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Records Added in October 2020
Records added in October 2020
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Showing records 40 to 64 of 64. [First] Page: 1 2 3 Last
Volatile Esters and Fusel Alcohol Concentrations in Beer Optimized by Modulation of Main Fermentation Parameters in an Industrial Plant
Krzysztof Kucharczyk, Krzysztof Żyła, Tadeusz Tuszyński
October 26, 2020 (v1)
Keywords: beer brewing, industrial plant, manufacturing scale, process optimization, response surface methodology, sensory quality, volatile compounds
Contents of selected volatile esters and fusel alcohols and their relation to the sensory quality of a bottom-fermented lager beer fermented under high-gravity conditions (15.5 °P) were analyzed using response surface methodology (RSM, Box−Behnken design). The influence of various pitching rates (6−10 mln cells/mL), aeration levels (8−12 mgO2/mL), times (4.5−13.5 h) of filling CCTs (cylindroconical fermentation tanks; 3850 hL), and fermentation temperatures (8.5−11.5 °C) on the contents of selected esters, as well as on concentrations of amyl alcohols and on the sum of higher alcohols in beer, was determined in a commercial brewery fermentation plant. Beers produced throughout the experiments met or exceeded all criteria established for a commercial, marketed beer. Statistical analyses of the results revealed that within the studied ranges of process parameters, models with diversified significance described the concentrations of volatiles in beer. The multiple response optimization pr... [more]
Cell Factories for Industrial Production Processes: Current Issues and Emerging Solutions
Clara Navarrete, Irene Hjorth Jacobsen, José Luis Martínez, Alessandra Procentese
October 26, 2020 (v1)
Subject: Biosystems
Keywords: biomass pretreatment, bioreactor configuration, cell factory, Debaryomyces hansenii, lignocellulosic biomass, lignocellulosic inhibitors, Trichosporon oleaginosus, Ustilago cynodontis, Yarrowia lipolytica
Despite all the progresses made by metabolic engineering, still only a few biotechnological processes are running at an industrial level. In order to boost the biotechnological sector, integration strategies as well as long-term views are needed. The aim of the present review is to identify the main drawbacks in biotechnological processes, and to propose possible solutions to overcome the issues in question. Novel cell factories and bioreactor design are discussed as possible solutions. In particular, the following microorganisms: Yarrowia lipolytica, Trichosporon oleaginosus, Ustilago cynodontis, Debaryomyces hansenii along with sequential bioreactor configurations are presented as possible cell factories and bioreactor design solutions, respectively.
Hair Growth Effect of Emulsion Extracted Brevilin A, a JAK3 Inhibitor, from Centipeda minima
Byoung Ha Kim, Won-Yung Lee, Tuy An Trinh, Jae Sung Pyo, Sooyeun Lee, Chang-Eop Kim, Dong Hwan Lee, Eun-Seok Park, Ki Sung Kang
October 26, 2020 (v1)
Subject: Biosystems
Keywords: brevilin A, Centipeda minima, hair growth, Janus kinase-signal transducer and activator of transcription signaling pathway, network pharmacology
Janus kinase 3 (JAK3) inhibitors have been used effectively in the treatment of several cases of alopecia universalis and its variants. Our study aims to evaluate whether the emulsion extract of brevilin A from Centipeda minima (CMX) stimulates hair regrowth in a clinical trial, as a JAK3 inhibitor, combined with network pharmacology-based analysis. CMX showed potent inhibition of JAK3 in a concentration-dependent manner. Significant differences in total hair count, terminal hair count, and anagen hair count from the baseline to 24 weeks were observed between the placebo and CMX subjects. The gene set enrichment analysis showed that the targets of CMX are mainly associated with the JAK-STAT signaling pathway, cytokine−cytokine receptor interactions, and the MAPK signaling pathway. This study suggests that the medicinal herbal extract CMX is useful in the treatment of mild to moderate vertex balding that contribute to the visible improvements in hair growth observed in treated patients.
Simulations of candidate vaccine injections: A talk for chemical process systems engineers
Thomas A Adams II, David A Christian, Mosana Abraha, Christopher A Hunter, Ross M Kedl
October 14, 2020 (v2)
Subject: Biosystems
Keywords: COVID-19, immune process systems, immune system model, stochastic finite state machine, vaccine development
This work highlights the role of process system engineering (PSE) principles (especially simulation and optimization) in the development of a COVID-19 vaccine and other kinds of vaccines. As a result of a unique multi-national collaboration of PSE-minded chemical engineers, immunologists, and pathologists, we have created computer models of how the human body's immune system responds to vaccine injections of various kinds. The STochastic Omentum REsponse model (STORE) is stochastic, agent-based, and dynamic, and tracks how T-cells and antigen presenting cells interact, change, divide, and respond after an immune event such as a vaccine injection or an infection. Using model parameters related to dosage, injection schedule, genetic traits of the patient, and various vaccine or immune system properties, the STORE model can be used to predict how the human body responds in the days and weeks after a vaccine injection.

The STORE model consists of a collection of small, agent-based mode... [more]
A Detailed Mathematical Model for Evaluation of Solid Oxide Fuel Cells Performance Degradation
Mina Naeini, James S. Cotton, Thomas A. Adams II
October 14, 2020 (v1)
Keywords: Degradation rate, Long-term performance, Optimal operation, SOFCs
The performance of Solid Oxide Fuel Cells (SOFCs) degrades due to various reactions. Lack of a general model based on these reactions that predicts SOFCs long-time performance with few assumptions, limits commercialization of SOFCs. In this work, a detailed mathematical model is constructed to evaluate SOFCs long-term performance with regard to operating conditions. Most of the reactions that greatly deteriorates SOFCs components; such as Ni coarsening and oxidation, anode pore diameter changes, deterioration of anode conductivity and electrolyte conductivity, and sulfur poisoning are considered in this model to ensure that it yields reliable and precise results. A broad literature survey indicated that previously developed models only account for a part of these reactions and hence they do not provide accurate results. Rest of the models, on the other hand, are regression models that have been fitted to experimental data and thus are valid in a limited range of operating parameters.... [more]
Carbon Sequestration in Support of the “4 per 1000” Initiative Using Compost and Stable Biochar from Hazelnut Shells and Sunflower Husks
Klaus Mikula, Gerhard Soja, Cristina Segura, Alex Berg, Christoph Pfeifer
October 6, 2020 (v1)
Keywords: fixed bed reactor, pyrolysis, rotary kiln, screw reactor, soil organic carbon (SOC)
The achievement of carbon neutrality till 2050 will require the deployment of negative carbon emission technologies like the production and soil incorporation of biochar, produced from pyrolyzed plant-based residues. The carbon sequestration potential of biochar (BC) from hazelnut (Corylus avellana L.) shells (HNS) and sunflower (Helianthus annuus L.) husks (SFH) was evaluated when the biomass was carbonized in a fixed bed reactor, in a rotary kiln and in a screw reactor. In all tested reactors, higher temperatures (>500 °C) and longer retention times increased the C concentration and stability of the biochar, with negligible effects of the reactor type and feedstock. A national case study was developed for Austria concerning the potential use of SFH- and HNS-BC in combination with compost for reaching the “4 per mille” objective. An annual soil organic carbon increase of 2.5 Mt C would be needed, requiring amendment rates of 2.2 Mt C a−1 for all annual crop areas and 0.3 Mt C a−1 for... [more]
Modification of Conventional Sugar Juice Evaporation Process for Increasing Energy Efficiency and Decreasing Sucrose Inversion Loss
Somchart Chantasiriwan
October 6, 2020 (v1)
Keywords: Energy Efficiency, heat exchanger, inversion loss, mass transfer, mathematical model, process design
The evaporation process, boiler, and turbine are the main components of the cogeneration system of the sugar factory. In the conventional process, the evaporator requires extracted steam from the turbine, and bled vapor from the evaporator is supplied to the juice heater and the pan stage. The evaporation process may be modified by using extracted steam for the heating duty in the pan stage. This paper is aimed at the investigation of the effects of this process modification. Mathematical models of the conventional and modified processes were developed for this purpose. It was found that, under the conditions that the total evaporator area is 13,000 m2, and the inlet juice flow rate is 125 kg/s, the optimum modified evaporation process requires extracted steam at a pressure of 157.0 kPa. Under the condition that the fuel consumption rate is 21 kg/s, the cogeneration system that uses the optimum modified evaporation process yields 2.3% more power output than the cogeneration system that... [more]
The Development of a Waste Tyre Pyrolysis Production Plant Business Model for the Gauteng Region, South Africa
Nhlanhla Nkosi, Edison Muzenda, Tirivaviri A. Mamvura, Mohamed Belaid, Bilal Patel
October 6, 2020 (v1)
Keywords: batch pyrolysis, business model, South Africa, waste tyres
Some of today’s modern life challenges include addressing the increased waste generation and energy deficiencies. Waste tyres have been identified as one of the key environmental concerns due to their non-biodegradable nature and bulk storage space demand. Pyrolysis is a thermochemical process with the potential to address the growing waste tyre problem, energy deficits, and material recovery by converting waste tyres to pyrolysis oil that can be used as a fuel. This study seeks to critically evaluate the feasibility of constructing and operating a waste tyre processing facility and then subsequently marketing and selling the pyrolysis secondary end products by developing a financial business model. The model encompasses costing, procurement, installation, commissioning, and operating a batch pyrolysis plant in Gauteng, South Africa. To achieve the study objectives, an order of magnitude costing method was used for model construction. The results showed the feasibility and sustainabili... [more]
Modelling of a Single Passage Air PV/T Solar Collector: Experimental and Simulation Design
Noran Nur Wahida Khalili, Mahmod Othman, Mohd Nazari Abu Bakar, Lazim Abdullah
October 6, 2020 (v1)
Keywords: 1D steady-state, photovoltaic/thermal, single pass, solar collector
The hybrid photovoltaic/thermal solar collector has attracted research attention for more than five decades. Its capability to produce thermal energy simultaneously with electrical energy is considered attractive since it provides higher total efficiency than stand-alone photovoltaic or thermal systems separately. This paper describes theoretical and experimental studies of a finned single pass air-type photovoltaic/thermal (PV/T) solar collector. The performance of the system is calculated based on one dimensional (1D) steady-state analysis using one dimensional energy balance equations, where simulation was carried out using MATLAB. Experiments were carried out to observe the performance of the solar collector under changes in air mass flow rate. Experimental values on photovoltaic panel temperature and air temperature on both air inlet and outlet, together with the ambient temperature and solar radiation were measured. The simulation results were validated against the results obtain... [more]
Microemulsion Rheological Analysis of Alkaline, Surfactant, and Polymer in Oil-Water Interface
Mohd Sofi Numin, Khairulazhar Jumbri, Anita Ramli, Noorazlenawati Borhan
October 6, 2020 (v1)
Subject: Other
Keywords: alkali, chemical enhanced oil recovery (cEOR), emulsion rheology test, emulsion tendency test, polymer, surfactant
Injection of alkaline (A), polymer (P), and surfactant (S) chemicals in enhanced oil recovery (cEOR) processes increases output by changing the properties of the injected fluid. In this work, micellar fluid interactions were studied via microemulsion rheological analysis. Crude oil and stimulated brine with ASP or SP was used for bottle testing. The results revealed that no microemulsion was produced when ASP (Alkaline, Surfactant, and Polymer) or SP (Surfactant and Polymer) was left out during the bottle testing phase. The addition of ASP and SP led to the formation of microemulsions—up to 29% for 50% water cut (WC) ASP, and 36% for 40% WC SP. This shows that the addition of ASP and SP can be applied to flooding applications. The results of the rheological analysis show that the microemulsions behaved as a shear-thinning micellar fluid by decreasing viscosity with increase in shear rate. As per the power-law equation, the ASP micellar fluid viscoelastic behavior shows better shear-thi... [more]
Effects of Different Drying Methods and Temperature on the Drying Behavior and Quality Attributes of Cherry Laurel Fruit
Fatma Turkmen, Salih Karasu, Ayse Karadag
October 6, 2020 (v1)
Keywords: microstructure, rehydration, SEM, ultrasound-assisted vacuum drying
This study aimed to investigate the effect of different drying methods and drying temperature on the drying kinetics, total bioactive compounds, phenolic profile, microstructural properties, rehydration kinetics, and color change of cherry laurel fruit. For this aim, hot air drying (HAD), ultrasound-assisted vacuum drying (USV), and freeze-drying (FD) were conducted on drying of cherry laurel. HAD and USV were conducted at 50, 60, and 70 °C. Drying times of the samples were 1980, 1220, and 770 min for HAD at 50, 60 and 70 °C, and 950, 615, and 445 min at 50, 60, and 70 °C, respectively, for USV. The total bioactive compound was significantly affected by both drying methods and temperature (p < 0.05). FD exhibited the highest total phenolic (TPC), total flavonoid (TFC), total anthocyanin (TAC), and antioxidant capacity value USV showed a higher amount of bioactive compounds than those of HAD at the same drying temperature. The content of total bioactive compounds significantly increa... [more]
Dynamic Characteristics and Wall Effects of Bubble Bursting in Gas-Liquid-Solid Three-Phase Particle Flow
Jianfei Lu, Tong Wang, Lin Li, Zichao Yin, Ronghui Wang, Xinghua Fan, Dapeng Tan
October 6, 2020 (v1)
Keywords: bubble burst, gas-liquid-solid three-phase particle flow, micro-jet, PLIC-VOF, wall effect
The bubble bursting process existing in the particle flow is a complex gas-liquid-solid three-phase coupling dynamic problem. The bubble bursting mechanism, including dynamic characteristics and wall effects, is not clear. To address the above matters, we present a modeling method for the piecewise linear interface calculation-volume of fluid (PLIC-VOF) based bubble burst. The bubble bursting process near or on the wall is analyzed to reveal the dynamic characteristics of bubble bursting and obtain the effect of a bubble bursting on the surrounding flow field. Then a particle image velocimetry (PIV) based self-developed experimental observation platform is established, and the effectiveness of the proposed method is verified. Research results indicate that, in the high-speed turbulent environment, a large pressure difference existed in the bubble tail, which induces the bubble burst to occur; the distance between the wall and the bubble decreases; the higher the flow velocity is, the l... [more]
Hydrothermal−Microwave Processing for Starch Extraction from Mexican Avocado Seeds: Operational Conditions and Characterization
Rafael G. Araújo, Rosa M. Rodríguez-Jasso, Héctor A. Ruiz, Mayela Govea-Salas, Walfred Rosas-Flores, Miguel Angel Aguilar-González, Manuela E. Pintado, Claudia Lopez-Badillo, Cynthia Luevanos, Cristobal Noe Aguilar
October 6, 2020 (v1)
Keywords: avocado seeds, microwave-assisted extraction, starch source
Avocado seeds are an agroindustrial residue widely produced in Mexico that are causing various environmental problems due to their accumulation. The evaluation of avocado residues to recover biopolymers by microwave-assisted extraction (MAE) and the characterization of avocado starch properties were studied in the present work. A central-composite design was used to optimize the MAE process. Moreover, a comparison was performed between MAE non-isothermal mode (NO−ISO) and conventional extraction. Starch optimization by MAE was obtained at 161.09 °C for 56.23 min with an extraction yield of 49.52% ± 0.69%, while with NO−ISO at 161 °C was obtained 45.75% ± 2.18%. Conventional extraction was 39.04% ± 2.22%. Compared with conventional starch, MAE starch showed similar proprieties and molecular spectra. In contrast, MAE starch showed high solubility, low water absorption capacity, a non-granular structure with small particle size (<2 µm) and polydispersity of fragments at different sizes... [more]
A Comprehensive Energy and Exergoeconomic Analysis of a Novel Transcritical Refrigeration Cycle
Bourhan Tashtoush, Karima Megdouli, Mouna Elakhdar, Ezzedine Nehdi, Lakdar Kairouani
October 6, 2020 (v1)
Keywords: Carbon Dioxide, economic and exergy analysis, ejector refrigeration cycle, refrigeration, transcritical cycle, waste heat
A comprehensive energy and exergoeconomic analysis of a novel transcritical refrigeration cycle (NTRC) is presented. A second ejector is introduced into the conventional refrigeration system for the utilization of the gas-cooler waste heat. The thermodynamic properties of the working fluid are estimated by the database of REFPROP 9, and a FORTRAN program is used to solve the system governing equations. Exergy, energy, and exergoeconomic analyses of the two cycles are carried out to predict the exergetic destruction rate and efficiency of the systems. The optimum gas cooler working pressure will be determined for both cycles. A comprehensive comparison is made between the obtained results of the conventional and the new cycles. An enhancement of approximately 30% in the coefficient of performance (COP) of the new cycle was found in comparison to the value of the conventional cycle. In addition, the results of the analysis indicated a reduction in the overall exergy destruction rate and... [more]
Phytochemical Composition and Enzyme Inhibition Studies of Buxus papillosa C.K. Schneid
Hammad Saleem, Thet Thet Htar, Rakesh Naidu, Gokhan Zengin, Marcello Locatelli, Angela Tartaglia, Syafiq Asnawi Zainal Abidin, Nafees Ahemad
October 6, 2020 (v1)
Keywords: amylase, antioxidant, Buxus papillosa, lipoxygenase, phenolic compounds, tyrosinase
The current research work is an endeavor to study the chemical profiling and enzyme-inhibition potential of different polarity solvent (n-hexane, dichloromethane—DCM and methanol—MeOH) extracts from the aerial and stem parts of Buxus papillosa C.K. Schneid. All the extracts were analyzed for HPLC-PDA phenolic quantification, while both (aerial and stem) DCM extracts were studied for UHPLC-MS phytochemical composition. The inhibitory activity against the clinically important enzymes having crucial role in different pathologies like skin diseases (tyrosinase), inflammatory problems (lipoxygenase—LOX) and diabetes mellitus (α-amylase) were studied using standard in vitro bioassays. The DCM extracts upon UHPLC-MS analysis conducted in both negative and positive ionization modes has led to the tentative identification of 52 important secondary metabolites. Most of these belonged to the alkaloid, flavonoid, phenolic and triterpenoid classes. The HPLC-PDA polyphenolic quantification identifie... [more]
Thermal Performance Enhancement in Flat Plate Solar Collector Solar Water Heater: A Review
Nurril Ikmal Shamsul Azha, Hilmi Hussin, Mohammad Shakir Nasif, Tanweer Hussain
October 6, 2020 (v1)
Subject: Other
Keywords: flat-plate collector, heat-transfer enhancement using vibration, infrasound, solar water heater, thermal performance
Various studies to improve the thermal performance of flat plate solar collector (FPSC) solar water heater have been conducted, and more are currently in progress. This study aims to review existing methods on thermal performance enhancement for FPSC and discuss on heat-transfer enhancement using vibration and its potential application for FPSC. Ten methods for improving thermal performance are identified, which include applications of nanofluids, absorber coatings, phase change materials (PCM), thermal performance enhancers, FPSC design modifications, polymer materials, heat loss reduction, mini and micro channel and heat-transfer enhancement using vibration. An examination of heat-transfer enhancement using vibration in low frequency ranges for an evacuated-tube solar collector (ETSC) solar water heater system showed that it can potentially achieve heat-transfer enhancement of up to 78%. Nevertheless, there is still a lack of research on the applications of heat-transfer enhancement... [more]
Geological Risk Calculation through Probability of Success (PoS), Applied to Radioactive Waste Disposal in Deep Wells: A Conceptual Study in the Pre-Neogene Basement in the Northern Croatia
Tomislav Malvić, Maria Alzira Pimenta Dinis, Josipa Velić, Jasenka Sremac, Josip Ivšinović, Marija Bošnjak, Uroš Barudžija, Želimir Veinović, Hélder Fernando Pedrosa e Sousa
October 6, 2020 (v1)
Keywords: geological risk, northern Croatia, pre-Neogene basement, probability of success (PoS), radioactive waste disposal
The basic principles of geological risk calculation through probability of success (PoS) are mostly applied to numerical estimation of additional hydrocarbon existence in proven reservoirs or potential hydrocarbon discoveries in selected geological regional subsurface volumes. It can be adapted and validated for a comprehensive input dataset collected in the selected petroleum province, by dividing up geological events into several probability categories and classes. Such methodology has been widely developed in the last decades in the Croatian subsurface—mostly in the Croatian Pannonian Basin System (CPBS). Through the adaptation of geological categories, it was also applied in hybrid, i.e., stochastic, models developed in the CPBS (Drava Depression), mostly for inclusion of porosity values. As the robustness of this methodology is very high, it was also modified to estimate the influence of water-flooding in increasing oil recovery in some proven Neogene sandstone reservoirs in the C... [more]
Thermal and Fluid Dynamic Performance Comparison of Three Nanofluids in Microchannels Using Analytical and Computational Models
Dustin R. Ray, Roy Strandberg, Debendra K. Das
October 6, 2020 (v1)
Subject: Materials
Keywords: Computational Fluid Dynamics, entropy, fluent, heat transfer, microchannel, nanofluids
The fluid dynamic and thermal performance of three nanofluids containing aluminum oxide, copper oxide, and silicon dioxide nanoparticles dispersed in 60:40 ethylene glycol and water base fluid as a coolant in a microchannel heatsink are compared here by two methods. The first is a simple analytical analysis, which is acceptable for very low nanoparticle volumetric concentration (1−2%). The second method is a rigorous three-dimensional finite volume conjugate heat transfer and fluid dynamic model based upon a constant heat flux boundary condition, which is applicable for cooling electronic chips. The fluids’ thermophysical properties employed in the modeling are based on empirically derived, temperature dependent correlations from the literature. The analytical and computational results for pressure drop and Nusselt number were in good agreement with the nanofluids showing a maximum difference of 4.1% and 2.9%, respectively. Computations cover the practical range of Reynolds number from... [more]
Simultaneous Electrochemical Generation of Ferrate and Oxygen Radicals to Blue BR Dye Degradation
Mauricio Chiliquinga, Patricio J. Espinoza-Montero, Oscar Rodríguez, Alain Picos, Erick R. Bandala, S. Gutiérrez-Granados, Juan M. Peralta-Hernández
October 6, 2020 (v1)
Keywords: advace oxitadion processes (AOP), BBR dye, electro-oxidation, ferrate ion
In this study, electro-oxidation (EOx) and in situ generation of ferrate ions [Fe(VI)] were tested to treat water contaminated with Blue BR dye (BBR) using a boron-doped diamond (BDD) anode. Two electrolytic media (0.1 M HClO4 and 0.05 M Na2SO4) were evaluated for the BDD, which simultaneously produced oxygen radicals (•OH) and [Fe(VI)]. The generation of [Fe(VI)] was characterized by cyclic voltammetry (CV) and the effect of different current intensity values (e.g., 7 mA cm−2, 15 mA cm−2, and 30 mA cm−2) was assessed during BBR degradation tests. The discoloration of BBR was followed by UV-Vis spectrophotometry. When the EOx process was used alone, only 78% BBR discoloration was achieved. The best electrochemical discoloration conditions were found using 0.05 M Na2SO4 and 30 mA cm−2. Using these conditions, overall BBR discoloration values up to 98%, 95%, and 87% with 12 mM, 6 mM, and 1 mM of FeSO4, respectively, were achieved. In the case of chemical oxygen demand (COD) reduction, th... [more]
Model-Based Process Optimization for the Production of Macrolactin D by Paenibacillus polymyxa
Dominik Krämer, Terrance Wilms, Rudibert King
October 6, 2020 (v1)
Keywords: Fermentation, multi-model approach, NIR spectroscopy, nonlinear state estimation, online optimization
In this study, we show the successful application of different model-based approaches for the maximizing of macrolactin D production by Paenibacillus polymyxa. After four initial cultivations, a family of nonlinear dynamic biological models was determined automatically and ranked by their respective Akaike Information Criterion (AIC). The best models were then used in a multi-model setup for robust product maximization. The experimental validation shows the highest product yield attained compared with the identification runs so far. In subsequent fermentations, the online measurements of CO2 concentration, base consumption, and near-infrared spectroscopy (NIR) were used for model improvement. After model extension using expert knowledge, a single superior model could be identified. Model-based state estimation with a sigma-point Kalman filter (SPKF) was based on online measurement data, and this improved model enabled nonlinear real-time product maximization. The optimization increased... [more]
Product Quality Detection through Manufacturing Process Based on Sequential Patterns Considering Deep Semantic Learning and Process Rules
Liguo Yao, Haisong Huang, Shih-Huan Chen
October 6, 2020 (v1)
Keywords: deep semantic learning, frequent pattern mining, manufacturing process diagnostics, manufacturing process rule, product quality detection
Companies accumulate a large amount of production process data during product manufacturing. Sequence data from the mining production process can enable a company to evaluate the manufacturing process, to find the key factors affecting product quality, and to improve product quality. However, the production process mainly exists in the form of text. To solve this problem, we propose a novel frequent pattern mining algorithm (EABMC) based on the text context semantics and rules of the manufacturing process to remove redundant sequences and to obtain good mining results. In this algorithm, first, we use embeddings from language models (ELMo ) to improve the process of text similarity matching and to classify similar semantic processes into one class. Then, the manufacturing process unit (MPU) is proposed by extracting the characteristics of manufacturing process data according to the constraints of the manufacturing process and other conditions. The above two steps cause the complex manu... [more]
Physical and Mathematical Modelling of Mass Transfer in Ladles due to Bottom Gas Stirring: A Review
Alberto N. Conejo
October 6, 2020 (v1)
Keywords: kinetic models, mass transfer coefficient, mathematical modeling, mixing time, physical modeling
Steelmaking involves high-temperature processing. At high temperatures mass transport is usually the rate limiting step. In steelmaking there are several mass transport phenomena occurring simultaneously such as melting and dissolution of additions, decarburization, refining (De-P and De-S), etc. In ladle metallurgy, refining is one of the most important operations. To improve the rate of mass transfer bottom gas injection is applied. In the past, most relationships between the mass transfer coefficient (mtc) and gas injection have been associated with stirring energy as the dominant variable. The current review analyzes a broad range of physical and mathematical modeling investigations to expose that a large number of variables contribute to define the final value of the mtc. Since bottom gas injection attempts to improve mixing phenomena in the whole slag/steel system, our current knowledge shows limitations to improve mixing conditions in both phases simultaneously. Nevertheless, so... [more]
Modelling Acetification with Artificial Neural Networks and Comparison with Alternative Procedures
Jorge E. Jiménez-Hornero, Inés María Santos-Dueñas, Isidoro García-García
October 6, 2020 (v1)
Keywords: acetification, artificial neural networks, bioreactor systems, Modelling, multilayer perceptron, vinegar
Modelling techniques allow certain processes to be characterized and optimized without the need for experimentation. One of the crucial steps in vinegar production is the biotransformation of ethanol into acetic acid by acetic bacteria. This step has been extensively studied by using two predictive models: first-principles models and black-box models. The fact that first-principles models are less accurate than black-box models under extreme bacterial growth conditions suggests that the kinetic equations used by the former, and hence their goodness of fit, can be further improved. By contrast, black-box models predict acetic acid production accurately enough under virtually any operating conditions. In this work, we trained black-box models based on Artificial Neural Networks (ANNs) of the multilayer perceptron (MLP) type and containing a single hidden layer to model acetification. The small number of data typically available for a bioprocess makes it rather difficult to identify the m... [more]
A Non-Delay Error Compensation Method for Dual-Driving Gantry-Type Machine Tool
Qi Liu, Hong Lu, Xinbao Zhang, Yu Qiao, Qian Cheng, Yongquan Zhang, Yongjing Wang
October 6, 2020 (v1)
Keywords: drive at the center of gravity (DCG), dual-driving system, error prediction, machine tool accuracy, non-delay error compensation
The drive at the center of gravity (DCG) principle has been adopted in computer numerical control (CNC) machines and industrial robots that require heavy-duty and quick feeds. Using this principle requires accurate corrections of positioning errors. Conventional error compensation methods may cause vibrations and unstable control performances due to the delay between compensation and motor motion. This paper proposes a new method to reduce the positioning errors of the dual-driving gantry-type machine tool (DDGTMT), namely, a typical DCG-principle-based machine tool. An error prediction method is proposed to characterize errors online. An algorithm is proposed to quickly and accurately compensate the errors of the DDGTMT. Experiment results verify that the non-delay error compensation method proposed in this paper can effectively improve the accuracy of the DDGTMT.
Environmental Remediation of Antineoplastic Drugs: Present Status, Challenges, and Future Directions
Abhilash Kumar Tripathi, Aditi David, Tanvi Govil, Shailabh Rauniyar, Navanietha Krishnaraj Rathinam, Kian Mau Goh, Rajesh Kumar Sani
October 6, 2020 (v1)
Subject: Biosystems
Keywords: antineoplastic drug, biodegradation, environment, remediation, toxicity
The global burden of cancer is on the rise, and as a result, the number of therapeutics administered for chemotherapy is increasing. The occupational exposure, recalcitrant nature and ecotoxicological toxicity of these therapeutics, referred to as antineoplastic (ANP) drugs, have raised concerns about their safe remediation. This review provides an overview of the environmental source of ANPs agents, with emphasis on the currently used remediation approaches. Outpatient excreta, hospital effluents, and waste from pharmaceutical industries are the primary source of ANP waste. The current review describes various biotic and abiotic methods used in the remediation of ANP drugs in the environment. Abiotic methods often generate transformation products (TPs) of unknown toxicity. In this light, obtaining data on the environmental toxicity of ANPs and its TPs is crucial to determine their toxic effect on the ecosystem. We also discuss the biodegradation of ANP drugs using monoculture of funga... [more]
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