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Processes, Volume 8, Issue 8 (August 2020) – 126 articles

Cover Story (view full-size image): The hydrogenation of trans,trans-muconic acid (ttMA) was investigated on a 5%Pt/C with the purpose of developing a kinetic model able to predict conversions and product distributions. A dual-site Langmuir–Hinshelwood–Hougen–Watson model with hydrogen dissociation provided good fitting. The model parameters were regressed by robust numerical methods and different reaction mechanisms were tested: the best model involves two subsequent hydrogenation steps. The first step converts MA to a monounsaturated intermediate, which is further hydrogenated to adipic acid. The activation energy values and the rate constants were calculated for the reactions, providing the first references for ttMA hydrogenation. View this paper.
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28 pages, 8498 KiB  
Review
Optimization of Magnetic Properties of Magnetic Microwires by Post-Processing
by Valentina Zhukova, Paula Corte-Leon, Lorena González-Legarreta, Ahmed Talaat, Juan Maria Blanco, Mihail Ipatov, Jesus Olivera and Arcady Zhukov
Processes 2020, 8(8), 1006; https://doi.org/10.3390/pr8081006 - 18 Aug 2020
Cited by 14 | Viewed by 3633
Abstract
The influence of post-processing conditions on the magnetic properties of amorphous and nanocrystalline microwires has been thoroughly analyzed, paying attention to the influence of magnetoelastic, induced and magnetocrystalline anisotropies on the hysteresis loops of Fe-, Ni-, and Co-rich microwires. We showed that magnetic [...] Read more.
The influence of post-processing conditions on the magnetic properties of amorphous and nanocrystalline microwires has been thoroughly analyzed, paying attention to the influence of magnetoelastic, induced and magnetocrystalline anisotropies on the hysteresis loops of Fe-, Ni-, and Co-rich microwires. We showed that magnetic properties of glass-coated microwires can be tuned by the selection of appropriate chemical composition and geometry in as-prepared state or further considerably modified by appropriate post-processing, which consists of either annealing or glass-coated removal. Furthermore, stress-annealing or Joule heating can further effectively modify the magnetic properties of amorphous magnetic microwires owing to induced magnetic anisotropy. Devitrification of microwires can be useful for either magnetic softening or magnetic hardening of the microwires. Depending on the chemical composition of the metallic nucleus and on structural features (grain size, precipitating phases), nanocrystalline microwires can exhibit either soft magnetic properties or semi-hard magnetic properties. We demonstrated that the microwires with coercivities from 1 A/m to 40 kA/m can be prepared. Full article
(This article belongs to the Special Issue Advances in Innovative Engineering Materials and Processes)
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4 pages, 460 KiB  
Editorial
Processes for Bioenergy and Resources Recovery from Biowaste
by Elsayed Elbeshbishy and Bipro Ranjan Dhar
Processes 2020, 8(8), 1005; https://doi.org/10.3390/pr8081005 - 18 Aug 2020
Cited by 2 | Viewed by 2311
Abstract
The increasing quantity of biowaste generation and the requirements governing their ultimate disposal are of serious economic and environmental concern [...] Full article
(This article belongs to the Special Issue Processes for Bioenergy and Resources Recovery from Biowaste)
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37 pages, 1766 KiB  
Review
Methods Used for the Compaction and Molding of Ceramic Matrix Composites Reinforced with Carbon Nanotubes
by Valerii P. Meshalkin and Alexey V. Belyakov
Processes 2020, 8(8), 1004; https://doi.org/10.3390/pr8081004 - 18 Aug 2020
Cited by 26 | Viewed by 8273
Abstract
Ceramic matrix composites reinforced with carbon nanotubes are becoming increasingly popular in industry due to their astonishing mechanical properties and taking into account the fact that advanced production technologies make carbon nanotubes increasingly affordable. In the present paper, the most convenient contemporary methods [...] Read more.
Ceramic matrix composites reinforced with carbon nanotubes are becoming increasingly popular in industry due to their astonishing mechanical properties and taking into account the fact that advanced production technologies make carbon nanotubes increasingly affordable. In the present paper, the most convenient contemporary methods used for the compaction of molding masses composed of either technical ceramics or ceramic matrix composites reinforced with carbon nanotubes are surveyed. This stage that precedes debinding and sintering plays the key role in getting pore-free equal-density ceramics at the scale of mass production. The methods include: compaction in sealed and collector molds, cold isostatic and quasi-isostatic compaction; dynamic compaction methods, such as magnetic pulse, vibration, and ultrasonic compaction; extrusion, stamping, and injection; casting from aqueous and non-aqueous slips; tape and gel casting. Capabilities of mold-free approaches to produce precisely shaped ceramic bodies are also critically analyzed, including green ceramic machining and additive manufacturing technologies. Full article
(This article belongs to the Special Issue Advances in Innovative Engineering Materials and Processes)
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16 pages, 8763 KiB  
Article
Eucalyptus camaldulensis, Citrus aurantium, and Citrus sinensis Essential Oils as Antifungal Activity against Aspergillus flavus, Aspergillus niger, Aspergillus terreus, and Fusarium culmorum
by Wael A.A. Abo Elgat, Ahmed M. Kordy, Martin Böhm, Robert Černý, Ahmed Abdel-Megeed and Mohamed Z.M. Salem
Processes 2020, 8(8), 1003; https://doi.org/10.3390/pr8081003 - 18 Aug 2020
Cited by 34 | Viewed by 7886
Abstract
Several molds are able to colonize wood and many building products or solid wood causing losses for their valuable uses. Essential oils (EOs) from aromatic plants can be used as an ecofriendly biofungicide against the growth of several molds. EOs from Eucalyptus camaldulensis [...] Read more.
Several molds are able to colonize wood and many building products or solid wood causing losses for their valuable uses. Essential oils (EOs) from aromatic plants can be used as an ecofriendly biofungicide against the growth of several molds. EOs from Eucalyptus camaldulensis, Citrus aurantium, and C. sinensis have a broad-spectrum antimicrobial activity. EOs from of E. camaldulensis air-dried aerial parts, C. aurantium leaf and C. sinensis peel, and their combinations (1:1 v/v) were evaluated for their antifungal activity against the growth of four common mold fungi (Aspergillus flavus, A. niger, A. terreus, and Fusarium culmorum). The chemical compositions of the EOs were analyzed with GC/MS. The main compounds in EO from E. camaldulensis were spathulenol (20.84%), eucalyptol (12.01%), and sabinene (9.73%); in C. aurantium were linalyl acetate (42.29%), and linalool (29.76%); and in C. sinensis were D-limonene (73.4%) and γ-terpinene (22.6%). At 50 µL/mL, C. sinensis EO showed the highest fungal mycilial growth inhibition (FMGI) percentage (86.66%) against A. flavus. C. sinensis, E. camaldulensis, and E. camaldulensis/C. sinensis showed FMGI values of 96%, 91.66%, and 75.66% respectively, against A. niger. EOs from C. aurantium and C. sinensis showed potent activity against A. terreus (100% FMGI), while C. aurantium/E. camaldulensis and E. camaldulensis/C. sinensis showed FMGI values of 74.33% and 70.66%, respectively. Potent activity against F. culmorum with 100% was observed as the application of E. camaldulensis and C. sinensis EOs at 50 µL/mL, while E. camaldulensis/C. sinensis (50 µL/mL) showed FMGI value of 65.66%. The results suggest using the EOs and their combinations from E.camaldulensis, C. aurantium, and C. sinensis as a biofungicide against molds. The potent properties of EOs offer the possibility of using them as eco-friendly, safe, and cost-effective antimicrobials for molds that could cause discoloration of the wood packaging or food spoilage. Full article
(This article belongs to the Special Issue Green Separation and Extraction Processes)
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19 pages, 2347 KiB  
Article
Determination of a Bubble Drag Coefficient during the Formation of Single Gas Bubble in Upward Coflowing Liquid
by Przemysław Luty and Mateusz Prończuk
Processes 2020, 8(8), 999; https://doi.org/10.3390/pr8080999 - 17 Aug 2020
Cited by 9 | Viewed by 3961
Abstract
Bubble flow is present in many processes that are the subject of chemical engineering research. Many correlations for determination of the equivalent bubble diameter can be found in the scientific literature. However, there are only few describing the formation of gas bubbles in [...] Read more.
Bubble flow is present in many processes that are the subject of chemical engineering research. Many correlations for determination of the equivalent bubble diameter can be found in the scientific literature. However, there are only few describing the formation of gas bubbles in flowing liquid. Such a phenomenon occurs for instance in airlift apparatuses. Liquid flowing around the gas bubble creates a hydraulic drag force that leads to reduction of the formed bubble diameter. Usually the value of the hydraulic drag coefficient, cD, for bubble formation in the flowing liquid is assumed to be equal to the drag coefficient for bubbles rising in the stagnant liquid, which is far from the reality. Therefore, in this study, to determine the value of the drag coefficient of bubbles forming in flowing liquid, the diameter of the bubbles formed at different liquid velocity was measured using the shadowgraphy method. Using the balance of forces affecting the bubble formed in the coflowing liquid, the hydraulic drag coefficient was determined. The obtained values of the drag coefficient differed significantly from those calculated using the correlation for gas bubble rising in stagnant liquid. The proposed correlation allowed the determination of the diameter of the gas bubble with satisfactory accuracy. Full article
(This article belongs to the Section Chemical Processes and Systems)
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10 pages, 2688 KiB  
Article
Process Optimization for Green Synthesis of Silver Nanoparticles Using Indonesian Medicinal Plant Extracts
by Kartini Kartini, Amarisa Alviani, Dia Anjarwati, Adinda Finna Fanany, Johan Sukweenadhi and Christina Avanti
Processes 2020, 8(8), 998; https://doi.org/10.3390/pr8080998 - 17 Aug 2020
Cited by 19 | Viewed by 5721
Abstract
Silver nanoparticles (AgNPs) are an interesting metal nanoparticle that can be incorporated into pharmaceutical products, including for diabetic foot ulcers as an antimicrobial agent. Green synthesis of AgNPs using plant extracts has been drawing much attention as it is simple, eco-friendly, stable, and [...] Read more.
Silver nanoparticles (AgNPs) are an interesting metal nanoparticle that can be incorporated into pharmaceutical products, including for diabetic foot ulcers as an antimicrobial agent. Green synthesis of AgNPs using plant extracts has been drawing much attention as it is simple, eco-friendly, stable, and cost-effective. This present study was performed to evaluate the potential of three Indonesian medicinal plant extracts, namely Phyllanthus niruri (PN), Orthosiphon stamineus (OS), and Curcuma longa (CL), as reducing and capping agents in the green synthesis of AgNPs, and to optimize their concentrations. Based on the yields and characteristics of the formed nanoparticles, which were analyzed using a UV-Vis spectrophotometer, particle size analyzer, scanning electron microscope, and X-ray diffractometer, Phyllanthus niruri extract at a concentration of 0.5% was concluded as the best extract in the green synthesis of AgNPs. It is thereby a prospective reducing and capping agent for further scale-up studies. Full article
(This article belongs to the Special Issue Green Separation and Extraction Processes)
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14 pages, 5765 KiB  
Article
Evaluation of the Turbulence Model Influence on the Numerical Simulation of Cavitating Flow with Emphasis on Temperature Effect
by Yilin Deng, Jian Feng, Fulai Wan, Xi Shen and Bin Xu
Processes 2020, 8(8), 997; https://doi.org/10.3390/pr8080997 - 17 Aug 2020
Cited by 4 | Viewed by 2805
Abstract
The aim of this paper is to investigate the influence of different turbulence models (kε, RNG kε, and SST kω) on the numerical simulation of cavitating flow in thermosensitive fluid. The filter-based model [...] Read more.
The aim of this paper is to investigate the influence of different turbulence models (kε, RNG kε, and SST kω) on the numerical simulation of cavitating flow in thermosensitive fluid. The filter-based model and density correction method were employed to correct the turbulent viscosity of the three turbulence models. Numerical results obtained were compared to experimental ones which were conducted on the NACA0015 hydrofoil at different temperatures. The applicability of the numerical solutions of different turbulence model was studied in detail. The modified RNG kε model has higher accuracy in the calculation of cavitating flow at different temperatures. Full article
(This article belongs to the Section Chemical Processes and Systems)
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21 pages, 2155 KiB  
Review
Plasma Agriculture from Laboratory to Farm: A Review
by Pankaj Attri, Kenji Ishikawa, Takamasa Okumura, Kazunori Koga and Masaharu Shiratani
Processes 2020, 8(8), 1002; https://doi.org/10.3390/pr8081002 - 17 Aug 2020
Cited by 142 | Viewed by 14881
Abstract
In recent years, non-thermal plasma (NTP) application in agriculture is rapidly increasing. Many published articles and reviews in the literature are focus on the post-harvest use of plasma in agriculture. However, the pre-harvest application of plasma still in its early stage. Therefore, in [...] Read more.
In recent years, non-thermal plasma (NTP) application in agriculture is rapidly increasing. Many published articles and reviews in the literature are focus on the post-harvest use of plasma in agriculture. However, the pre-harvest application of plasma still in its early stage. Therefore, in this review, we covered the effect of NTP and plasma-treated water (PTW) on seed germination and growth enhancement. Further, we will discuss the change in biochemical analysis, e.g., the variation in phytohormones, phytochemicals, and antioxidant levels of seeds after treatment with NTP and PTW. Lastly, we will address the possibility of using plasma in the actual agriculture field and prospects of this technology. Full article
(This article belongs to the Special Issue Advances in Plasma Diagnostics and Applications)
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14 pages, 2768 KiB  
Article
Efficient Removal of Ni(II) from Aqueous Solution by Date Seeds Powder Biosorbent: Adsorption Kinetics, Isotherm and Thermodynamics
by Abubakr Elkhaleefa, Ismat H. Ali, Eid I. Brima, A. B. Elhag and Babiker Karama
Processes 2020, 8(8), 1001; https://doi.org/10.3390/pr8081001 - 17 Aug 2020
Cited by 18 | Viewed by 3093
Abstract
Adsorption investigations in batch approaches were performed to explore the biosorption of Ni(II) ions from aqueous solutions on date seeds powder. The effects of pH, particle size, initial concentration of Ni(II) ions, adsorbent mass, temperature, and contact on the adsorption efficacy were studied. [...] Read more.
Adsorption investigations in batch approaches were performed to explore the biosorption of Ni(II) ions from aqueous solutions on date seeds powder. The effects of pH, particle size, initial concentration of Ni(II) ions, adsorbent mass, temperature, and contact on the adsorption efficacy were studied. The maximum removal obtained was 90% for an original Ni(II) ion solution concentration of 50 ppm was attained at pH 7 after 30 min and with 0.30 g of an added adsorbent. The four adsorption models, namely Freundlich, Langmuir, Dubinin–Radushkevich (D–R), and Temkin were examined to fit the experimental findings. The adsorption system obeys the Freundlich model. The system was found to follow the pseudo-second order kinetic model. Thermodynamic factors; entropy (ΔS°), enthalpy (ΔH°), and Gibbs free energy (ΔG°) changes were also assessed. Results proved that adsorption of Ni(II) ions is exothermic and spontaneous. Sticking probability value was found to be less than unity, concluding that the process is dominated by physical adsorption. Full article
(This article belongs to the Special Issue Various Adsorbents for Water Purification Processes)
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18 pages, 487 KiB  
Article
Evaluation of Volatile Compounds during Ageing with Oak Chips and Oak Barrel of Muscat Ottonel Wine
by Anamaria Călugăr, Teodora Emilia Coldea, Carmen Rodica Pop, Tiberia Ioana Pop, Anca Cristina Babeș, Claudiu Ioan Bunea, Mihail Manolache and Emese Gal
Processes 2020, 8(8), 1000; https://doi.org/10.3390/pr8081000 - 17 Aug 2020
Cited by 19 | Viewed by 4574
Abstract
The aim of this work was to compare the variations of alcohols compounds in white wine Muscat Ottonel variety aged in the presence of untoasted oak chips, toasted oak chips and untoasted barrel, considering three ageing periods—30, 60, and 90 days. The liquid-liquid [...] Read more.
The aim of this work was to compare the variations of alcohols compounds in white wine Muscat Ottonel variety aged in the presence of untoasted oak chips, toasted oak chips and untoasted barrel, considering three ageing periods—30, 60, and 90 days. The liquid-liquid extraction and gas chromatography coupled to mass spectrometry were used to compare the concentrations of the volatile constituents of Muscat Ottonel wines. A total of 51 volatile compounds were quantified. Alcohols, terpenic and carboxylic acids decreased with ageing time, whereas esters, lactones, and phenolic compounds increased due esterification processes. The chips toast level, method, and duration of ageing, significantly influenced the content of aromatic compounds. Partial least squares regression (PLS-R) clearly discriminated the initial wine and also the wines aged with toasted and untoasted medium. The compounds (alcohols and terpenes) that impart distinctive aroma of Muscat Ottonel were enhanced by untoasted medium. Light toasted oak chips enhanced wood volatile components (acetovanillone and p-vinyl guaiacol). This study provides important scientific results on the ageing of Muscat Ottonel wines with practical economic benefits to winemakers. Alternative less expensive ageing methods and improved control on the wood components extraction process, may contribute to obtaining high-quality wines. Full article
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9 pages, 3300 KiB  
Article
Targeting Collagen Type III in Proteinuric Kidney Disease: Informing Drug Potential Using the Jaccard–Tanimoto Index
by Michelle Liu, Anoushka Dalvi, Sony Dalapati, Natalia Prakash, Zhijian Hu, Ping Zhou, Kai Jiang, Anthony Pellicano, Itzhak D. Goldberg and Prakash Narayan
Processes 2020, 8(8), 996; https://doi.org/10.3390/pr8080996 - 16 Aug 2020
Cited by 1 | Viewed by 3696
Abstract
Collagenofibrotic glomerulopathy, a collagen type III kidney disease, is associated with proteinuria and accumulation ofcollagen type III in the glomerulus specifically the mesangium and/or capillary walls. The puromcyin aminonucleoside (PAN) nephropathy model was evaluated to examine the relation between COL3A1 mRNA and proteinuria. [...] Read more.
Collagenofibrotic glomerulopathy, a collagen type III kidney disease, is associated with proteinuria and accumulation ofcollagen type III in the glomerulus specifically the mesangium and/or capillary walls. The puromcyin aminonucleoside (PAN) nephropathy model was evaluated to examine the relation between COL3A1 mRNA and proteinuria. In Wistar rats administered PAN, a robust increase in proteinuria was accompanied by glomerular hypertrophy and expansion of both the Bowman’s capsule and Bowman’s space. An ~4-fold increase in renal COL3A1 mRNA was observed in the PAN cohort with urine protein exhibiting a direct (r = 0.8) and significant correlation with kidney COL3A1 mRNA level. Both Picrosirius red polarized microscopy and immunohistochemical analysis showed localization of collagen type III to the glomerular mesangium. Gene ontology-driven transcriptomic analysis reveals a robust COL3A1 network in the glomerular compartment. Full article
(This article belongs to the Special Issue Drug Discovery and Delivery Processes)
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13 pages, 2116 KiB  
Article
Qualitative and Quantitative Analysis of Heavy Crude Oil Samples and Their SARA Fractions with 13C Nuclear Magnetic Resonance
by Ilfat Rakhmatullin, Sergey Efimov, Vladimir Tyurin, Marat Gafurov, Ameen Al-Muntaser, Mikhail Varfolomeev and Vladimir Klochkov
Processes 2020, 8(8), 995; https://doi.org/10.3390/pr8080995 - 16 Aug 2020
Cited by 24 | Viewed by 5009
Abstract
Nuclear magnetic resonance (NMR) approaches have unique advantages in the analysis of crude oil because they are non-destructive and provide information on chemical functional groups. Nevertheless, the correctness and effectiveness of NMR techniques for determining saturates, aromatics, resins, and asphaltenes (SARA analysis) without [...] Read more.
Nuclear magnetic resonance (NMR) approaches have unique advantages in the analysis of crude oil because they are non-destructive and provide information on chemical functional groups. Nevertheless, the correctness and effectiveness of NMR techniques for determining saturates, aromatics, resins, and asphaltenes (SARA analysis) without oil fractioning are still not clear. In this work we compared the measurements and analysis of high-resolution 13C NMR spectra in B0 ≈ 16.5 T (NMR frequency of 175 MHz) with the results of SARA fractioning for four various heavy oil samples with viscosities ranging from 100 to 50,000 mPa·s. The presence of all major hydrocarbon components both in crude oil and in each of its fractions was established quantitatively using NMR spectroscopy. Contribution of SARA fractions in the aliphatic (10–60 ppm) and aromatic (110–160 ppm) areas of the 13C NMR spectra were identified. Quantitative fractions of aromatic molecules and oil functional groups were determined. Aromaticity factor and the mean length of the hydrocarbon chain were estimated. The obtained results show the feasibility of 13C NMR spectroscopy for the express analysis of oil from physical properties to the composition of functional groups to follow oil treatment processes. Full article
(This article belongs to the Special Issue Heavy Oils Conversion Processes)
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28 pages, 2305 KiB  
Review
An Overview of Household Energy Consumption and Carbon Dioxide Emissions in Iran
by Omeid Rahmani, Shahabaldin Rezania, Amin Beiranvand Pour, Shahram M. Aminpour, Mohammad Soltani, Yousef Ghaderpour and Bahareh Oryani
Processes 2020, 8(8), 994; https://doi.org/10.3390/pr8080994 - 16 Aug 2020
Cited by 34 | Viewed by 8153
Abstract
This review tends to obtain a deeper understanding of the methods used in household energy consumption and carbon dioxide (CO2) emissions in Iran. Issues relating to energy consumption and CO2 emissions are very complex. This complexity arises from the fact [...] Read more.
This review tends to obtain a deeper understanding of the methods used in household energy consumption and carbon dioxide (CO2) emissions in Iran. Issues relating to energy consumption and CO2 emissions are very complex. This complexity arises from the fact that energy demand and energy consumption in Iran are influenced by many factors, such as income, household size, age, and gender. In Iran, the relevant energy sources mostly include liquefied petroleum gas (LPG) and electricity, which are used for different sectors, such as transportation, industry, and residential. This overview looks at both the theories and empirical studies of household energy consumption and CO2 emissions in Iran. Since energy consumption typically results in air pollution, it is often used as an indicator of environmental degradation. Although Iran is recently faced to energy efficiency improvement from all sectors, household energy requirements have been significantly increased. In Iran, a prime motivator had been improving living standards. As Iran gradually turns into a consumer society, households have an enormous influence on the direct use of energy and related CO2 emissions as well as through indirect use, as embodied in goods and services. The findings of this study can help policymakers to focus on renewable energy projects in order to reduce energy consumption and mitigate CO2 emissions. Full article
(This article belongs to the Section Environmental and Green Processes)
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19 pages, 1532 KiB  
Review
Technical Aspects of Biofuel Production from Different Sources in Malaysia—A Review
by Shahabaldin Rezania, Bahareh Oryani, Jinwoo Cho, Farzaneh Sabbagh, Parveen Fatemeh Rupani, Amirreza Talaiekhozani, Negar Rahimi and Majid Lotfi Ghahroud
Processes 2020, 8(8), 993; https://doi.org/10.3390/pr8080993 - 16 Aug 2020
Cited by 23 | Viewed by 6773
Abstract
Due to the depletion of fossil fuels, biofuel production from renewable sources has gained interest. Malaysia, as a tropical country with huge resources, has a high potential to produce different types of biofuels from renewable sources. In Malaysia, biofuels can be produced from [...] Read more.
Due to the depletion of fossil fuels, biofuel production from renewable sources has gained interest. Malaysia, as a tropical country with huge resources, has a high potential to produce different types of biofuels from renewable sources. In Malaysia, biofuels can be produced from various sources, such as lignocellulosic biomass, palm oil residues, and municipal wastes. Besides, biofuels are divided into two main categories, called liquid (bioethanol and biodiesel) and gaseous (biohydrogen and biogas). Malaysia agreed to reduce its greenhouse gas (GHG) emissions by 45% by 2030 as they signed the Paris agreement in 2016. Therefore, we reviewed the status and potential of Malaysia as one of the main biofuel producers in the world in recent years. The role of government and existing policies have been discussed to analyze the outlook of the biofuel industries in Malaysia. Full article
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19 pages, 9567 KiB  
Article
Experimental and Numerical Investigation on Improved Design for Profiled Freezing-tube of FSPR
by Yin Duan, Chuanxin Rong, Hua Cheng, Haibing Cai, Zongjin Wang and Zhishu Yao
Processes 2020, 8(8), 992; https://doi.org/10.3390/pr8080992 - 15 Aug 2020
Cited by 4 | Viewed by 2464
Abstract
The freeze-sealing pipe roof (FSPR) method, which combines the pipe roof method (PRM) with the artificial ground freezing (AGF) method, has been successfully utilized for the first time in the Gongbei Tunnel Project in China. During the construction process, there have been practical [...] Read more.
The freeze-sealing pipe roof (FSPR) method, which combines the pipe roof method (PRM) with the artificial ground freezing (AGF) method, has been successfully utilized for the first time in the Gongbei Tunnel Project in China. During the construction process, there have been practical problems such as difficulty in welding of the profiled freezing-tube, easy leakage of refrigerant, and working environment pollution, which bring difficulties to the tunnel construction and may affect the further promotion of this new method in the future. To address these problems, a method of placing double circular freezing-tubes on the inner wall of the hollow pipe and wrapped with cement mortar was put forward to replace the welding profiled freezing-tube in the actual project. By designing a scaled model test, the feasibility and freezing effect of this improved design were verified. The corresponding numerical calculation model was established to study the distribution characteristics and differences of temperature field under two different configurations. The research results show that the Configuration 2, with the improved design, presents a lower temperature and a higher cooling rate; the limiting-tube could limit the excessive development of the frozen soil wall within a certain range, to avoid the adverse impact of frost heave on the ground building structure. Under the premise of meeting the design requirements for freezing, the freezing time of Configuration 2 at the centerline between the pipes and the vertical line of the hollow pipe is 33% and 46% shorter than that of Configuration 1, respectively. Finally, the average thickness of the frozen soil wall at the right side of the hollow pipe, the vertical direction of the hollow pipe, and between the pipes increased 33%, 17%, and 13% in Configuration 2, respectively. The improved design proposed in this paper is not only more convenient in production and installation but is also demonstrated to provide improved freezing effects, providing a strong guarantee for the further popularization and application of the freeze-sealing pipe roof method. Full article
(This article belongs to the Section Process Control and Monitoring)
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14 pages, 5572 KiB  
Article
The Effect of Wettability and Flow Rate on Oil Displacement Using Polymer-Coated Silica Nanoparticles: A Microfluidic Study
by Mohamed Omran, Salem Akarri and Ole Torsaeter
Processes 2020, 8(8), 991; https://doi.org/10.3390/pr8080991 - 15 Aug 2020
Cited by 31 | Viewed by 5126
Abstract
Polymer-coated silica nanoparticles (PSiNPs) have been experimentally investigated in core- and micro-scale studies for enhanced oil recovery (EOR). Wettability and flow rate have a considerable effect on oil displacement in porous media. This work investigates the efficiency of PSiNPs for oil recovery on [...] Read more.
Polymer-coated silica nanoparticles (PSiNPs) have been experimentally investigated in core- and micro-scale studies for enhanced oil recovery (EOR). Wettability and flow rate have a considerable effect on oil displacement in porous media. This work investigates the efficiency of PSiNPs for oil recovery on micro-scale at three wettability states (water-wet, intermediate-wet, and oil-wet). In addition, a cluster mobilization regime is considered in all experiments. A microfluidic approach was utilized to perform flooding experiments with constant experimental settings such as flowrate, pore-structure, initial oil topology, porosity, and permeability. In this study, the wettability of the microfluidic chips was altered to have three states of wettability. Firstly, a micro-scale study (brine-oil-glass system) of each wettability condition effect on flow behavior was conducted via monitoring dynamic changes in the oleic phase. Secondly, the obtained results were used as a basis to understand the changes induced by the PSiNPs while flooding at the same conditions. The experimental data were extracted by means of image processing and analysis at a high spatial and temporal resolution. Low injection rate experiments (corresponding to ~1.26 m/day in reservoir) in a brine-oil-glass system showed that the waterflood invaded with a more stable front with a slower displacement velocity in the water-wet state compared to the other states, which had water channeling through the big pores. As a result, a faster stop of the dynamic changes for the intermediate- and oil-wet state was observed, leading to lower oil recoveries compared to the water-wet state. In a cluster mobilization regime, dynamic changes were noticeable only for the oil-wet condition. For the aforementioned different conditions, PSiNPs improved oil displacement efficiency. The usage of PSiNPs showed a better clusterization efficiency, leading to a higher mobilization, smaller remaining oil clusters, and lower connectivity of the residual oil. The knowledge from this experimental work adds to the understanding of the behavior of polymer-coated silica nanoparticles as a recovery agent at different wettability states and a cluster mobilization regime. Full article
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20 pages, 4230 KiB  
Article
Performance, Emissions, Combustion and Vibration Analysis of a CI Engine Fueled with Coconut and Used Palm Cooking Oil Methyl Ester
by Yew Heng Teoh, Heoy Geok How, Navaneetha Krishnan Balakrishnan, Thanh Danh Le and Huu Tho Nguyen
Processes 2020, 8(8), 990; https://doi.org/10.3390/pr8080990 - 15 Aug 2020
Cited by 3 | Viewed by 3806
Abstract
Biodiesels from coconut and palm cooking oil are viable alternatives to diesel fuel due to their environmental sustainability and similar physicochemical properties compared to diesel. In the present study, these fuels were tested separately in a diesel engine by blending with fossil diesel [...] Read more.
Biodiesels from coconut and palm cooking oil are viable alternatives to diesel fuel due to their environmental sustainability and similar physicochemical properties compared to diesel. In the present study, these fuels were tested separately in a diesel engine by blending with fossil diesel in proportions of 10%, 20%, 30% and 40% by volume. Experiments were conducted under a constant brake mean effective pressure (BMEP) of 400 kPa and at 2000 rpm. The results revealed similarities in engine performance, emissions, combustion and engine block vibration for used palm cooking oil methyl ester (UPME) fuel blends and coconut methyl ester (CME) fuel blends. Most blends resulted in slight improvements in brake specific energy consumption (BSEC) and brake thermal efficiency (BTE). A maximum reduction of 54%, 89% and 16.8% in pollutant emissions of brake specific hydrocarbons (BSHC), brake specific carbon monoxide (BSCO) and brake specific nitrogen oxides (BSNOx), respectively, was observed with UPME and CME in the blends. The cylinder pressure profiles when UPME-diesel and CME-diesel blends were used were comparable to a standard diesel pressure trace, however, some deviations in peak pressure were also noticed. It was also apparent from the results that engine vibration was influenced by the type of methyl ester used and its blend composition. Notably, the rate of pressure increase was maintained within an acceptable limit when the engine was fueled with both of the methyl ester blends. Full article
(This article belongs to the Special Issue Progress in Energy Conversion Systems and Emission Control)
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20 pages, 2464 KiB  
Article
Tetracycline Induces the Formation of Biofilm of Bacteria from Different Phases of Wastewater Treatment
by Tereza Stachurová, Kateřina Malachová, Jaroslav Semerád, Meta Sterniša, Zuzana Rybková and Sonja Smole Možina
Processes 2020, 8(8), 989; https://doi.org/10.3390/pr8080989 - 14 Aug 2020
Cited by 6 | Viewed by 4410
Abstract
The study monitored the effect of tetracycline on bacterial biofilm formation and compared biofilm formation by resistant bacterial strains in different phases of the wastewater treatment process in wastewater treatment plant (WWTP). The crystal violet staining method was used to evaluate the biofilm [...] Read more.
The study monitored the effect of tetracycline on bacterial biofilm formation and compared biofilm formation by resistant bacterial strains in different phases of the wastewater treatment process in wastewater treatment plant (WWTP). The crystal violet staining method was used to evaluate the biofilm formation. Biofilm-related bacterial properties were characterized by hydrophobicity, autoaggregation and motility tests. The relative abundance of tetracycline resistance genes (tetW, tetM, tetO, tetA and tetB) in wastewaters were subsequently quantified using qPCR. The results show that the isolates from the nitrification tank produce biofilm with up to 10 times greater intensity relative to the isolates from the sedimentation tank. In isolates of Aeromonas sp. from the nitrification tank, increased biofilm production in the occurrence of tetracycline from a concentration of 0.03125 µg/mL was observed. The tetW gene showed the highest relative abundance out of all the tested genes. From the sampling points, its abundance was the highest in the sedimentation tank of the WWTP. Based on these results, it can be assumed that resistant bacteria are able to form a biofilm and sub-inhibitory tetracycline concentrations induce biofilm formation. WWTPs thus represent a reservoir of antibiotic resistance genes and contribute to the spread of resistance in the natural environment. Full article
(This article belongs to the Special Issue Application of Microorganisms in Wastewater Treatment)
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20 pages, 849 KiB  
Review
Application of Novel Techniques for Monitoring Quality Changes in Meat and Fish Products during Traditional Processing Processes: Reconciling Novelty and Tradition
by Abdo Hassoun, María Guðjónsdóttir, Miguel A. Prieto, Paula Garcia-Oliveira, Jesus Simal-Gandara, Federico Marini, Francesca Di Donato, Angelo Antonio D’Archivio and Alessandra Biancolillo
Processes 2020, 8(8), 988; https://doi.org/10.3390/pr8080988 - 14 Aug 2020
Cited by 20 | Viewed by 7411
Abstract
In this review, we summarize the most recent advances in monitoring changes induced in fish and other seafood, and meat and meat products, following the application of traditional processing processes by means of conventional and emerging advanced techniques. Selected examples from the literature [...] Read more.
In this review, we summarize the most recent advances in monitoring changes induced in fish and other seafood, and meat and meat products, following the application of traditional processing processes by means of conventional and emerging advanced techniques. Selected examples from the literature covering relevant applications of spectroscopic methods (i.e., visible and near infrared (VIS/NIR), mid-infrared (MIR), Raman, nuclear magnetic resonance (NMR), and fluorescence) will be used to illustrate the topics covered in this review. Although a general reluctance toward using and adopting new technologies in traditional production sectors causes a relatively low interest in spectroscopic techniques, the recently published studies have pointed out that these techniques could be a powerful tool for the non-destructive monitoring and process optimization during the production of muscle food products. Full article
(This article belongs to the Collection Sustainable Food Processing Processes)
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18 pages, 5234 KiB  
Article
Distributed Optimization for Active Distribution Network Considering the Balance of Multi-Stakeholder
by Yang Liu, Sanming Liu and Zhuangzhuang Niu
Processes 2020, 8(8), 987; https://doi.org/10.3390/pr8080987 - 14 Aug 2020
Cited by 2 | Viewed by 2673
Abstract
Nowadays, distributed power generation is highly valued and fully developed since the energy crisis is worsening. At the same time, the distribution system operator is becoming a new stakeholder to take part in the dispatch of the active distribution network (ADN) with the [...] Read more.
Nowadays, distributed power generation is highly valued and fully developed since the energy crisis is worsening. At the same time, the distribution system operator is becoming a new stakeholder to take part in the dispatch of the active distribution network (ADN) with the power market being further reformed. Some new challenges to the dispatching of the ADN are brought by these distribution system operators (DSO), which break the traditional requirement of the lowest operating cost. In this paper, the relationship between the maximum revenue and the minimum operating cost of the ADN is fully considered, and the model of the bi-level distributed ADN considering the benefits and privacy protection of multi-stakeholder is established precisely. Further, the model is solved by using the alternating direction method of multipliers (ADMM) in which the safety and economy of the ADN are fully considered. Finally, the validity of the model and the feasibility of the algorithm are verified by using the adjusted IEEE 33 bus. Full article
(This article belongs to the Special Issue Power System Expansion Planning)
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18 pages, 1610 KiB  
Article
Magnetic Multiwall Carbon Nanotube Decorated with Novel Functionalities: Synthesis and Application as Adsorbents for Lead Removal from Aqueous Medium
by Ghadir Hanbali, Shehdeh Jodeh, Othman Hamed, Roland Bol, Bayan Khalaf, Asma Qdemat, Subhi Samhan and Omar Dagdag
Processes 2020, 8(8), 986; https://doi.org/10.3390/pr8080986 - 14 Aug 2020
Cited by 15 | Viewed by 3310
Abstract
Water pollution is one of the major challenges facing modern society because of industrial development and urban growth. This study is directed towards assessing the use of multiwall carbon nanotube, after derivatization and magnetization, as a new and renewable absorbent, to remove toxic [...] Read more.
Water pollution is one of the major challenges facing modern society because of industrial development and urban growth. This study is directed towards assessing the use of multiwall carbon nanotube, after derivatization and magnetization, as a new and renewable absorbent, to remove toxic metal ions from waste streams. The adsorbents were prepared by, first oxidation of multiwall carbon nanotube, then derivatizing the oxidized product with hydroxyl amine, hydrazine and amino acid. The adsorbents were characterized by various techniques. The adsorption efficiency of the multiwall carbon nanotube adsorbents toward Pb(II) was investigated. The effect of adsorbent’s dose, temperature, pH, and time on the adsorption efficiency were studied and the adsorption parameters that gave the highest efficiency were determined. The derivatives have unique coordination sites that included amine, hydroxyl, and carboxyl groups, which are excellent chelating agents for metal ions. The thermodynamic and kinetic results analysis results indicated spontaneous adsorption of Pb(II) by the multiwall carbon nanotube adsorbents at room temperature. The adsorption process followed pseudo-second-order and Langmuir isotherm model. The adsorbents were regenerated using 0.1 N HCl. Full article
(This article belongs to the Special Issue Various Adsorbents for Water Purification Processes)
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11 pages, 2778 KiB  
Article
Flow and Noise Characteristics of Centrifugal Fan in Low Pressure Environment
by Xilong Zhang, Yongliang Zhang and Chenggang Lu
Processes 2020, 8(8), 985; https://doi.org/10.3390/pr8080985 - 13 Aug 2020
Cited by 12 | Viewed by 5350
Abstract
The influence of low-pressure environment on centrifugal fan’s flow and noise characteristics was studied experimentally and numerically. A testbed was established to conduct the experimental test on the performance of a centrifugal fan, and the characteristic curve and power consumption curve of the [...] Read more.
The influence of low-pressure environment on centrifugal fan’s flow and noise characteristics was studied experimentally and numerically. A testbed was established to conduct the experimental test on the performance of a centrifugal fan, and the characteristic curve and power consumption curve of the fan under different pressure were obtained. Then the simulation model of the centrifugal fan was established, which was used to simulate the working process of centrifugal fan under different negative pressures. The results showed that the total pressure and static pressure of the fan decrease with the decrease of the ambient pressure. The total and static pressures of the fan under 60 kPa pressure condition decreased by 42.3% and 38.3%, respectively, compared with those of fan under the normal pressure. The main reason for this phenomenon is that the decrease of the environmental pressure leads to the decrease of air density. Besides, with the drop of environmental pressure, the sound pressure and sound power of the fan noise decreases. Full article
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42 pages, 8159 KiB  
Review
Solid Particle Erosion Behaviour and Protective Coatings for Gas Turbine Compressor Blades—A Review
by Jasem Alqallaf, Naser Ali, Joao A. Teixeira and Abdulmajid Addali
Processes 2020, 8(8), 984; https://doi.org/10.3390/pr8080984 - 13 Aug 2020
Cited by 68 | Viewed by 11271
Abstract
Gas turbines (GTEs) are often utilised in harsh environments where the GT components, including compressor vanes and rotor blades, are subject to erosion damage by sand and dust particles. For instance, in a desert environment, the rate of damage made by solid particles [...] Read more.
Gas turbines (GTEs) are often utilised in harsh environments where the GT components, including compressor vanes and rotor blades, are subject to erosion damage by sand and dust particles. For instance, in a desert environment, the rate of damage made by solid particles erosion (SPE) becomes severe, and therefore results in degradation to the GTE parts, lowering the cycle efficiency, reducing the device lifetime, and increasing the overall cost of the operation. As such, understanding the erosion mechanism caused by solid particles and the effects associated with it is crucial for selecting the appropriate countermeasures and maintaining the system performance. This review paper provides a survey of the available studies on SPE effects on GTEs and surface protective coatings. Firstly, the ductile and brittle SPE mechanism is presented, as well as the ductile-brittle transition region. Then, an in-depth focus on the parameters associated with the SPE, such as particles properties and impingement conditions, is introduced. Furthermore, the existing theoretical models are shown and discussed. Afterwards, erosion resistant coating materials for surface protection and their selection criteria are covered in the review. Finally, the gap in knowledge and future research direction in the field of SPE on GTEs are provided. Full article
(This article belongs to the Special Issue Feature Review Papers)
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19 pages, 6229 KiB  
Article
Material Point Method Simulation of the Equation of State of Polymer-Bonded Explosive under Impact Loading at Mesoscale
by Siyu Ge, Wenying Zhang, Jian Sang, Shuai Yuan, Glenn V. Lo and Yusheng Dou
Processes 2020, 8(8), 983; https://doi.org/10.3390/pr8080983 - 13 Aug 2020
Cited by 3 | Viewed by 3167
Abstract
Mesoscale simulation using the material point method (MPM) was conducted to study the pressure–volume (PV) variations of Octahydro-1,3,5,7-Tetranitro-1,2,3,5-Tetrazocine (HMX)/Estane polymer-bonded explosive (PBX) under impact loading. The PV isotherms and Hugoniot data were calculated for the different porosities and binder volume fractions. The PV [...] Read more.
Mesoscale simulation using the material point method (MPM) was conducted to study the pressure–volume (PV) variations of Octahydro-1,3,5,7-Tetranitro-1,2,3,5-Tetrazocine (HMX)/Estane polymer-bonded explosive (PBX) under impact loading. The PV isotherms and Hugoniot data were calculated for the different porosities and binder volume fractions. The PV isotherms were used to determine the parameters for the Birch– Murnaghan equation of state (EOS) for the PBX. From the EOS, the isothermal bulk modulus (K0) and its pressure derivative (K0) were calculated. Additionally, the pseudo particle velocity and pseudo shock velocity variations were used to obtain the bulk wave speed c and dimensionless coefficient s for the Mie–Grüneisen EOS. The simulations provide an alternative approach for determining an EOS that is consistent with experimental observations. Full article
(This article belongs to the Special Issue Simulation for Analyzing Particle Behavior)
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38 pages, 1485 KiB  
Review
A General Review of the Current Development of Mechanically Agitated Vessels
by Marek Jaszczur and Anna Młynarczykowska
Processes 2020, 8(8), 982; https://doi.org/10.3390/pr8080982 - 13 Aug 2020
Cited by 36 | Viewed by 10107
Abstract
The mixing process in a mechanically agitated vessel is a widespread phenomenon which plays an important role among industrial processes. In that process, one of the crucial parameters, the mixing efficiency, depends on a large number of geometrical factors, as well as process [...] Read more.
The mixing process in a mechanically agitated vessel is a widespread phenomenon which plays an important role among industrial processes. In that process, one of the crucial parameters, the mixing efficiency, depends on a large number of geometrical factors, as well as process parameters and complex interactions between the phases which are still not well understood. In the last decade, large progress has been made in optimisation, construction and numerical and experimental analysis of mechanically agitated vessels. In this review, the current state in this field has been presented. It shows that advanced computational fluid dynamic techniques for multiphase flow analysis with reactions and modern experimental techniques can be used with success to analyse in detail mixing features in liquid-liquid, gas-liquid, solid-liquid and in more than two-phase flows. The objective is to show the most important research recently carried out. Full article
(This article belongs to the Special Issue Advances in the Chemical Mixing Process)
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14 pages, 2318 KiB  
Review
N-Tosylcarboxamide in C–H Functionalization: More than a Simple Directing Group
by Benjamin Large, Vincent Terrasson and Damien Prim
Processes 2020, 8(8), 981; https://doi.org/10.3390/pr8080981 - 13 Aug 2020
Cited by 3 | Viewed by 2329
Abstract
C–H activation with transition metal catalysis has become an important tool in organic synthesis for the functionalization of low reactive bonds and the preparation of complex molecules. The choice of the directing group (DG) proves to be crucial for the selectivity in this [...] Read more.
C–H activation with transition metal catalysis has become an important tool in organic synthesis for the functionalization of low reactive bonds and the preparation of complex molecules. The choice of the directing group (DG) proves to be crucial for the selectivity in this type of reaction, and several different functional groups have been used efficiently. This review describes recent advances in C–H functionalization of aromatic rings directed by a N-tosylcarboxamide group. Results regarding alkenylation, alkoxylation, halogenation, and arylation of C–H in the ortho position to the tosylcarboxamide are presented. Moreover, the advantage of this particular directing group is that it can undergo further transformation and act as CO or CON fragment reservoir to produce, in sequential fashion or one-pot sequence, various interesting (hetero)cycles such as phenanthridinones, dihydroisoquinolinones, fluorenones, or isoindolinones. Full article
(This article belongs to the Special Issue Recent Advances in Catalysis by Transition Metals)
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19 pages, 2838 KiB  
Article
Grand Tour Algorithm: Novel Swarm-Based Optimization for High-Dimensional Problems
by Gustavo Meirelles, Bruno Brentan, Joaquín Izquierdo and Edevar Luvizotto, Jr.
Processes 2020, 8(8), 980; https://doi.org/10.3390/pr8080980 - 13 Aug 2020
Cited by 8 | Viewed by 2749
Abstract
Agent-based algorithms, based on the collective behavior of natural social groups, exploit innate swarm intelligence to produce metaheuristic methodologies to explore optimal solutions for diverse processes in systems engineering and other sciences. Especially for complex problems, the processing time, and the chance to [...] Read more.
Agent-based algorithms, based on the collective behavior of natural social groups, exploit innate swarm intelligence to produce metaheuristic methodologies to explore optimal solutions for diverse processes in systems engineering and other sciences. Especially for complex problems, the processing time, and the chance to achieve a local optimal solution, are drawbacks of these algorithms, and to date, none has proved its superiority. In this paper, an improved swarm optimization technique, named Grand Tour Algorithm (GTA), based on the behavior of a peloton of cyclists, which embodies relevant physical concepts, is introduced and applied to fourteen benchmarking optimization problems to evaluate its performance in comparison to four other popular classical optimization metaheuristic algorithms. These problems are tackled initially, for comparison purposes, with 1000 variables. Then, they are confronted with up to 20,000 variables, a really large number, inspired in the human genome. The obtained results show that GTA clearly outperforms the other algorithms. To strengthen GTA’s value, various sensitivity analyses are performed to verify the minimal influence of the initial parameters on efficiency. It is demonstrated that the GTA fulfils the fundamental requirements of an optimization algorithm such as ease of implementation, speed of convergence, and reliability. Since optimization permeates modeling and simulation, we finally propose that GTA will be appealing for the agent-based community, and of great help for a wide variety of agent-based applications. Full article
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15 pages, 2307 KiB  
Article
Residue Char Derived from Microwave-Assisted Pyrolysis of Sludge as Adsorbent for the Removal of Methylene Blue from Aqueous Solutions
by Gong Cheng, Yazhuo Li, Liming Sun, Siyi Luo, George Z. Kyzas and Jie Fu
Processes 2020, 8(8), 979; https://doi.org/10.3390/pr8080979 - 13 Aug 2020
Cited by 2 | Viewed by 2727
Abstract
Residue char is the main by-product of the microwave-assisted pyrolysis of activated sludge and it has a high content of fixed carbon and porous structure, but little is known about its character as an absorbent. In this study, residue char of activated sludge [...] Read more.
Residue char is the main by-product of the microwave-assisted pyrolysis of activated sludge and it has a high content of fixed carbon and porous structure, but little is known about its character as an absorbent. In this study, residue char of activated sludge with microwave-assisted pyrolysis was used as an adsorbent to absorb methylene blue. The effects of pyrolysis temperature, pyrolysis holding time, contact time, and adsorption temperature on the adsorption ability of residue char were investigated. Kinetics, isotherm, and thermodynamic models were also included to study the adsorption behavior. The results showed that the optimal pyrolysis condition was 15 min and 603 °C, and the adsorption capacity reached up to 80.01 mg/g. The kinetics analyses indicated the adsorption behavior followed the pseudo-second-order kinetics model and the adsorption process was mainly due to chemical interaction. The adsorption isotherm was described by Freundlich model and thus, its process was multimolecular layer adsorption. Furthermore, the thermodynamics parameters (ΔG0, ΔH0, and ΔS0) at different temperatures indicated that the nature of the adsorption process was endothermic and spontaneous. Full article
(This article belongs to the Special Issue Redesign Processes in the Age of the Fourth Industrial Revolution)
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14 pages, 1528 KiB  
Article
Comparative Study of Angiotensin I-Converting Enzyme (ACE) Inhibition of Soy Foods as Affected by Processing Methods and Protein Isolation
by Cíntia L. Handa, Yan Zhang, Shweta Kumari, Jing Xu, Elza I. Ida and Sam K. C. Chang
Processes 2020, 8(8), 978; https://doi.org/10.3390/pr8080978 - 12 Aug 2020
Cited by 13 | Viewed by 4379
Abstract
Angiotensin converting enzyme (ACE) converts angiotensin I into the vasoconstrictor angiotensin II and eventually elevates blood pressure. High blood pressure is a major risk factor for heart disease and stroke. Studies show peptides present anti-hypertensive activity by ACE inhibition. During food processing and [...] Read more.
Angiotensin converting enzyme (ACE) converts angiotensin I into the vasoconstrictor angiotensin II and eventually elevates blood pressure. High blood pressure is a major risk factor for heart disease and stroke. Studies show peptides present anti-hypertensive activity by ACE inhibition. During food processing and digestion, food proteins may be hydrolyzed and release peptides. Our objective was to determine and compare the ACE inhibitory potential of fermented and non-fermented soy foods and isolated 7S and 11S protein fractions. Soy foods (e.g., soybean, natto, tempeh, yogurt, soymilk, tofu, soy-sprouts) and isolated proteins were in vitro digested prior to the determination of ACE inhibitory activity. Peptide molecular weight distribution in digested samples was analyzed and correlated with ACE inhibitory capacity. Raw and cooked soymilk showed the highest ACE inhibitory potential. Bacteria-fermented soy foods had higher ACE inhibitory activity than fungus-fermented soy food, and 3 day germinated sprouts had higher ACE inhibition than those germinated for 5 and 7 days. The 11S hydrolysates showed higher ACE inhibitory capacity than 7S. Peptides of 1–4.5 kDa showed a higher contribution to reducing IC50. This study provides evidence that soy foods and isolated 7S and 11S proteins may be used as functional foods or ingredients to prevent or control hypertension. Full article
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14 pages, 641 KiB  
Review
Tracing the Scientific History of Fe0-Based Environmental Remediation Prior to the Advent of Permeable Reactive Barriers
by Viet Cao, Huichen Yang, Arnaud Igor Ndé-Tchoupé, Rui Hu, Willis Gwenzi and Chicgoua Noubactep
Processes 2020, 8(8), 977; https://doi.org/10.3390/pr8080977 - 12 Aug 2020
Cited by 17 | Viewed by 3152
Abstract
The technology of using metallic iron (Fe0) for in situ generation of iron oxides for water treatment is a very old one. The Fe0 remediation technology has been re-discovered in the framework of groundwater remediation using permeable reactive barriers (PRBs). [...] Read more.
The technology of using metallic iron (Fe0) for in situ generation of iron oxides for water treatment is a very old one. The Fe0 remediation technology has been re-discovered in the framework of groundwater remediation using permeable reactive barriers (PRBs). Despite its simplicity, the improvement of Fe0 PRBs is fraught with difficulties regarding their operating modes. The literature dealing with Fe0 remediation contains ambiguities regarding its invention and its development. The present paper examines the sequence of contributions prior to the advent of Fe0 PRBs in order to clarify the seemingly complex picture. To achieve this, the current paper addresses the following questions: (i) What were the motivations of various authors in developing their respective innovations over the years?, (ii) what are the ancient achievements which can accelerate progress in knowledge for the development of Fe0 PRBs?, and (iii) was Fe0 really used for the removal of organic species for the first time in the 1970s? A careful examination of ancient works reveals that: (i) The wrong questions were asked during the past three decades, as Fe0 was premised as a reducing agent, (ii) credit for using Fe0 for water treatment belongs to no individual scientist, and (iii) credit for the use of Fe0 in filtration systems for safe drinking water provision belongs to scientists from the 1850s, while credit for the use of Fe0 for the removal of aqueous organic species does not belong to the pioneers of the Fe0 PRB technology. However, it was these pioneers who exploited Fe0 for groundwater remediation, thereby extending its potential. Complementing recent achievements with the chemistry of the Fe0/H2O system would facilitate the design of more sustainable Fe0-remediation systems. Full article
(This article belongs to the Section Environmental and Green Processes)
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