Records Added in May 2021
Records added in May 2021
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Showing records 1 to 25 of 160. [First] Page: 1 2 3 4 5 Last
Chemical Characterization Using Different Analytical Techniques to Understand Processes: The Case of the Paraffinic Base Oil Production Line
Rémi Moulian, Johann Le Maître, Hélène Leroy, Ryan Rodgers, Brice Bouyssiere, Carlos Afonso, Pierre Giusti, Caroline Barrère-Mangote
May 28, 2021 (v1)
Subject: Materials
Keywords: APPI FT ICR MS, aromatics, GPC ICP HRMS, HPLC3, lubricant base oil, viscosity
Mineral base oils are used to produce commercial lubricants and are obtained from refining vacuum residue. Lubricants are used to reduce friction in industry devices, so their viscosity is a key characteristic that needs to be optimized throughout the process. The purpose of this study is to show how global chemical characterization of samples from the base oil production chain can facilitate a better understanding of the molecular impacts of processing and their effect on macroscopic properties like viscosity. Eight different samples were characterized by different analytical techniques, including liquid chromatography and mass spectrometry techniques, to understand their chemical evolution through the different process units at the molecular level. Furthermore, a statistical treatment allowed for the identification of parameters that influence viscosity, mainly sulfur and polyaromatics content. This study demonstrates the importance and effectiveness of cross-checking results from di... [more]
Adjusting Organic Load as a Strategy to Direct Single-Stage Food Waste Fermentation from Anaerobic Digestion to Chain Elongation
Vicky De Groof, Marta Coma, Tom C. Arnot, David J. Leak, Ana B. Lanham
May 28, 2021 (v1)
Keywords: acidogenic fermentation, anaerobic digestion, food waste, medium chain carboxylic acids, microbial chain elongation, mixed culture, organic loading rate
Production of medium chain carboxylic acids (MCCA) as renewable feedstock bio-chemicals, from food waste (FW), requires complicated reactor configurations and supplementation of chemicals to achieve product selectivity. This study evaluated the manipulation of organic loading rate in an un-supplemented, single stage stirred tank reactor to steer an anaerobic digestion (AD) microbiome towards acidogenic fermentation (AF), and thence to chain elongation. Increasing substrate availability by switching to a FW feedstock with a higher COD stimulated chain elongation. The MCCA species n-caproic (10.1 ± 1.7 g L−1) and n-caprylic (2.9 ± 0.8 g L−1) acid were produced at concentrations comparable to more complex reactor set-ups. As a result, of the adjusted operating strategy, a more specialised microbiome developed containing several MCCA-producing bacteria, lactic acid-producing Olsenella spp. and hydrogenotrophic methanogens. By contrast, in an AD reactor that was operated in parallel to prod... [more]
Insights on Monosaccharides and Bioethanol Production from Sweet Sorghum Stalks Using Dilute Acid Pretreatment
Cristian-Teodor Buruiană, Luminița Georgescu, Simona-Florina Isticioaia, Oana Emilia Constantin, Camelia Vizireanu, Rodica Mihaela Dinică, Bianca Furdui
May 28, 2021 (v1)
Keywords: bioethanol production, dilute acid pretreatment, monosaccharides, simultaneous saccharification and fermentation, sweet sorghum stalks
Sweet sorghum is a unique bioenergy crop that produces stalks with fermentable free sugars. The purpose of this study was to evaluate how the production of hemicellulosic saccharides and bioethanol from sweet sorghum stalks (SSS) can be influenced by a dilute sulfuric acid (H2SO4) pretreatment under different isothermal conditions. The bioethanol production from untreated SSS and pretreated solid phases was achieved through the Simultaneous Saccharification and Fermentation (SSF) process. A good SSS fractionation and an extensive hemicellulose hydrolysis into soluble saccharides were obtained, the most abundant hemicellulose-derived compounds present in the pretreated liquid phase being monosaccharides, with up to 17.22 g/L of glucose and 16.64 g/L of xylose in the pretreatments performed with 3% and 1% H2SO4 for 30 min at 134 °C, respectively. The SSF process of untreated SSS allowed a maximum bioethanol concentration of 9.78 g/L, corresponding to a maximum glucan conversion into etha... [more]
Optimising Brewery-Wastewater-Supported Acid Mine Drainage Treatment vis-à-vis Response Surface Methodology and Artificial Neural Network
Enoch A. Akinpelu, Seteno K. O. Ntwampe, Abiola E. Taiwo, Felix Nchu
May 28, 2021 (v1)
Keywords: acid mine drainage, artificial neural network, brewing wastewater, optimisation, response surface methodology, sulphate reduction
This study investigated the use of brewing wastewater (BW) as the primary carbon source in the Postgate medium for the optimisation of sulphate reduction in acid mine drainage (AMD). The results showed that the sulphate-reducing bacteria (SRB) consortium was able to utilise BW for sulphate reduction. The response surface methodology (RSM)/Box−Behnken design optimum conditions found for sulphate reduction were a pH of 6.99, COD/SO42− of 2.87, and BW concentration of 200.24 mg/L with predicted sulphate reduction of 91.58%. Furthermore, by using an artificial neural network (ANN), a multilayer full feedforward (MFFF) connection with an incremental backpropagation network and hyperbolic tangent as the transfer function gave the best predictive model for sulphate reduction. The ANN optimum conditions were a pH of 6.99, COD/SO42− of 0.50, and BW concentration of 200.31 mg/L with predicted sulphate reduction of 89.56%. The coefficient of determination (R2) and absolute average deviation (AAD)... [more]
Carbonaceous Adsorbent Derived from Sulfur-Impregnated Heavy Oil Ash and Its Lead Removal Ability from Aqueous Solution
Takaaki Wajima
May 28, 2021 (v1)
Keywords: heavy oil ash, K2S immerse, lead removal, pyrolysis, selectivity
A novel carbonaceous adsorbent was prepared from sulfur-impregnated heavy oil ash via pyrolysis using potassium sulfide (K2S) solution, and its ability to remove lead (Pb2+) from aqueous solutions was examined. It was compared with an adsorbent synthesized by conventional pyrolysis using potassium hydroxide (KOH) solution. Specifically, the raw ash was immersed in 1 M K2S solution or 1 M KOH solution for 1 day and subsequently heated at 100−1000 °C in a nitrogen (N2) atmosphere. After heating for 1 h, the solid was naturally cooled in N2 atmosphere, and subsequently washed and dried to yield the product. Regardless of the pyrolysis temperature, the product generated using K2S (Product-K2S) has a higher sulfur content than that obtained using KOH (Product-KOH). Moreover, Product-K2S has a higher lead removal ability than Product-KOH, whereas the specific surface area of the former is smaller than that of the latter. Product-K2S obtained at 300 °C (Product-K2S-300) achieves the highest l... [more]
Improved Phenolic Compositions and Sensory Attributes of Red Wines by Saccharomyces cerevisiae Mutant CM8 Overproducing Cell-Wall Mannoproteins
Phoency F.-H. Lai, Po-Chun Hsu, Bo-Kang Liou, Rupesh D. Divate, Pei-Ming Wang, Yun-Chin Chung
May 28, 2021 (v1)
Keywords: consumer preference, kyoho grape, mannoprotein, Saccharomyces cerevisiae, wine
The objective of this study was to improve the quality attributes of red wines by Saccharomyces cerevisiae (BCRC 21685) mutant CM8 with overexpression of high-mannose mannoproteins, with respective to phenolic compositions, colorimetric parameters, and consumer sensory attributes. The CM8 was mutated by ethyl methane sulfonate and showed the ability of overproducing cell wall mannoproteins selected by killer-9 toxin-containing YPD plates. Kyoho grapes were used as raw materials. It is interesting to find that the cell wall mannoproteins isolated from CM8 mutant possessed a significantly higher mannose content in the polysaccharide fraction (81% w/w) than that did from parent strain (66% w/w). The red wines made of winter grapes and CM8 (CM8-WIN) showed significantly greater total tannins, flavonols, and anthocyanins levels, as well as higher color, higher flavor, and higher consumer preference than those by its SC counterpart (SC-WIN). The characteristics of the red wines studied were... [more]
Multiple Criteria Decision-Making: A Novel Applications of Network DEA Model
Chang-Hsu Chen, Wen-Bin Lin, Shih-Chieh Yang, Richard Hsiao
May 28, 2021 (v1)
Subject: Other
Keywords: aboriginals, efficiency, ex-member, multi-criteria decision making, Taiwanese coaches
Do retired professional baseball players become effective coaches? Are Taiwanese coaches up to the job of coaching in the Chinese Professional Baseball League (CPBL)? What are the key coaching factors affecting a CPBL team’s performance in the regular-season? In this study, we examine the key coaching factors affecting the efficiency of CPBL teams from the perspective of efficiency and productivity, using network data envelopment analysis, truncated regression analysis, and bootstrapping methods to provide specific recommendations. We calculated the efficiency of each CPBL team from the 2014 to 2016 regular-seasons. First, the “ex-member” indicator had a significant negative impact on team performance, indicating that a coaching team consisting of coaches with different backgrounds or experience is advantageous to a team’s performance in games; and second, the “ex-professional player” indicator had a significant impact on team performance in the regular season, indicating that the valu... [more]
Bactericidal and Virucidal Efficacies and Safety of Puriton®
So-Hyeon Bok, Min-Hee Kim, Soon-Young Lee, Chun-Sik Bae, Min-Jae Lee, Kwang-Ho Kim, Dae-Hun Park
May 27, 2021 (v1)
Subject: Biosystems
Keywords: bactericidal, mineral mixture, Puriton®, safety, virucidal
In 2016, infectious microbes were one of the leading causes of death, especially in developing countries. Puriton® is a mineral mixture consisting of biotite, kaolinite, montmorillonite, serpentine, clinochlore, and vermiculite, and evaluated antimicrobial activity in vitro and safety in vivo. Nine pathogens and opportunistic bacteria, namely Salmonella typhimurium, Escherichia coli, Pseudomonas aeruginosa, Alcaligenes faecalis, Staphylococcus aureus, Enterococcus faecalis, Micrococcus luteus, Mycobacterium smegmatis, and Bacillus subtilis, and the two viruses Zika and Influenza A/Duck/MN/1525/81 were used. A 26-week oral repeated safety study of Puriton® was conducted. Puriton® suppressed the bacterial proliferation, with a minimum proliferative rate of 91.1% in B. subtilis ATCC6633. The virucidal efficacy of Puriton® against Zika virus after 4 h and 18 h of contact time was significant in all groups treated with Puriton®. Twenty-six-week repeated oral administration of Puriton® was c... [more]
A Wavelet Transform-Assisted Convolutional Neural Network Multi-Model Framework for Monitoring Large-Scale Fluorochemical Engineering Processes
Xintong Li, Kun Zhou, Feng Xue, Zhibing Chen, Zhiqiang Ge, Xu Chen, Kai Song
May 27, 2021 (v1)
Keywords: convolutional neural network (CNN), deep learning, fault detection and diagnosis (FDD), fluorochemical engineering processes, wavelet transform
The barely satisfactory monitoring situation of the hypertoxic fluorochemical engineering processes requires the application of advanced strategies. In order to deal with the non-linear mechanism of the processes and the highly complicated correlation among variables, a wavelet transform-assisted convolutional neural network (CNN) based multi-model dynamic monitoring method was proposed. A preliminary CNN model was first trained to detect faults and to diagnose part of them with minimum computational burden and time delay. Then, a wavelet assisted secondary CNN model was trained to diagnose the remaining faults with the highest possible accuracy. In this step, benefitting from the scale decomposition capabilities of the wavelet transform function, the inherent noise and redundant information could be filtered out and the useful signal was transformed into a higher compact space. In this space, a well-designed secondary CNN model was trained to further improve the fault diagnosis perfor... [more]
Tetracycline and Sulfonamide Antibiotics in Soils: Presence, Fate and Environmental Risks
Manuel Conde-Cid, Avelino Núñez-Delgado, María José Fernández-Sanjurjo, Esperanza Álvarez-Rodríguez, David Fernández-Calviño, Manuel Arias-Estévez
May 27, 2021 (v1)
Keywords: Adsorption, crops, degradation, desorption, food chain, microorganisms, transport, veterinary antibiotics, water bodies
Veterinary antibiotics are widely used worldwide to treat and prevent infectious diseases, as well as (in countries where allowed) to promote growth and improve feeding efficiency of food-producing animals in livestock activities. Among the different antibiotic classes, tetracyclines and sulfonamides are two of the most used for veterinary proposals. Due to the fact that these compounds are poorly absorbed in the gut of animals, a significant proportion (up to ~90%) of them are excreted unchanged, thus reaching the environment mainly through the application of manures and slurries as fertilizers in agricultural fields. Once in the soil, antibiotics are subjected to a series of physicochemical and biological processes, which depend both on the antibiotic nature and soil characteristics. Adsorption/desorption to soil particles and degradation are the main processes that will affect the persistence, bioavailability, and environmental fate of these pollutants, thus determining their potent... [more]
Quantitative Methods to Support Data Acquisition Modernization within Copper Smelters
Alessandro Navarra, Ryan Wilson, Roberto Parra, Norman Toro, Andrés Ross, Jean-Christophe Nave, Phillip J. Mackey
May 27, 2021 (v1)
Keywords: adaptive finite differences, copper smelter, discrete event simulation, Industry 4.0, matte-slag chemistry, nickel-copper smelter, Peirce-smith converting, radiometric sensors
Sensors and process control systems are essential for process automation and optimization. Many sectors have adapted to the Industry 4.0 paradigm, but copper smelters remain hesitant to implement these technologies without appropriate justification, as many critical functions remain subject to ground operator experience. Recent experiments and industrial trials using radiometric optoelectronic data acquisition, coupled with advanced quantitative methods and expert systems, have successfully distinguished between mineral species in reactive vessels with high classification rates. These experiments demonstrate the increasing potential for the online monitoring of the state of a charge in pyrometallurgical furnaces, allowing data-driven adjustments to critical operational parameters. However, the justification to implement an innovative control system requires a quantitative framework that is conducive to multiphase engineering projects. This paper presents a unified quantitative framewor... [more]
Optimizing Xylindein from Chlorociboria spp. for (Opto)electronic Applications
R.C. Van Court, Gregory Giesbers, Oksana Ostroverkhova, Seri C. Robinson
May 27, 2021 (v1)
Subject: Materials
Keywords: (opto)electronics, Chlorociboria, fungal pigment, green energy, organic semiconductor, secondary metabolites, spalting
Xylindein, a stable quinonic blue-green fungal pigment, has shown potential for use not only as a colorant but also as an (opto)electronic material. As no method presently exists to synthesize the pigment, organic production by slow-growing fungi from the genus Chlorociboria is the only method to obtain it. This has resulted in limited quantities of impure xylindein, hampering research. In order to improve quantity and quality of pigment for optoelectronic applications, speed of xylindein production by Chlorociboria aeruginosa and its relative purity were compared across liquid and solid-state fermentation conditions on selected nutrient sources. Liquid 2% malt shaking cultures produced the same amount of pigment in 5 weeks that previous testing produced in 2 months. Xylindein generation speed, purity, and conductive properties of produced pigment for (opto)electronics was then compared between two Chlorociboria species native to North America, Chlorociboria aeruginosa and Chlorocibori... [more]
Novel Hemocompatible Imine Compounds as Alternatives for Antimicrobial Therapy in Pharmaceutical Application
Mohammad A. Altamimi, Afzal Hussain, Sultan Alshehri, Syed Sarim Imam, Abdulmalik Alnami, Ahmed Bari
May 27, 2021 (v1)
Subject: Biosystems
Keywords: characterization, in vitro antimicrobial assay, in vitro hemolysis, local and systemic infection control, novel imine compounds
The aim of this study was to synthesize, characterize, and evaluate neoteric imine compounds for antimicrobial activity and hemocompatibility. Four compounds were synthesized using 3-thiophene carboxaldehyde, ethanol, amine, and acetic acid. The compounds were characterized using nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and powder X-ray diffraction (PXRD). A solubility study was conducted with various solvents and surfactants at 40 °C. An in vitro antimicrobial assay was performed against bacterial and fungal strains to determine the zone of inhibition and minimum inhibitory concentrations. Finally, an in vitro hemolysis study was conducted using rat erythrocytes. The structure of the compounds was confirmed by NMR, FTIR corroborated their functional group attributes, DSC determined their enthalpies of fusion and fusion temperatures, and PXRD confirmed their crystalline nature. These compound... [more]
Analysis of Dynamic Engaged Characteristics of Wet Clutch in Variable Speed Transmission of a Helicopter
Heyun Bao, Tongjing Xu, Guanghu Jin, Wei Huang
May 27, 2021 (v1)
Subject: Other
Keywords: characteristics of dynamic engagement, oil film thickness, spring preload, variable speed helicopter transmission, wet clutch
The working principle and motion process of an aviation wet clutch are analyzed. The initial velocity before the friction pair engaged is solved. The transient Reynolds equation is modified, and an oil film bearing capacity model and a micro-convex bearing capacity model are derived. The film thickness equation between N friction pairs and a pressure-plate is derived. A dynamic engaged model of springs, pistons, friction pairs, and pressure plates are established. The torque balance equation is established of two pairs of friction pairs. The friction torque, rate of change in the oil film, and law of relative change in speed are obtained. The results demonstrate that the spring preload and the viscosity of the lubricating oil have a significant influence on the engagement characteristics. Increasing the quality of the friction plate will reduce the time of engagement, whereas the quality of the friction plate has slight effect on the friction torque characteristics and oil film thickne... [more]
Functional Polymer Hybrid Nanocomposites Based on Polyolefins: A Review
Sandra Paszkiewicz, Krzysztof Pypeć, Izabela Irska, Elzbieta Piesowicz
May 27, 2021 (v1)
Subject: Materials
Keywords: functional properties, high-density polyethylene, hybrid nanocomposites, low-density polyethylene, polyolefins, polypropylene
For the last twenty years, polymer hybrid nanocomposites have enjoyed unflagging interest from numerous scientific groups and R&D departments, as they provide notable enhancement of properties, even at low nanofillers’ content. Their performance results from many factors, the most important of which is the uniform distribution in the entire volume of the matrix, that still is very challenging, but is the right choice of two types of nanoparticles that can lead to an increase of dispersion stability and even more uniform distribution of fillers. The incorporation of two types of nanofillers, especially when they differ in aspect ratio or chemical nature, allows to additively reduce the price of the final composite by replacing the more expensive filler with the cheaper one, or even synergistically improving the properties, e.g., mechanical, thermal, and barrier, etc., that can extend their usage in the industry. Despite numerous review papers on nanocomposites, there is no review on how... [more]
In Vitro Molecular Biology Studies of Spirooxindole Heterocyclic Hybrids
Dhaifallah M. Al-thamili, Abdulrahman I. Almansour, Natarajan Arumugam, Faruq Mohammad, Raju Suresh Kumar
May 27, 2021 (v1)
Subject: Biosystems
Keywords: anticancer activity, apoptosis, caspase-3 activity, controlled cell death, functionalized spiroheterocycles, ROS generation
 In the present report, we provide the results of the molecular biology studies of spiroheterocyclic hybrids, where the derivatives are found to possess potential anticancer activity towards cancer cells. A series of spiroxindole−pyrrolidine heterocyclic hybrids were evaluated for cell viability and proliferation against HepG2 cancer cells at concentrations in the range of 12.5−200 µg/mL over two different time periods of 24 and 48 h. In addition, the highly active compounds were also verified for their behavior towards noncancer cells (L929 cells), and it was found that the tested derivatives were not aggressive due to the observation of only limited cell loss, as compared to the cancer cells. Further analysis of the observed toxicity mechanism showed the apoptotic pathway was mediated by oxidative stress, with the involvement of caspases.
Effect of Strain Hardening Laws on Solution Behavior Near Frictional Interfaces in Metal Forming Processes: A Simple Analytical Example
Sergei Alexandrov, Elena Lyamina, Pierre-Yves Manach
May 27, 2021 (v1)
Subject: Other
Keywords: friction, metal forming processes, plasticity, singularity, work hardening
The main objective of the present paper is to compare, by means of a problem leading to a closed-form solution, the qualitative behavior of solutions based on three strain hardening laws: Swift’s law, Ludwik’s law, and Voce’s law. The boundary value problem involves the maximum friction law as one of the boundary conditions. Such features of the solutions as nonexistence and singularity are emphasized. An important feature of Swift’s and Ludwik’s laws is that the equivalent stress approaches infinity as the equivalent strain approaches infinity. On the contrary, Voce’s law involves saturation stress as one of the constitutive parameters. This qualitative difference in the equivalent stress behavior as the equivalent strain approaches infinity results in the qualitative difference in solutions’ behavior. In particular, Swift’s and Ludwik’s hardening laws are compatible with the regime of sticking independently of other conditions. In the case of Voce’s law, the solution under sticking c... [more]
NOx Emission Reduction by Advanced Reburning in Grate-Rotary Kiln for the Iron Ore Pelletizing Production
Bing Hu, Peiwei Hu, Biao Lu, Zhicheng Xie, Liu Liu, Gangli Cheng, Jiaoyang Wei
May 27, 2021 (v1)
Keywords: advanced reburning, denitrification, grate-rotary kiln, NOx reduction
The NOx reduction in the iron ore pelletizing process becomes an important environmental concern owing to its role in the formation of photochemical smog and acid rain. Thus, it is essential to develop new technologies for reducing NOx emissions in order to contribute to the cleaner production of pellets. In this paper, NOx reduction by advanced reburning ingrate-rotary kiln for oxidized pellet production was performed on a laboratory-scale gas kiln. Temperature and NH3/NOx molar ratio (NSR) were the key factors affecting the reduction of NOx. A better denitrification effect can be obtained on flus gas with higher initial NOx concentration, at temperature = 900 °C, NSR = 1.2, and reaction time exceeds one second. NOx reduction rate had reached 55−65% when the initial NOx concentration was above 400 ppm, and exceeds 70% when the initial NOx concentration was around 680 ppm. Urea solution has the best denitrification effect compared with NH3·H2O and NH4HCO3 solution. As for additives, th... [more]
A Novel Approach Using Conventional Methodologies to Scale up BNC Production Using Komagataeibacter medellinensis and Rotten Banana Waste as Alternative
Carlos Molina-Ramírez, Juan Álvarez, Robin Zuluaga, Cristina Castro, Piedad Gañán
May 27, 2021 (v1)
Keywords: agro-food waste, BNC production optimization, BNC scale-up strategy, rotten banana
Currently, cellulose nanostructures are among the most promising structures, and extensive work in materials and biotechnology industries is aimed at identifying an efficient process of production. Even when production at the laboratory scale is successful, crucial aspects of increased commercial applications for cellulose nanostructures are linked to large-scale production. Large-scale production requires a balance between the cost of the culture medium and product value. Therefore, in this work, for the optimization and scaling up of bacterial nanocellulose, a culture medium consisting of rotten banana unsuitable for human consumption was used for the first time as an inexpensive feedstock. Initially, the bacterial nanocellulose (BNC) culture medium conditions were optimized, and it was established that a glucose concentration of 26.4 g/L and a V/A ratio of 2.2 cm were the optimal conditions for production reaching a BNC yield of 5 g/L, which was 42.4% higher than the best result ini... [more]
Scutellaria baicalensis Flavones as Potent Drugs against Acute Respiratory Injury during SARS-CoV-2 Infection: Structural Biology Approaches
Ana-Maria Udrea, Maria Mernea, Cătălin Buiu, Speranța Avram
May 27, 2021 (v1)
Subject: Biosystems
Keywords: antiviral, bioinformatics, flavonoids, infections, pharmacodynamic, pharmacokinetics, SARS-CoV-2, Scutellaria baicalensis
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can result in severe damage to the respiratory system. With no specific treatment to date, it is crucial to identify potent inhibitors of SARS-CoV-2 Chymotrypsin-like protease (3CLpro) that could also modulate the enzymes involved in the respiratory damage that accompanies SARS-CoV-2 infection. Here, flavones isolated from Scutellaria baicalensis (baicalein, baicalin, wogonin, norwogonin, and oroxylin A) were studied as possible compounds in the treatment of SARS-CoV-2 and SARS-CoV-2-induced acute lung injuries. We used structural bioinformatics and cheminformatics to (i) identify the critical molecular features of flavones for their binding activity at human and SARS-CoV-2 enzymes; (ii) predict their drug-likeness and lead-likeness features; (iii) calculate their pharmacokinetic profile, with an emphasis on toxicology; (iv) predict their pharmacodynamic profiles, with the identification of their human body targets... [more]
A Methodology to Estimate the Sorption Parameters from Batch and Column Tests: The Case Study of Methylene Blue Sorption onto Banana Peels
Anastasia Stavrinou, Christos A. Aggelopoulos, Christos D. Tsakiroglou
May 27, 2021 (v1)
Keywords: Adsorption, banana peels, breakthrough curve, methylene blue, sorption models, thermodynamics
In the present work, a methodology is presented where batch and fixed-bed column tests of dye sorption onto granular biosorbents are analyzed with properly selected models to estimate the parameters required for the rational design of pilot-scale units. The sorption of methylene blue (MB) onto banana peels (BP) was investigated as a case study. To identify the mechanisms of MB sorption onto BP, the pore structure and surface of BP were characterized with mercury intrusion porosimetry (MIP), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Batch tests were performed over the temperature range of 15−45 °C, and three models (Langmuir, Freundlich, Langmuir−Freundlich) were fitted to equilibrium and kinetic data for (i) estimating thermodynamic/kinetic parameters and (ii) choosing the model with the best goodness-of-fit. Sorption tests on fixed-bed columns were combined with a one-dimensional macroscopic convection/dispersion/sorption model to estimate... [more]
Alcohol Dehydration by Extractive Distillation with Use of Aminoethers of Boric Acid
Alexander V. Klinov, Alexander V. Malygin, Alina R. Khairullina, Sergey E. Dulmaev, Ilsiya M. Davletbaeva
May 27, 2021 (v1)
Keywords: aqueous solution, Extraction, UNIFAC model, vapor–liquid equilibrium
Aminoethers of boric acid (AEBA) were studied as potential extractants for the separation of aqueous−alcoholic azeotropic mixtures by extractive distillation. The conditions of vapor−liquid equilibrium in aqueous solutions of ethanol and isopropanol in the presence of AEBA were studied. The division of AEBA molecules into group components was proposed, and previously unknown geometric parameters of the boron group and the energetic pair parameters of the boron group with the alkane group, ether group, amine-3d group, and alcohol group were determined within the framework of the Universal Functional Group Activity Coefficient (UNIFAC) model. The modeling of the extractive rectification process of an ethanol−water mixture with AEBA as extractant has been carried out. The dependences of the cost function on the extractant flow rate, the residual water content in it and the number of theoretical trays were obtained. A technological scheme for ethanol dehydration has been proposed, and its... [more]
Collaborative Control Applied to BSM1 for Wastewater Treatment Plants
Keidy Morales-Rodelo, Mario Francisco, Hernan Alvarez, Pastora Vega, Silvana Revollar
May 27, 2021 (v1)
Keywords: collaborative control, hierarchical control, mass transfer model, Model Predictive Control, wastewater treatment plant
This paper describes a design procedure for a collaborative control structure in Plant Wide Control (PWC), taking into account the existing controllable parameters as a novelty in the procedure. The collaborative control structure includes two layers, supervisory and regulatory, which are determined according to the dynamics hierarchy obtained by means of the Hankel matrix. The supervisory layer is determined by the main dynamics of the process and the regulatory layer comprises the secondary dynamics and controllable parameters. The methodology proposed is applied to a wastewater treatment plant, particularly to the Benchmark Simulation Model No 1 (BSM1) for the activated sludge process, comparing the results with the use of a Model Predictive Controller in the supervisory layer. For determining controllable parameters in the BSM1 control, a new specific oxygen mass transfer model in the biological reactor has been developed, separating the kLa volumetric mass transfer coefficient int... [more]
Real-Time 3D Printing Remote Defect Detection (Stringing) with Computer Vision and Artificial Intelligence
Konstantinos Paraskevoudis, Panagiotis Karayannis, Elias P. Koumoulos
May 27, 2021 (v1)
Keywords: 3D printing, additive manufacturing, Artificial Intelligence, computer vision, neural network
This work describes a novel methodology for the quality assessment of a Fused Filament Fabrication (FFF) 3D printing object during the printing process through AI-based Computer Vision. Specifically, Neural Networks are developed for identifying 3D printing defects during the printing process by analyzing video captured from the process. Defects are likely to occur in 3D printed objects during the printing process, with one of them being stringing; they are mostly correlated to one of the printing parameters or the object’s geometries. The defect stringing can be on a large scale and is usually located in visible parts of the object by a capturing camera. In this case, an AI model (Deep Convolutional Neural Network) was trained on images where the stringing issue is clearly displayed and deployed in a live environment to make detections and predictions on a video camera feed. In this work, we present a methodology for developing and deploying deep neural networks for the recognition of... [more]
Challenges and Opportunities on Nonlinear State Estimation of Chemical and Biochemical Processes
Ronald Alexander, Gilson Campani, San Dinh, Fernando V. Lima
May 27, 2021 (v1)
Keywords: extended Kalman filter, moving horizon estimation, nonlinear system, state estimation
This paper provides an overview of nonlinear state estimation techniques along with a discussion on the challenges and opportunities for future work in the field. Emphasis is given on Bayesian methods such as moving horizon estimation (MHE) and extended Kalman filter (EKF). A discussion on Bayesian, deterministic, and hybrid methods is provided and examples of each of these methods are listed. An approach for nonlinear state estimation design is included to guide the selection of the nonlinear estimator by the user/practitioner. Some of the current challenges in the field are discussed involving covariance estimation, uncertainty quantification, time-scale multiplicity, bioprocess monitoring, and online implementation. A case study in which MHE and EKF are applied to a batch reactor system is addressed to highlight the challenges of these technologies in terms of performance and computational time. This case study is followed by some possible opportunities for state estimation in the f... [more]
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