product quality. Correction of the fault allowed for a significant increase in productivity. Full article
(This article belongs to the Special Issue Modeling, Control, and Optimization of Batch and Batch-Like Processes)
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10 pages, 802 KiB  
Article
Influence of Physicochemical Properties and Parent Material on Chromium Fractionation in Soils
by Claudia Campillo-Cora, Laura Rodríguez-González, Manuel Arias-Estévez, David Fernández-Calviño and Diego Soto-Gómez
Processes 2021, 9(6), 1073; https://doi.org/10.3390/pr9061073 - 20 Jun 2021
Cited by 6 | Viewed by 1936
Abstract
Chromium is an element that possess several oxidation states and can easily pass from one to another, so its behavior in soils is very complex. For this reason, determining its fate in the environment can be difficult. In this research work we tried [...] Read more.
Chromium is an element that possess several oxidation states and can easily pass from one to another, so its behavior in soils is very complex. For this reason, determining its fate in the environment can be difficult. In this research work we tried to determine which factors affect the chromium fractionation in natural soils, conditioning chromium mobility. We paid special attention to the parent material. For this purpose, extraction experiments were carried out on spiked soils incubated for 50–60 days, using H2O, CaCl2 and diethylenetriaminepentaacetic acid (DTPA). The most efficient extraction rate in all soils was achieved using water, followed by CaCl2 and DTPA. We obtained models with an adjusted R2 of 0.8097, 0.8471 and 0.7509 for the H2O Cr, CaCl2 Cr and DTPA Cr respectively. All models were influenced by the amount of chromium added and the parent material: amphibolite and granite influenced the amount of H2O Cr extracted, and schist affected the other two fractions (CaCl2 and DTPA). Soil texture also played an important role in the chromium extraction, as well as the amounts of exchangeable aluminum and magnesium, and the bioavailable phosphorus. We concluded that it is possible to make relatively accurate predictions of the behavior of the different Cr fractions studied, so that optimized remediation strategies for chromium-contaminated soils can be designed on the basis of a physicochemical soil characterization. Full article
(This article belongs to the Section Environmental and Green Processes)
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22 pages, 3208 KiB  
Article
Modelling and Multi-Objective Optimization of the Sulphur Dioxide Oxidation Process
by Mohammad Reza Zaker, Clémence Fauteux-Lefebvre and Jules Thibault
Processes 2021, 9(6), 1072; https://doi.org/10.3390/pr9061072 - 20 Jun 2021
Cited by 3 | Viewed by 11084
Abstract
Sulphuric acid (H2SO4) is one of the most produced chemicals in the world. The critical step of the sulphuric acid production is the oxidation of sulphur dioxide (SO2) to sulphur trioxide (SO3) which takes place [...] Read more.
Sulphuric acid (H2SO4) is one of the most produced chemicals in the world. The critical step of the sulphuric acid production is the oxidation of sulphur dioxide (SO2) to sulphur trioxide (SO3) which takes place in a multi catalytic bed reactor. In this study, a representative kinetic rate equation was rigorously selected to develop a mathematical model to perform the multi-objective optimization (MOO) of the reactor. The objectives of the MOO were the SO2 conversion, SO3 productivity, and catalyst weight, whereas the decisions variables were the inlet temperature and the length of each catalytic bed. MOO studies were performed for various design scenarios involving a variable number of catalytic beds and different reactor configurations. The MOO process was mainly comprised of two steps: (1) the determination of Pareto domain via the determination a large number of non-dominated solutions, and (2) the ranking of the Pareto-optimal solutions based on preferences of a decision maker. Results show that a reactor comprised of four catalytic beds with an intermediate absorption column provides higher SO2 conversion, marginally superior to four catalytic beds without an intermediate SO3 absorption column. Both scenarios are close to the ideal optimum, where the reactor temperature would be adjusted to always be at the maximum reaction rate. Results clearly highlight the compromise existing between conversion, productivity and catalyst weight. Full article
(This article belongs to the Special Issue Modelling and Optimization of Chemical Reactors)
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14 pages, 4168 KiB  
Article
Anti-Inflammatory Effects of Abeliophyllum distichum Nakai (Cultivar Okhwang 1) Callus through Inhibition of PI3K/Akt, NF-κB, and MAPK Signaling Pathways in Lipopolysaccharide-Induced Macrophages
by Tae-Won Jang and Jae-Ho Park
Processes 2021, 9(6), 1071; https://doi.org/10.3390/pr9061071 - 19 Jun 2021
Cited by 4 | Viewed by 2425
Abstract
One of the Korean endemic plants, Abeliophyllum distichum Nakai (Oleaceae), contains acteoside, which is a glycoside exhibiting neuroprotective, anti-inflammation effects and antibacterial capacities. We conducted an investigation on the effects of the callus of A. distichum (cultivar Okhwang 1, CAO) on pro-inflammatory mediators [...] Read more.
One of the Korean endemic plants, Abeliophyllum distichum Nakai (Oleaceae), contains acteoside, which is a glycoside exhibiting neuroprotective, anti-inflammation effects and antibacterial capacities. We conducted an investigation on the effects of the callus of A. distichum (cultivar Okhwang 1, CAO) on pro-inflammatory mediators released following nuclear factor-кB (NF-кB), phosphatidylinositol 3-kinase/Akt (PI3K-Akt) and mitogen-activated protein kinase (MAPK) signal activation in lipopolysaccharide (LPS)-induced RAW 264.7 cells. Immunoblotting was employed to find out the expression of cyclooxygenase-2 (COX-2), inducible nitric oxide (iNOS), and activation of MAPK molecules, NF-κB and Akt. Cytokines, COX-2, and iNOS gene expression were assessed using polymerase chain reaction techniques. Cytokines, COX-2, and iNOS gene expression were assessed using polymerase chain reaction techniques. High-performance liquid chromatography revealed that CAO was rich in acteoside and isoacteoside. As a result, CAO inhibited the generation of NO, cytokines, COX-2, and iNOS expression. Further, translocation to the nuclear of NF-κB p65 and degradation of the inhibitor of NF-кB (IкB) were alleviated by suppressing phosphorylation. Additionally, CAO significantly impacted MAPK pathway activation by potentially reducing phosphorylation of MAPKs. These results indicate that the anti-inflammatory effect of CAO is mediated via the inhibition of MAPK, PI3K/Akt, and NF-κB signaling pathways, probably via glycosides, phenolics, and flavonoids bioactivity derived from plants. CAO can serve as a potential anti-inflammatory agent, which alleviates inflammation factors and act through specific cell signaling pathways. Full article
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18 pages, 4659 KiB  
Article
Predicting Sooting Propensity of Oxygenated Fuels Using Artificial Neural Networks
by Abdul Gani Abdul Jameel
Processes 2021, 9(6), 1070; https://doi.org/10.3390/pr9061070 - 19 Jun 2021
Cited by 16 | Viewed by 2614
Abstract
The self-learning capabilities of artificial neural networks (ANNs) from large datasets have led to their deployment in the prediction of various physical and chemical phenomena. In the present work, an ANN model was developed to predict the yield sooting index (YSI) [...] Read more.
The self-learning capabilities of artificial neural networks (ANNs) from large datasets have led to their deployment in the prediction of various physical and chemical phenomena. In the present work, an ANN model was developed to predict the yield sooting index (YSI) of oxygenated fuels using the functional group approach. A total of 265 pure compounds comprising six chemical classes, namely paraffins (n and iso), olefins, naphthenes, aromatics, alcohols, and ethers, were dis-assembled into eight constituent functional groups, namely paraffinic CH3 groups, paraffinic CH2 groups, paraffinic CH groups, olefinic –CH=CH2 groups, naphthenic CH-CH2 groups, aromatic C-CH groups, alcoholic OH groups, and ether O groups. These functional groups, in addition to molecular weight and branching index, were used as inputs to develop the ANN model. A neural network with two hidden layers was used to train the model using the Levenberg–Marquardt (ML) training algorithm. The developed model was tested with 15% of the random unseen data points. A regression coefficient (R2) of 0.99 was obtained when the experimental values were compared with the predicted YSI values from the test set. An average error of 3.4% was obtained, which is less than the experimental uncertainty associated with most reported YSI measurements. The developed model can be used for YSI prediction of hydrocarbon fuels containing alcohol and ether-based oxygenates as additives with a high degree of accuracy. Full article
(This article belongs to the Section Energy Systems)
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17 pages, 5438 KiB  
Article
Molecular Dynamics Simulation of Clay Hydration Inhibition of Deep Shale
by Yayun Zhang and Cong Xiao
Processes 2021, 9(6), 1069; https://doi.org/10.3390/pr9061069 - 19 Jun 2021
Cited by 7 | Viewed by 3137
Abstract
In the process of the exploitation of deep oil and gas resources, shale wellbore stability control faces great challenges under complex temperature and pressure conditions. It is difficult to reflect the micro mechanism and process of the action of inorganic salt on shale [...] Read more.
In the process of the exploitation of deep oil and gas resources, shale wellbore stability control faces great challenges under complex temperature and pressure conditions. It is difficult to reflect the micro mechanism and process of the action of inorganic salt on shale hydration with the traditional experimental evaluation technology on the macro effect of restraining shale hydration. Aiming at the characteristics of clay minerals of deep shale, the molecular dynamics models of four typical cations (K+, NH4+, Cs+ and Ca2+) inhibiting the hydration of clay minerals have been established by the use of the molecular dynamics simulation method. Moreover, the micro dynamics mechanism of typical inorganic cations inhibiting the hydration of clay minerals has been systematically evaluated, as has the law of cation hydration inhibition performance in response to temperature, pressure and ion type. The research indicates that the cations can promote the contraction of interlayer spacing, compress fluid intrusion channels, reduce the intrusion ability of water molecules, increase the negative charge balance ability and reduce the interlayer electrostatic repulsion force. With the increase in temperature, the inhibition of the cations on montmorillonite hydration is weakened, while the effect of pressure is opposite. Through the molecular dynamics simulation under different temperatures and pressures, we can systematically understand the microcosmic dynamics mechanism of restraining the hydration of clay in deep shale and provide theoretical guidance for the microcosmic control of clay hydration. Full article
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11 pages, 2563 KiB  
Article
Study on the Removal of Fluorescent Whitening Agent from Paper-Mill Wastewater Using the Submerged Membrane Bioreactor (SMBR) with Ozone Oxidation Process
by Seunghan Ryu, Sanghun Lee, Hannah Oh, Sanghwa Oh, Minsoo Park, Jinho Kim and Jaeeun Heo
Processes 2021, 9(6), 1068; https://doi.org/10.3390/pr9061068 - 18 Jun 2021
Viewed by 2359
Abstract
In this study, paper-mill wastewater was treated using the Submerged Membrane Bioreactor (SMBR) process. In particular, the ozone oxidation treatment process is applied after SMBR to remove the fluorescent whitening agent, which is a trace pollutant and non-biodegradable. Fluorescent whitening agent concentration was [...] Read more.
In this study, paper-mill wastewater was treated using the Submerged Membrane Bioreactor (SMBR) process. In particular, the ozone oxidation treatment process is applied after SMBR to remove the fluorescent whitening agent, which is a trace pollutant and non-biodegradable. Fluorescent whitening agent concentration was indirectly measured by UV scanning and COD concentration. The concentration of COD before SMBR and ozone oxidation was 449.3 mg/L, and the concentration of treated water was 100.3 mg/ℓ. The COD removal efficiency of paper-mill wastewater through SMBR and the ozone oxidation process was about 77.68%. The optimized amount of ozone was required for the removal of the fluorescent whitening agent after SMBR was 95 mg·O3/ℓ calculated by UV scan results. Additionally, the optimized amount of required ozone to remove COD was calculated to 0.126 mg·COD/mg·O3. Full article
(This article belongs to the Special Issue Advances in Water and Wastewater Treatment Processes)
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18 pages, 2981 KiB  
Article
Magnetic Particle Inspection Optimization Solution within the Frame of NDT 4.0
by Andreea Ioana Sacarea, Gheorghe Oancea and Luminita Parv
Processes 2021, 9(6), 1067; https://doi.org/10.3390/pr9061067 - 18 Jun 2021
Cited by 11 | Viewed by 3839
Abstract
The quality of product and process is one of the most important factors in achieving constructively and then functionally safe products in any industry. Over the years, the concept of Industry 4.0 has emerged in all the quality processes, such as nondestructive testing [...] Read more.
The quality of product and process is one of the most important factors in achieving constructively and then functionally safe products in any industry. Over the years, the concept of Industry 4.0 has emerged in all the quality processes, such as nondestructive testing (NDT). The most widely used quality control methods in the industries of mechanical engineering, aerospace, and civil engineering are nondestructive methods, which are based on inspection by detecting indications, without affecting the surface quality of the examined parts. Over time, the focus has been on research with the fourth generation in nondestructive testing, i.e., NDT 4.0 or Smart NDT, as a main topic to ensure the efficiency and effectiveness of the methods for a safe detection of all types of discontinuities. This area of research aims at the efficiency of methods, the elimination of human errors, digitalization, and optimization from a constructive point of view. In this paper, we presented a magnetic particles inspection method and the possible future directions for the development of standard equipment used in the context of this method in accordance with the applicable physical principles and constraints of the method for cylindrical parts. A possible development direction was presented in order to streamline the mass production of parts made of ferromagnetic materials. We described the methods of analysis and the tools used for the development of a magnetic particle inspection method used for cylindrical parts in all types of industry and NDT 4.0; the aim is to provide new NDT 4.0 directions in optimizing the series production for cylindrical parts from industry, as given in the conclusion of this article. Full article
(This article belongs to the Special Issue Process Control and Smart Manufacturing for Industry 4.0)
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9 pages, 2895 KiB  
Article
Group Acceptance Sampling Plan Using Marshall–Olkin Kumaraswamy Exponential (MOKw-E) Distribution
by Abdullah M. Almarashi, Khushnoor Khan, Christophe Chesneau and Farrukh Jamal
Processes 2021, 9(6), 1066; https://doi.org/10.3390/pr9061066 - 18 Jun 2021
Cited by 21 | Viewed by 2342
Abstract
The current research concerns the group acceptance sampling plan in the case where (i) the lifetime of the items follows the Marshall–Olkin Kumaraswamy exponential distribution (MOKw-E) and (ii) a large number of items, considered as a group, can be tested at [...] Read more.
The current research concerns the group acceptance sampling plan in the case where (i) the lifetime of the items follows the Marshall–Olkin Kumaraswamy exponential distribution (MOKw-E) and (ii) a large number of items, considered as a group, can be tested at the same time. When the consumer’s risk and the test terminsation period are defined, the key design parameters are extracted. The values of the operating characteristic function are determined for different quality levels. At the specified producer’s risk, the minimum ratios of the true average life to the specified average life are also calculated. The results of the present study will set the platform for future research on various nano quality level topics when the items follow different probability distributions under the Marshall–Olkin Kumaraswamy scheme. Real-world data are used to explain the technique. Full article
(This article belongs to the Special Issue Neural Networks, Fuzzy Systems and Other Computational Intelligence Techniques for Advanced Process Control)
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24 pages, 1732 KiB  
Article
Influence of Orchard Cultural Practices during the Productive Process of Cherries through Life Cycle Assessment
by Pedro Dinis Gaspar, Radu Godina and Rui Barrau
Processes 2021, 9(6), 1065; https://doi.org/10.3390/pr9061065 - 18 Jun 2021
Cited by 5 | Viewed by 2530
Abstract
This study describes the influence of orchard cultural practices during the productive process of cherries on the environmental impact in terms of energy, air, soil and water through a “farm to market” Life Cycle Assessment (LCA). The results were used to identify the [...] Read more.
This study describes the influence of orchard cultural practices during the productive process of cherries on the environmental impact in terms of energy, air, soil and water through a “farm to market” Life Cycle Assessment (LCA). The results were used to identify the orchard cultural practices that contribute significantly to the environmental impact and to find solutions to reduce those impacts, serving as best practices guide to improving the environmental performance and as benchmarks for other national and international cherry and fruit growers. Primary data for production, harvest and post-harvest periods were gathered experimentally. The openLCA 1.10.2 software and the ecoinvent 3.5 database were used for modelling. Test case scenarios are modelled to identify the influence of cultural practices in low and high cherry production campaigns depending on climatic conditions and consequently diseases and plagues. Moreover, results are compared with other studies, not only covering cherries but also other fruits. The energy consumption per hectare in the production phase is similar in test scenarios. The energy consumption of orchard cultural practices related to tractor use, fertilizers and fungicides application are the main hotspots in terms of global warming, freshwater ecotoxicity and eutrophication, and terrestrial acidification. The use of electric vehicles, change the warehouse location or redefine transportation routes can reduce this impact, along with the optimization of the cherry’s quantity transported in each trip. In addition, the use of plant protection products, fertilizers and herbicides with less environmental impact will contribute to this objective. For that, the use of agriculture and precision systems to predict the need for fertilizers (nutrients), herbicides and fungicides, the use of decision support systems to define the dates of cultural practices, as well as innovative and emerging food and by-products processing methods are suggested. Thus, this study identifies and quantifies the environmental impacts associated with the production system of cherries and their main hotspots. It provides a best-practices guide for sustainable solutions in orchard management that contributes to the competitiveness and sustainability of fruit companies. Full article
(This article belongs to the Special Issue Biotechnological Food-Oriented Processes)
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14 pages, 690 KiB  
Article
Olive Oil Dregs as a Novel Source of Natural Antioxidants: Extraction Optimization towards a Sustainable Process
by Giuseppe Squillaci, Alice Marchetti, Orsolina Petillo, Michela Bosetti, Francesco La Cara, Gianfranco Peluso and Alessandra Morana
Processes 2021, 9(6), 1064; https://doi.org/10.3390/pr9061064 - 18 Jun 2021
Cited by 3 | Viewed by 2595
Abstract
Olive oil dregs (OOD), which are an underutilized by-product from oil mills, were used for the extraction of antioxidant compounds. The residues from three oil mills located in Campania (Southern Italy) were extracted with acidified methanol, and hydroxytyrosol (HT) was the main phenolic [...] Read more.
Olive oil dregs (OOD), which are an underutilized by-product from oil mills, were used for the extraction of antioxidant compounds. The residues from three oil mills located in Campania (Southern Italy) were extracted with acidified methanol, and hydroxytyrosol (HT) was the main phenolic compound detected. Total phenolic content (TPC) and HT amount were measured. EVO Campania oil mill provided the residue with the highest TPC and HT quantities: 6.801 ± 0.159 mg Gallic Acid Equivalents (GAE)/g OOD and 519.865 ± 9.082 μg/g OOD, respectively. Eco-friendly extractions at different temperatures and times were performed on EVO Campania OOD, obtaining 9.122 ± 0.104 mg GAE/g OOD and 541.330 ± 64.087 μg/g OOD for TPC and HT, respectively, at 121 °C for 60 min. Radical Scavenging Activity (RSA), Superoxide Scavenging Activity (SSA), and Ferric Reducing Antioxidant Power (FRAP) were measured in OOD aqueous extracts. Extract prepared at 37 °C for 60 min showed the greatest RSA and SSA values (44.12 ± 1.82 and 75.72 ± 1.78, respectively), whereas extract prepared at 121 °C for 60 min exhibited the highest FRAP value (129.10 ± 10.49 μg Ascorbic Acid Equivalents (AAE)/mg). OOD extracts were able to protect sunflower oil from oxidation for 4 weeks at 65 °C. The overall results suggest that this novel residue can be usefully valorized by providing HT-rich extracts to use as antioxidant agents. Full article
(This article belongs to the Special Issue Extraction Optimization Processes of Antioxidants)
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8 pages, 2667 KiB  
Article
A Computational Approach for Pathway-Based Systemic Drug Influence
by Shinuk Kim
Processes 2021, 9(6), 1063; https://doi.org/10.3390/pr9061063 - 17 Jun 2021
Cited by 2 | Viewed by 1731
Abstract
Drug repositioning is a well-known method used to reduce the time, cost, and development risks involved in bringing a new drug to the market. The rapid expansion of high-throughput datasets has enabled computational research that can suggest new potential uses for existing drugs. [...] Read more.
Drug repositioning is a well-known method used to reduce the time, cost, and development risks involved in bringing a new drug to the market. The rapid expansion of high-throughput datasets has enabled computational research that can suggest new potential uses for existing drugs. Some computational methods allow the prediction of potential drug targets of a given disease from a systematic network. Despite numerous efforts, the path of many drugs’ efficacy in the human body remains unclear. Therefore, the present study attempted to understand drug efficacy by systematically focusing on functional gene sets. The purpose of this study was to carry out modeling to identify systemic gene networks (called drug paths) in drug-specific pathways. In our results, we found five different paths for five different drugs. Full article
(This article belongs to the Section Biological Processes and Systems)
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15 pages, 2647 KiB  
Article
Advanced Methods for Kiln-Shell Monitoring to Optimize the Waelz Process for Zinc Recycling
by Markus Vogelbacher, Sina Keller, Wolfgang Zehm and Jörg Matthes
Processes 2021, 9(6), 1062; https://doi.org/10.3390/pr9061062 - 17 Jun 2021
Cited by 8 | Viewed by 2674
Abstract
The recycling of zinc in the Waelz process is an important part of the efficient use of resources in the steel processing cycle. The pyro-metallurgical processing of zinc-containing wastes takes place in a Waelz rotary kiln. Various measured variables are available to monitor [...] Read more.
The recycling of zinc in the Waelz process is an important part of the efficient use of resources in the steel processing cycle. The pyro-metallurgical processing of zinc-containing wastes takes place in a Waelz rotary kiln. Various measured variables are available to monitor the process. The temperature of the kiln-shell is analyzed by an infrared kiln-shell-scanner. In this paper, methods are presented which eliminate external weather-related disturbances on the temperature measured by the kiln-shell-scanner using a weather model and which extend the monitoring of the regularly necessary melting process to remove accretions. For this purpose, an adapted sigmoid estimation is introduced for the melting process, which provides new information about the current process status and a forecast of the further development of the melting process. As an assistance system for the plant operator, this enables an efficient execution of the melting process and reduces downtimes. Full article
(This article belongs to the Section Process Control and Monitoring)
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16 pages, 2021 KiB  
Article
Improving Retail Warehouse Activity by Using Product Delivery Data
by Aurelija Burinskienė and Tone Lerher
Processes 2021, 9(6), 1061; https://doi.org/10.3390/pr9061061 - 17 Jun 2021
Cited by 2 | Viewed by 3833
Abstract
This paper presents a research study which is dedicated to the improvement in retail warehouse activity. This study aims to improve activity by identifying an efficient order picking strategy. (1) Background: The literature review shows the application of order picking strategies, but research [...] Read more.
This paper presents a research study which is dedicated to the improvement in retail warehouse activity. This study aims to improve activity by identifying an efficient order picking strategy. (1) Background: The literature review shows the application of order picking strategies, but research related to their selection lacks an integrated approach. (2) Methods: The authors use the discrete event simulation method for the analysis of order picking strategies. The application of the discrete event simulation method enables various scenario tests in retail warehouses, allowing one to benchmark order picking strategies. By using the simulation model, experiments were designed to evaluate order picking strategies that are dependent on the delivery of the product distance variable. This research uses analysis of cost components and helps to identify the best possible order picking strategy to improve the overall warehouse performance. The authors benchmarked order picking strategies and presented constraints following product delivery data concerning their applications. (3) Results: The results presented show that the application of the order sorting strategy delivers 46.6% and the order batching strategy 6.7% lower costs compared to the single picking strategy. The results of the order batching strategy could be improved by 8.34% when the product clustering action is used. (4) Conclusions: The authors provide a theoretical framework which follows the application of order picking strategies using the product delivery data approach, which is the main scientific novelty of this paper. Recommendations are provided regarding the application of the proposed framework for the future improvement in retail warehouse activity. Full article
(This article belongs to the Special Issue Modeling, Simulation and Control of Flexible Manufacturing Systems)
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16 pages, 5699 KiB  
Article
Spiral Vibration Cooler for Continual Cooling of Biomass Pellets
by David Žurovec, Lucie Jezerská, Jan Nečas, Jakub Hlosta, Jan Diviš and Jiří Zegzulka
Processes 2021, 9(6), 1060; https://doi.org/10.3390/pr9061060 - 17 Jun 2021
Cited by 2 | Viewed by 2938
Abstract
Cooling is an important process during the production of pellets (as post-treatment). The pellet cooling process significantly impacts the quality of the pellets produced and the systematic use of energy. However, the cooling systems currently in use sometimes encounter technical problems, such as [...] Read more.
Cooling is an important process during the production of pellets (as post-treatment). The pellet cooling process significantly impacts the quality of the pellets produced and the systematic use of energy. However, the cooling systems currently in use sometimes encounter technical problems, such as clogging of the perforated grids (sieves), the discharge hopper, or pellet degradation may occur. Therefore, a prototype of a new pellet cooling system using a vibrating feeder was tested. The aim of the study is to present a new variation of pellet cooling system using spiral vibration cooler as a possible solution next to a counterflow cooler. The presented system was tested (critically evaluated and discussed) in two design variants. The first variant consists in cooling by chaotic movement of the pellets. The second is then in combination with the chaotic movement of the pellets together with the action of intense air flow using specially placed air hoses. All tests involved pelletization of rapeseed straw. It was found that both cooling system variants could, realistically, be used. However, the variant with an intense air flow was more energy-intensive, a factor which is, however, offset by the higher quality of the pellets. No negative impact of vibrations to pellets quality was occur. Studies provide insight into new usable technologies that do not reduce the efficiency of the process as a result of grate clogging. Full article
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19 pages, 3980 KiB  
Article
Fundamental Understanding of Tea Growth and Modeling of Precise Tea Shoot Picking Based on 3-D Coordinate Instrument
by Xiaoming Wang, Chongyang Han, Weibin Wu, Jian Xu, Qingzhao Zhang, Ming Chen, Zhibiao Hu and Zefeng Zheng
Processes 2021, 9(6), 1059; https://doi.org/10.3390/pr9061059 - 17 Jun 2021
Cited by 8 | Viewed by 3107
Abstract
Tea is a popular beverage worldwide and also has great medical value. A fundamental understanding of tea shoot growth and a precision picking model should be established to realize mechanized picking of tea shoots with a small product loss. Accordingly, the terminal bud [...] Read more.
Tea is a popular beverage worldwide and also has great medical value. A fundamental understanding of tea shoot growth and a precision picking model should be established to realize mechanized picking of tea shoots with a small product loss. Accordingly, the terminal bud length (Lbud), tea stem length (Lstem), terminal bud angle (αbud), tea stem angle (αstem), and growth time (t) were considered as the key growth parameters; the sum of the vertical lengths of the terminal bud and stem (ξ), the picking radius (r), and the vertical length of the stem (Zstem) were considered as the picking indexes of the tea shoots. The variations in growth parameters with time were investigated using a 3-D coordinate instrument, and the relationships between the growth parameters and the picking indexes were established using an artificial neural network (ANN). The results indicated that the tea growth cycles for periods P1, P2, P3, P4, P5, and P6 were 14, 7, 6, 4, 4, and 6 d, respectively. A growth cycle diagram of the tea growth was established. Moreover, a 5-2-12-3 ANN model was developed. The best prediction of ξ, r, and Zstem was found with 16 training epochs. The MSE value was 0.0923 × 10−4, and the R values for the training, test, and validation data were 0.99976, 0.99871, and 0.99857, respectively, indicating that the established ANN model demonstrates excellent performance in predicting the picking indexes of tea shoots. Full article
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27 pages, 88783 KiB  
Article
Pool Boiling Performance of Water and Self-Rewetting Fluids on Hybrid Functionalized Aluminum Surfaces
by Matic Može, Viktor Vajc, Matevž Zupančič, Radek Šulc and Iztok Golobič
Processes 2021, 9(6), 1058; https://doi.org/10.3390/pr9061058 - 17 Jun 2021
Cited by 20 | Viewed by 3948
Abstract
The boiling performance of functionalized hybrid aluminum surfaces was experimentally investigated for water and self-rewetting mixtures of water and 1-butanol. Firstly, microstructured surfaces were produced via chemical etching in hydrochloric acid and the effect of the etching time on the surface morphology was [...] Read more.
The boiling performance of functionalized hybrid aluminum surfaces was experimentally investigated for water and self-rewetting mixtures of water and 1-butanol. Firstly, microstructured surfaces were produced via chemical etching in hydrochloric acid and the effect of the etching time on the surface morphology was evaluated. An etching time of 5 min was found to result in pitting corrosion and produced weakly hydrophilic microstructured surfaces with many microcavities. Observed cavity-mouth diameters between 3.6 and 32 μm are optimal for efficient nucleation and provided a superior boiling performance. Longer etching times of 10 and 15 min resulted in uniform corrosion and produced superhydrophilic surfaces with a micropeak structure, which lacked microcavities for efficient nucleation. In the second stage, hybrid surfaces combining lower surface energy and a modified surface microstructure were created by hydrophobization of etched aluminum surfaces using a silane agent. Hydrophobized surfaces were found to improve boiling heat transfer and their boiling curves exhibited a significantly lower superheat. Significant heat transfer enhancement was observed for hybrid microcavity surfaces with a low surface energy. These surfaces provided an early transition into nucleate boiling and promoted bubble nucleation. For a hydrophobized microcavity surface, heat transfer coefficients of up to 305 kW m−2 K−1 were recorded and an enhancement of 488% relative to the untreated reference surface was observed. The boiling of self-rewetting fluids on functionalized surfaces was also investigated, but a synergistic effect of developed surfaces and a self-rewetting working fluid was not observed. An improved critical heat flux was only obtained for the untreated surface, while a lower critical heat flux and lower heat transfer coefficients were measured on functionalized surfaces, whose properties were already tailored to promote nucleate boiling. Full article
(This article belongs to the Special Issue Two-Phase Flow Heat Transfer: Design, Simulation and Optimization)
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14 pages, 1264 KiB  
Review
Drug Repurposing Using Biological Networks
by Francisco Javier Somolinos, Carlos León and Sara Guerrero-Aspizua
Processes 2021, 9(6), 1057; https://doi.org/10.3390/pr9061057 - 17 Jun 2021
Cited by 20 | Viewed by 4896
Abstract
Drug repositioning is a strategy to identify new uses for existing, approved, or research drugs that are outside the scope of its original medical indication. Drug repurposing is based on the fact that one drug can act on multiple targets or that two [...] Read more.
Drug repositioning is a strategy to identify new uses for existing, approved, or research drugs that are outside the scope of its original medical indication. Drug repurposing is based on the fact that one drug can act on multiple targets or that two diseases can have molecular similarities, among others. Currently, thanks to the rapid advancement of high-performance technologies, a massive amount of biological and biomedical data is being generated. This allows the use of computational methods and models based on biological networks to develop new possibilities for drug repurposing. Therefore, here, we provide an in-depth review of the main applications of drug repositioning that have been carried out using biological network models. The goal of this review is to show the usefulness of these computational methods to predict associations and to find candidate drugs for repositioning in new indications of certain diseases. Full article
(This article belongs to the Section Biological Processes and Systems)
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9 pages, 294 KiB  
Communication
Hydrogen Gas Quality for Gas Network Injection: State of the Art of Three Hydrogen Production Methods
by Oluwafemi Omoniyi, Thomas Bacquart, Niamh Moore, Sam Bartlett, Katie Williams, Sharon Goddard, Bob Lipscombe, Arul Murugan and David Jones
Processes 2021, 9(6), 1056; https://doi.org/10.3390/pr9061056 - 17 Jun 2021
Cited by 13 | Viewed by 4529
Abstract
The widescale distribution of hydrogen through gas networks is promoted as a viable and cost-efficient option for optimising its application in heat, industry, and transport. It is a key step towards achieving decarbonisation targets in the UK. A key consideration before the injection [...] Read more.
The widescale distribution of hydrogen through gas networks is promoted as a viable and cost-efficient option for optimising its application in heat, industry, and transport. It is a key step towards achieving decarbonisation targets in the UK. A key consideration before the injection of hydrogen into the UK gas networks is an assessment of the difference in hydrogen contaminants presence from different production methods. This information is essential for gas regulation and for further purification requirements. This study investigates the level of ISO 14687 Grade D contaminants in hydrogen from steam methane reforming, proton exchange membrane water electrolysis, and alkaline electrolysis. Sampling and analysis of hydrogen were carried out by the National Physical Laboratory following ISO 21087 guidance. The results of analysis indicated the presence of nitrogen in hydrogen from electrolysis, and water, carbon dioxide, and particles in all samples analysed. The contaminants were at levels below or at the threshold limits set by ISO 14687 Grade D. This indicates that the investigated production methods are not a source of contaminants for the eventual utilisation of hydrogen in different applications including fuel cell electric vehicles (FCEV’s). The gas network infrastructure will require a similar analysis to determine the likelihood of contamination to hydrogen gas. Full article
(This article belongs to the Section Energy Systems)
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15 pages, 4024 KiB  
Article
g-C3N4 Sensitized by an Indoline Dye for Photocatalytic H2 Evolution
by Yihang Chen, Yanfei Liu and Zhen Ma
Processes 2021, 9(6), 1055; https://doi.org/10.3390/pr9061055 - 17 Jun 2021
Cited by 5 | Viewed by 2294
Abstract
Protonated g-C3N4 (pCN) formed by treating bulk g-C3N4 with an aqueous HCl solution was modified with D149 dye, i.e., 5-[[4[4-(2,2-diphenylethenyl) phenyl]-1,2,3,3a,4,8b-hexahydrocyclopent[b]indol-7-yl] methylene]-2-(3-ethyl-4-oxo-2-thioxo-5-thiazolidinylidene)-4-oxo-thiazolidin-2-ylidenerhodanine, for photocatalytic water splitting (using Pt as a co-catalyst). The D149/pCN-Pt composite showed a much [...] Read more.
Protonated g-C3N4 (pCN) formed by treating bulk g-C3N4 with an aqueous HCl solution was modified with D149 dye, i.e., 5-[[4[4-(2,2-diphenylethenyl) phenyl]-1,2,3,3a,4,8b-hexahydrocyclopent[b]indol-7-yl] methylene]-2-(3-ethyl-4-oxo-2-thioxo-5-thiazolidinylidene)-4-oxo-thiazolidin-2-ylidenerhodanine, for photocatalytic water splitting (using Pt as a co-catalyst). The D149/pCN-Pt composite showed a much higher rate (2138.2 µmol·h−1·g−1) of H2 production than pCN-Pt (657.0 µmol·h−1·g−1). Through relevant characterization, the significantly high activity of D149/pCN-Pt was linked to improved absorption of visible light, accelerated electron transfer, and more efficient separation of charge carriers. The presence of both D149 and Pt was found to be important for these factors. A mechanism was proposed. Full article
(This article belongs to the Special Issue Redesign Processes in the Age of the Fourth Industrial Revolution)
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3 pages, 190 KiB  
Editorial
Special Issue on “Thermal Safety of Chemical Processes”
by Dimitri Lefebvre and Sébastien Leveneur
Processes 2021, 9(6), 1054; https://doi.org/10.3390/pr9061054 - 17 Jun 2021
Cited by 2 | Viewed by 1723
Abstract
Chemistry plays an essential role in our modern society [...] Full article
(This article belongs to the Special Issue Thermal Safety of Chemical Processes)
16 pages, 1022 KiB  
Article
Introducing Parameter Clustering to the OED Procedure for Model Calibration of a Synthetic Inducible Promoter in S. cerevisiae
by Zhaozheng Hou
Processes 2021, 9(6), 1053; https://doi.org/10.3390/pr9061053 - 16 Jun 2021
Viewed by 1982
Abstract
In recent years, synthetic gene circuits for adding new cell features have become one of the most powerful tools in biological and pharmaceutical research and development. However, because of the inherent non-linearity and noisy experimental data, the experiment-based model calibration of these synthetic [...] Read more.
In recent years, synthetic gene circuits for adding new cell features have become one of the most powerful tools in biological and pharmaceutical research and development. However, because of the inherent non-linearity and noisy experimental data, the experiment-based model calibration of these synthetic parts is perceived as a laborious and time-consuming procedure. Although the optimal experimental design (OED) based on the Fisher information matrix (FIM) has been proved to be an effective means to improve the calibration efficiency, the required calculation increases dramatically with the model size (parameter number). To reduce the OED complexity without losing the calibration accuracy, this paper proposes two OED approaches with different parameter clustering methods and validates the accuracy of calibrated models with in-silico experiments. A model of an inducible synthetic promoter in S. cerevisiae is adopted for bench-marking. The comparison with the traditional off-line OED approach suggests that the OED approaches with both of the clustering methods significantly reduce the complexity of OED problems (for at least 49.0%), while slightly improving the calibration accuracy (11.8% and 19.6% lower estimation error in average for FIM-based and sensitivity-based approaches). This study implicates that for calibrating non-linear models of biological pathways, cluster-based OED could be a beneficial approach to improve the efficiency of optimal experimental design. Full article
(This article belongs to the Section Process Control and Monitoring)
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15 pages, 8827 KiB  
Article
Control of Sunroof Buffeting Noise by Optimizing the Flow Field Characteristics of a Commercial Vehicle
by Rongjiang Tang, Hongbin He, Zengjun Lu, Shenfang Li, Enyong Xu, Fei Xiao and Avelino Núñez-Delgado
Processes 2021, 9(6), 1052; https://doi.org/10.3390/pr9061052 - 16 Jun 2021
Cited by 3 | Viewed by 3103
Abstract
When a commercial vehicle is driving with the sunroof open, it is easy for the problem of sunroof buffeting noise to occur. This paper establishes the basis for the design of a commercial vehicle model that solves the problem of sunroof buffeting noise, [...] Read more.
When a commercial vehicle is driving with the sunroof open, it is easy for the problem of sunroof buffeting noise to occur. This paper establishes the basis for the design of a commercial vehicle model that solves the problem of sunroof buffeting noise, which is based on computational fluid dynamics (CFD) numerical simulation technology. The large eddy simulation (LES) method was used to analyze the characteristics of the buffeting noise with different speed conditions while the sunroof was open. The simulation results showed that the small vortex generated in the cab forehead merges into a large vortex during the backward movement, and the turbulent vortex causes a resonance response in the cab cavity as the turbulent vortex moves above the sunroof and falls into the cab. Improving the flow field characteristics above the cab can reduce the sunroof buffeting noise. Focusing on the buffeting noise of commercial vehicles, it is proposed that the existing accessories, including sun visors and roof domes, are optimized to deal with the problem of sunroof buffeting noise. The sound pressure level of the sunroof buffeting noise was reduced by 6.7 dB after optimization. At the same time, the local pressure drag of the commercial vehicle was reduced, and the wind resistance coefficient was reduced by 1.55% compared to the original commercial vehicle. These results can be considered as relevant, with high potential applicability, within this field of research. Full article
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16 pages, 20577 KiB  
Article
A Theoretical Study on the Thermodynamic Cycle of Concept Engine with Miller Cycle
by Jungmo Oh, Kichol Noh and Changhee Lee
Processes 2021, 9(6), 1051; https://doi.org/10.3390/pr9061051 - 16 Jun 2021
Cited by 9 | Viewed by 5421
Abstract
The Atkinson cycle, where expansion ratio is higher than the compression ratio, is one of the methods used to improve thermal efficiency of engines. Miller improved the Atkinson cycle by controlling the intake- or exhaust-valve closing timing, a technique which is called the [...] Read more.
The Atkinson cycle, where expansion ratio is higher than the compression ratio, is one of the methods used to improve thermal efficiency of engines. Miller improved the Atkinson cycle by controlling the intake- or exhaust-valve closing timing, a technique which is called the Miller cycle. The Otto–Miller cycle can improve thermal efficiency and reduce NOx emission by reducing compression work; however, it must compensate for the compression pressure and maintain the intake air mass through an effective compression ratio or turbocharge. Hence, we performed thermodynamic cycle analysis with changes in the intake-valve closing timing for the Otto–Miller cycle and evaluated the engine performance and Miller timing through the resulting problems and solutions. When only the compression ratio was compensated, the theoretical thermal efficiency of the Otto–Miller cycle improved by approximately 18.8% compared to that of the Otto cycle. In terms of thermal efficiency, it is more advantageous to compensate only the compression ratio; however, when considering the output of the engine, it is advantageous to also compensate the boost pressure to maintain the intake air mass flow rate. Full article
(This article belongs to the Special Issue Advanced Combustion and Combustion Diagnostic Techniques)
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