Records Added in February 2021
Records added in February 2021
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Showing records 26 to 50 of 79. [First] Page: 1 2 3 4 Last
Actuator and Sensor Fault Classification for Wind Turbine Systems Based on Fast Fourier Transform and Uncorrelated Multi-Linear Principal Component Analysis Techniques
Yichuan Fu, Zhiwei Gao, Yuanhong Liu, Aihua Zhang, Xiuxia Yin
February 22, 2021 (v1)
Keywords: additive white Gaussian noises (AWGN), fast Fourier transform (FFT), fault classification, fault diagnosis, multi-linear principal component analysis (MPCA), uncorrelated multi-linear principal component analysis (UMPCA), wind turbine systems
In response to the high demand of the operation reliability and predictive maintenance, health monitoring and fault diagnosis and classification have been paramount for complex industrial systems (e.g., wind turbine energy systems). In this study, data-driven fault diagnosis and fault classification strategies are addressed for wind turbine energy systems under various faulty scenarios. A novel algorithm is addressed by integrating fast Fourier transform and uncorrelated multi-linear principal component analysis techniques in order to achieve effective three-dimensional space visualization for fault diagnosis and classification under a variety of actuator and sensor faulty scenarios in 4.8 MW wind turbine benchmark systems. Moreover, comparison studies are implemented by using multi-linear principal component analysis with and without fast Fourier transform, and uncorrelated multi-linear principal component analysis with and without fast Fourier transformation data pre-processing, resp... [more]
Assessing Supply Chain Performance from the Perspective of Pakistan’s Manufacturing Industry Through Social Sustainability
Maryam Khokhar, Wasim Iqbal, Yumei Hou, Majed Abbas, Arooj Fatima
February 22, 2021 (v1)
Keywords: Pakistan, qualitative research, social sustainability, sustainable supply chain management (SSSCM)
The industry is gradually forced to integrate socially sustainable development practices and cross-social issues. Although researchers and practitioners emphasize environmental and economic sustainability in supply chain management (SCM). This is unfortunate because not only social sustainable development plays an important role in promoting other sustainable development programs, but social injustice at one level in the supply chain may also cause significant losses to companies throughout the chain. This article aimed to consolidate the literature on the responsibilities of suppliers, manufacturers, and customers and to adopt sustainable supply chain management (SSSCM) practices in the Pakistani industry to identify all possible aspects of sustainable social development in the supply chain by investigating the relationship between survey variables and structure. This work went beyond the limits of regulations and showed the status of maintaining sustainable social issues. Based on se... [more]
Propagation and Molecular Characterization of Fowl Adenovirus Serotype 8b Isolates in Chicken Embryo Liver Cells Adapted on Cytodex™ 1 Microcarrier Using Stirred Tank Bioreactor
Chidozie C. Ugwu, Mohd Hair-Bejo, Mat I. Nurulfiza, Abdul R. Omar, Aini Ideris
February 22, 2021 (v1)
Subject: Biosystems
Keywords: bioreactor, chicken liver cell, Cytodex 1™ microcarrier, fowl adenovirus 8b, PCR
Large volume production of vaccine virus is essential for prevention and control of viral diseases. The objectives of this study were to propagate Fowl adenovirus (FAdV) isolate (UPM08136) in chicken embryo liver (CEL) cells adapted to Cytodex™ 1 microcarriers using stirred tank bioreactor (STB) and molecularly characterize the virus. CEL cells were prepared and seeded onto prepared Cytodex™ 1 microcarriers and incubated first in stationary phase for 3 h and in STB at 37 °C, 5% CO2, and 20 rpm for 24 h. The CEL cells were infected with FAdV isolate (UPM08136) passage 5 (UPM08136CELP5) or passage 20 (UPM08136CELP20) and monitored until cell detachment. Immunofluorescence, TCID50, sequencing, alignment of hexon and fiber genes, and phylogenetic analysis were carried out. CEL cells were adapted well to Cytodex™ 1 microcarriers and successfully propagated the FAdV isolates in STB with virus titer of 107.5 (UPM08136CELP5B1) and 106.5 (UPM08136CELP20B1) TCID50/mL. These isolates clustered wi... [more]
Surface-Response Analysis for the Optimization of a Carbon Dioxide Absorption Process Using [hmim][Tf2N]
Grazia Leonzio, Edwin Zondervan
February 22, 2021 (v1)
Keywords: Carbon Dioxide Capture, ionic liquid, Optimization, process simulation, statistical analysis
The [hmim][Tf2N] ionic liquid is considered in this work to develop a model in Aspen Plus® capturing carbon dioxide from shifted flue gas through physical absorption. Ionic liquids are innovative and promising green solvents for the capture of carbon dioxide. As an important aspect of this research, optimization is carried out for the carbon capture system through a central composite design: simulation and statistical analysis are combined together. This leads to important results such as the identification of significant factors and their combinations. Surface plots and mathematical models are developed for capital costs, operating costs and removal of carbon dioxide. These models can be used to find optimal operating conditions maximizing the amount of captured carbon dioxide and minimizing total costs: the percentage of carbon dioxide removal is 93.7%, operating costs are 0.66 million €/tonCO2 captured (due to the high costs of ionic liquid), and capital costs are 52.2 €/tonCO2 capt... [more]
Highly-Efficient Caffeine Recovery from Green Coffee Beans under Ultrasound-Assisted SC−CO2 Extraction
Janet Menzio, Arianna Binello, Alessandro Barge, Giancarlo Cravotto
February 22, 2021 (v1)
Keywords: caffeine, green coffee beans, hybrid technology, supercritical CO2 extraction, ultrasound
Natural caffeine from decaffeination processes is widely used by pharmaceutical, cosmetic and soft-drink industries. Supercritical CO2 extraction (SFE−CO2) is extensively exploited industrially, and one of its most representative applications is the decaffeination process, which is a greener alternative to the use of organic solvents. Despite its advantages, extraction kinetics are rather slow near the CO2 critical point, meaning that improvements are highly sought after. The effect exerted by a combination of SFE−CO2 and ultrasound (US−SFE−CO2) has been investigated in this preliminary study, with the aim of improving mass transfer and selectivity in the extraction of caffeine from green coffee beans. This hybrid technology can considerably enhance the extraction efficiency and cut down process time. Further studies are in progress to demonstrate the complete decaffeination of green coffee beans of different types and origins.
Preliminary Insights into Electro-Sensitive Ecolubricants: A Comparative Analysis Based on Nanocelluloses and Nanosilicates in Castor Oil
Moisés García-Morales, Samuel D. Fernández-Silva, Claudia Roman, Marius A. Olariu, Maria T. Cidade, Miguel A. Delgado
February 22, 2021 (v1)
Subject: Materials
Keywords: castor oil, dielectric spectroscopy, ecolubricants, electro-rheology, nanocellulose, nanoclays, nanofluids, smarts fluids
The newest generation of lubricants needs to adapt to stricter environmental policies. Simple and sustainable formulations with tunable rheological properties under the action of electric potentials may be the key. The present research explored the feasibility of producing electro-sensitive ecolubricants based on nanocellulose (crystalline and fibrillar) or nanoclay (Cloisite 15A montmorillonite and halloysite nanotubes) dispersions in castor oil, at concentrations that ranged from 2 to 6 wt.%. Broadband dielectric spectroscopy (BDS) measurements allowed for a first estimate on the electro-responsive potential of the nanofluids. The nanocelluloses and the montmorillonite suspensions presented a relaxation event in the dielectric loss, ε″, centered at ca. 2−4 kHz, which is related to interfacial polarization. Moreover, their actual electro-rheological (ER) effect under high electric potentials up to 4 kV/mm was assessed by determining the magnitude of the yield stress from steady flow c... [more]
Improvement of Fast Kurtogram Combined with PCA for Multiple Weak Fault Features Extraction
Yongxing Song, Jingting Liu, Linhua Zhang, Dazhuan Wu
February 22, 2021 (v1)
Keywords: demodulation, fast kurtogram, multiple weak fault features extraction, principal component analysis
Demodulation plays an important role in fault feature extraction for rotating machinery. The fast kurtogram method was proved to be effective for rotating machinery demodulation. However, the demodulation effectiveness of fast kurtogram was poor for multiple fault features extraction under low signal-to-noise ratio. In this paper, an improved method of fast kurtogram, called P-kurtogram, is presented. The proposed method extracted the multiple weak fault features from multiple envelope signals-based principal component analysis. Compared with extracting features from one envelope signal of fast kurtogram, P-kurtogram showed a better demodulation performance for multiple faults. Combined with principal component analysis method, the proposed method also showed a good performance under low signal-to-noise ratio(SNR). By simulation analysis, the P-kurtogram method showed good performance for multiple modulation features extraction and robust performance in demodulation under low SNR. Then... [more]
Molecular Identification and VOMs Characterization of Saccharomyces cerevisiae Strains Isolated from Madeira Region Winery Environments
Mariangie Castillo, Emanuel da Silva, José S. Câmara, Mahnaz Khadem
February 22, 2021 (v1)
Keywords: Demarcated Region of Madeira, molecular identification, Saccharomyces cerevisiae, strain, volatile organic metabolites
The quality and typical characteristic of wines depends, among other factors, on the volatile organic metabolites (VOMs) that are biosynthesized by yeasts, mainly Saccharomyces cerevisiae species. The yeast strain influences the diversity and proportions of the VOMs produced during the fermentation process, as the genetic predisposition of the strains is a by-product of selective adaptation to the ecosystem. The present work reports the characterization of S. cerevisiae strains isolated from grape must, used in the Demarcated Region of Madeira (DRM) for winemaking. Yeast species were identified by amplification and by restriction fragment length polymorphism (RFLP) analysis of the region 5.8S-internal transcribed spacers (PCR-RFLP of 5.8S-ITS) of ribosomal DNA (rDNA). The strains identification was performed by analyzing the RFLP pattern of mitochondrial DNA (RFLP-mtDNA). The representative strains were selected for the characterization of the volatile profile through headspace solid-p... [more]
Research on the Dynamic Characteristics of Mechanical Seal under Different Extrusion Fault Degrees
Yin Luo, Yakun Fan, Yuejiang Han, Weqi Zhang, Emmanuel Acheaw
February 22, 2021 (v1)
Keywords: dynamic characteristics, extrusion fault, fluent, mechanical seal, numerical simulation, sealing performance
In order to explore the dynamic characteristics of the mechanical seal under different fault degrees, this paper selected the upstream pumping mechanical seal as the object of study. The research established the rotating ring-fluid film-stationary ring 3D model, which was built to analyze the fault mechanism. To study extrusion fault mechanism and characteristics, different dynamic parameters were used in the analysis process. Theoretical analysis, numerical simulation, and comparison were conducted to study the relationship between the fault degree and dynamic characteristics. It is the first time to research the dynamic characteristics of mechanical seals in the specific extrusion fault. This paper proved feasibility and effectiveness of the new analysis method. The fluid film thickness and dynamic characteristics could reflect the degree of the extrusion fault. Results show that the fluid film pressure fluctuation tends to be more intensive under the serious extrusion fault conditio... [more]
Process of Obtaining Chromium Nitride in the Combustion Mode under Conditions of Co-Flow Filtration
Nikolay Evseev, Mansur Ziatdinov, Vladimir Romandin, Alexander Zhukov, Aidos Tolynbekov, Yuliya Ryzhikh
February 22, 2021 (v1)
Keywords: chromium nitride, co-flow, filtration combustion, inverse combustion wave, nitrogen–argon mixture, self-propagating high-temperature synthesis, superadiabatic heating
In this work, the combustion process of chromium powder in the co-flow filtration mode was studied. The effect of nitrogen-containing gas flow rate on the nitridation of combustion products is shown. The effect of the amount of argon in the nitrogen−argon mixture on the burning rate and the burning temperature of the chromium powder is shown. It was found that an increase in the percentage of argon in the nitrogen−argon mixture can lead to the formation of an inverse combustion wave. The actual burning temperature is higher than adiabatic burning temperature in the co-flow filtration mode, thus the phenomenon of superadiabatic heating is observed. The phase composition of the obtained combustion products was studied. It was shown that the forced filtration mode allows for synthesizing non-stoichiometric Cr2N nitride.
Establish Induction Motor Fault Diagnosis System Based on Feature Selection Approaches with MRA
Chun-Yao Lee, Meng-Syun Wen
February 22, 2021 (v1)
Keywords: artificial neural network, correlation and fitness value-based feature selection, correlation-based feature selection, Fault Detection, feature selection, multiresolution analysis
This paper proposes a feature selection (FS) approach, namely, correlation and fitness value-based feature selection (CFFS). CFFS is an improvement feature selection approach of correlation-based feature selection (CFS) for the common failure cases of the induction motor. CFFS establishes the induction motor fault detection (FD) system with artificial neural network (ANN). This study analyzes the current signal of the induction motor with multiresolution analysis (MRA), extracts the features, and uses feature selection approaches (ReliefF, CFS, and CFFS) to reduce the number of features and maintain the accuracy of the induction motor fault detection system. Finally, the induction motor fault detection system is trained by the feature selection approaches selected features. The best induction motor fault detection system will be established through the comparison of the efficiency of these FS approaches.
Electrochemiluminescence Enhancement and Particle Structure Stabilization of Polymer Nanoparticle by Doping Anionic Polyelectrolyte and Cationic Polymer Containing Tertiary Amine Groups and Its Highly Sensitive Immunoanalysis
Noor Ul Ain, Tian-Yu Wang, Xiao-Ning Wu, Tong-Hong Wei, Jing-Shuo Zhang, Hong-Ping Xie
February 22, 2021 (v1)
Subject: Materials
Keywords: doping, electrochemiluminescence nanoparticle, immunoanalysis, ionic polymer, particle structure stabilization, signal enhancement
A doped polymer nanoparticle (dPNP) of electrochemiluminescence (ECL) was prepared via doping the anionic polyelectrolyte polyacrylic acid (PAA) and the cationic polymer poly-ethyleneimine (PEI) into the polymer nanoparticle (PNP), which was self-assembled by Ru(bpy)32+ derivative-grafted PAA (PAA−Ru) with both cations and anions. The good electrical conductivity of the doped polyelectrolyte PAA enhanced the ECL intensity of PNP to 109.1%, and the involvement of a large number of tertiary amine groups of the doped PEI further enhanced that to 127.3%; meanwhile, doping low-molecular-weight PEI into PNP, while simultaneously doping high-molecular-weight PAA, avoided the precipitation of PAA and PEI, due to interaction of the two oppositely charged polymers; and these also made the self-assembly procedure more effective and the nanoparticle structure more stable than PNP and also led to the production of rich residual PAA chains on the surface of dPNP. The storage results showed that the... [more]
The Fabrication of Geopolymer Foam Composites Incorporating Coke Dust Waste
Buczkowska Katarzyna, Chi Hiep Le, Petr Louda, Szczypiński Michał, Totka Bakalova, Pacyniak Tadeusz, Karol Prałat
February 22, 2021 (v1)
Subject: Materials
Keywords: coke dust waste, compressive strength, flexural strength, geopolymer foam, thermal conductivity
This paper reports the results of an experimental investigation on the mechanical properties of geopolymer foams incorporating filler from the coke dust waste (CDW). In this work, CDW was used to replace a part of geopolymer paste at 5%, 10%, 20%, and 30% by geopolymer binder mass. The physico-mechanical properties and thermal resistance against high temperatures of CDW/geopolymer foams are presented. The primary results obtained show that the use of CDW in the production of geopolymer foam composites made it possible for them to achieve relatively good mechanical properties. However, the incorporation of the CDW into the geopolymer had a slightly negative effect on thermal conductivity, but significantly improved the mechanical strength of the final product. Moreover, this waste also helped the composite foam to achieve a structure with more uniform open pores distribution, compared to the pure foam. After exposure to elevated temperatures, the residual strength of the composite foams... [more]
Is Anoxic Operation Effective to Control Nitrate Build-Up and Sludge Loss for the Combined Partial Nitritation and Anammox (CPNA) Process?
Hongyan Wang, Yuanyue Wang, Junya Zhang, Qianwen Sui, Dazhou Hu, Fumin Zuo, Yuansong Wei
February 22, 2021 (v1)
Keywords: CPNA, nitrate build-up, sludge loss, start-up
There were three main issues of long start-up period, nitrate build-up and sludge loss during the operation of combined partial-nitritation anammox (CPNA). To fully start up the CPNA reactor, the fast achievement of partial-nitritation (PN) was the first step. Firstly, the PN process was successfully achieved within 22 days by 2 mg·L−1 hydroxylamine (NH2OH) addition and online intermittent aeration control at 0.2~0.3 mg·L−1 dissolved oxygen (DO). Then, a novel strategy of adding anoxic stirring phase between feeding and aeration period during CPNA operation was applied. It was shown effective to control nitrate build-up since the mole ratio of NO3−-N production and NH4+-N removed (MNRR) was mostly below 15%. Also, the procedure adjustment was proven useful to alleviate sludge loss by sustaining filamentous bacteria that could act as biomass framework and reduce nitrate substrate. The filamentous denitrifying bacteria could cause sludge bulking. The total nitrogen removal rate (TNRR) va... [more]
A Laboratory Approach on the Hybrid-Enhanced Oil Recovery Techniques with Different Saline Brines in Sandstone Reservoirs
Yisheng Hu, Qiurong Cheng, Jinping Yang, Lifeng Zhang, Afshin Davarpanah
February 22, 2021 (v1)
Subject: Other
Keywords: cumulative oil production, foam flooding, low-salinity water, sandstone reservoirs, wettability change
As foams are not thermodynamically stable and might be collapsed, foam stability is defined by interfacial properties and bulk solution. In this paper, we investigated foam injection and different salinity brines such as NaCl, CaCl2, KCl, and MgCl2 to measure cumulative oil production. According to the results of this experiment, it is concluded that sequential low-salinity water injections with KCl and foam flooding have provided the highest cumulative oil production in sandstone reservoirs. This issue is related to high wettability changes that had been caused by the KCl. As K+ is a monovalent cation, KCl has the highest wettability changes compared to other saline brines and formation water at 1000 ppm, which is due to the higher wettability changes of potassium (K+) over other saline ions. The interfacial tension for KCl at the lowest value is 1000 ppm and, for MgCl2, has the highest value in this concentration. Moreover, the formation brine, regarding its high value of salty compo... [more]
Diospyrin Modulates Inflammation in Poly I:C-Induced Macrophages via ER Stress-Induced Calcium-CHOP Pathway
Hyun-Ju Kim, Inamullah Khan, Adnan Shahidullah, Syed Muhammad Ashhad Halimi, Abdur Rauf, Ji-Young Lee, Young-Jin Kim, Bong-Youn Kim, Wansu Park
February 22, 2021 (v1)
Subject: Biosystems
Keywords: calcium, CHOP, cytokine, diospyrin, ER stress, ERK1/2, p38 MAPK, poly I:C, STAT, viral infection
Diospyrin, plant-derived bisnaphthoquinonoid, is known to have anticancer activity. However, pharmacological activity of diospyrin on viral infection is not well known. We investigated effects of diospyrin on macrophages induced by polyinosinic-polycytidylic acid (poly I:C), a mimic of double-stranded viral RNA. Various cytokines, intracellular calcium, nitric oxide (NO), phosphorylated p38 MAPK, and phosphorylated ERK1/2 as well as mRNA expressions of transcription factors were evaluated. Diospyrin significantly reduced NO production, granulocyte-macrophage colony-stimulating factor production, and intracellular calcium release in poly I:C-induced RAW 264.7. The phosphorylation of p38 MAPK and ERK1/2 was also significantly suppressed. Additionally, diospyrin inhibited mRNA levels of nitric oxide synthase 2, C/EBP homologous protein (CHOP), calcium/calmodulin dependent protein kinase II alpha, signal transducers and activators of transcription 1 (STAT1), STAT3, STAT4, Janus kinase 2, f... [more]
Study on the Law of Diesel Oil Carrying Water in Lanzhou−Chengdu−Chongqing Product Oil Pipeline Based on Large Eddy Simulation
Tao Zhang, Bin Chen, Kun Sun, Wenjie Chang
February 22, 2021 (v1)
Keywords: flow pattern, Lanzhou–Chengdu–Chongqing product oil pipeline, LES, VOF, water carrying capacity of oil
Water accumulation at the bottom of the product oil pipeline will lead to corrosion damage to the pipeline. The study on water carrying laws of refined oil could provide a reference for the safe operation of the pipeline. In this paper, the actual size of Lanzhou−Jiangyou section of Lanzhou−Chengdu−Chongqing pipeline was taken as the pipeline size. The volume of fluid (VOF) model of oil-water two-phase flow based on large eddy simulation (LES) was established. The numerical simulation of the water-carrying behavior of the product oil in the inclined pipeline was carried out. The LES-based two-phase flow model can capture the characteristics of stratified flow, wavy stratified flow, and dispersed flow under various operating conditions. The model was applied to simulate the water carrying process under various oil inlet velocities and the inclined pipe angles. The results show that as the pipeline inclined angle is 10~20° and the oil inlet velocity is 0.66 m/s, the flow patterns in the... [more]
Determination of Hemicellulose, Cellulose, and Lignin Content in Different Types of Biomasses by Thermogravimetric Analysis and Pseudocomponent Kinetic Model (TGA-PKM Method)
David Díez, Ana Urueña, Raúl Piñero, Aitor Barrio, Tarja Tamminen
February 22, 2021 (v1)
Keywords: Biomass, cellulose, hemicellulose, lignin, pseudocomponent kinetic model, TGA
The standard method for determining the biomass composition, in terms of main lignocellulosic fraction (hemicellulose, cellulose and lignin) contents, is by chemical method; however, it is a slow and expensive methodology, which requires complex techniques and the use of multiple chemical reagents. The main objective of this article is to provide a new efficient, low-cost and fast method for the determination of the main lignocellulosic fraction contents of different types of biomasses from agricultural by-products to softwoods and hardwoods. The method is based on applying deconvolution techniques on the derivative thermogravimetric (DTG) pyrolysis curves obtained by thermogravimetric analysis (TGA) through a kinetic approach based on a pseudocomponent kinetic model (PKM). As a result, the new method (TGA-PKM) provides additional information regarding the ease of carrying out their degradation in comparison with other biomasses. The results obtained show a good agreement between exper... [more]
Exploring E-Waste Resources Recovery in Household Solid Waste Recycling
Muhammad Mobin Siddiqi, Muhammad Nihal Naseer, Yasmin Abdul Wahab, Nor Aliya Hamizi, Irfan Anjum Badruddin, Mohd Abul Hasan, Zaira Zaman Chowdhury, Omid Akbarzadeh, Mohd Rafie Johan, Sarfaraz Kamangar
February 22, 2021 (v1)
Keywords: household solid waste, metal recovery value, socio-economic benefits, waste composition of Karachi-Pakistan, waste management, waste recycling
The ecosystem of earth, the habitation of 7.53 billion people and more than 8.7 million species, is being imbalanced by anthropogenic activities. The ever-increasing human population and race of industrialization is an exacerbated threat to the ecosystem. At present, the global average waste generation per person is articulated as 494 kg/year, an enormous amount of household waste (HSW) that ultimately hits 3.71×1012 kg of waste in one year. The ultimate destination of HSW is a burning issue because open dumping and burning as the main waste treatment and final disposal systems create catastrophic environmental limitations. This paper strives to contribute to this issue of HSW management that matters to everyone’s business, specifically to developing nations. The HSW management system of the world’s 12th largest city and 24th most polluted city, Karachi, was studied with the aim of generating possible economic gains by recycling HSWs. In this regard, the authors surveyed dumping sites... [more]
Special Issue on “Design and Control of Sustainable Processes”
Sujit S. Jogwar, Xiaonan Wang
February 22, 2021 (v1)
Sustainability has been one of the key drivers for technological innovation in this century [...]
Effect of Bio-Oil Species on Rheological Behaviors and Gasification Characteristics of Coal Bio-Oil Slurry Fuels
Ping Feng, Jie Li, Jinyu Wang, Huan Wang, Zhiqiang Xu
February 22, 2021 (v1)
Keywords: bio-oil, coal slurry, gasification, lignite, rheological behavior
Bio-oil is a promising fuel as one of the main products from biomass fast pyrolysis for improving energy density and reducing transportation cost, but high acidity and low calorific value limit its direct application. It can be used to prepare coal bio-oil slurry as partial green fuels for potential feeds for synthesis gas production via gasification with the advantages over traditional coal-water slurries of calorific values and being additives-free. In the present work, three bio-oils were blended with lignite to prepare slurry fuels for the investigation of the effect of bio-oil species on rheological behaviors and gasification characteristics of coal bio-oil slurry fuels. Results show that slurry prepared with bio-oil from fruit tree pyrolysis is highly viscous and has higher activation energy in gasification. Slurries prepared with bio-oils from straw pyrolysis and pyroligneous acid from wood pyrolysis exhibited an acceptably lower viscosity, and the gasification temperatures were... [more]
Modeling the Effect of Scrap on the Electrical Energy Consumption of an Electric Arc Furnace
Leo S. Carlsson, Peter B. Samuelsson, Pär G. Jönsson
February 22, 2021 (v1)
Keywords: Electric Arc Furnace, electrical energy consumption, scrap melting, statistical modeling
The melting time of scrap is a factor that affects the Electrical Energy (EE) consumption of the Electric Arc Furnace (EAF) process. The EE consumption itself stands for most of the total energy consumption during the process. Three distinct representations of scrap, based partly on the apparent density and shape of scrap, were created to investigate the effect of scrap on the accuracy of a statistical model predicting the EE consumption of an EAF. Shapley Additive Explanations (SHAP) was used as a tool to investigate the effects by each scrap category on each prediction of a selected model. The scrap representation based on the shape of scrap consistently resulted in the best performing models while all models using any of the scrap representations performed better than the ones without any scrap representation. These results were consistent for all four distinct and separately used cleaning strategies on the data set governing the models. In addition, some of the main scrap categorie... [more]
Optimization of Polymer Extrusion Die Based on Response Surface Method
Amin Razeghiyadaki, Dichuan Zhang, Dongming Wei, Asma Perveen
February 22, 2021 (v1)
Keywords: design optimization, manufacturing process design, polymer processing, response surface method, sheet die design
A coupled surface response optimization method with a three-dimensional finite volume method is adopted in this study to identify five independent geometric variables of the die interior that provides a design with the lowest velocity variance at the exit of the coat-hanger extrusion die. Two of these five geometric variables represent the manifold dimension while the other three variables represent the die profile. In this method, B-spline fitting with four points was used to represent the die profile. A comparison of the optimized die obtained in our study and the die with a geometry derived by a previous theoretical work shows a 20.07% improvement in the velocity distribution at the exit of the die.
Research on Improved Intelligent Control Processes Based on Three Kinds of Artificial Intelligence
Jingwei Liu, Tianyue Li, Jiaming Chen, Fangling Zuo
February 22, 2021 (v1)
Keywords: expert PID, fuzzy PID, intelligent control, online tuning for control parameters, wavelet neural network PID
Autotuning and online tuning of control parameters in control processes (OTP) are widely used in practice, such as in chemical production and industrial control processes. Better performance (such as dynamic speed and steady-state error) and less repeated manual-tuning workloads in bad environments for engineers are expected. The main works are as follows: Firstly, a change ratio for expert system and fuzzy-reasoning-based OTP methods is proposed. Secondly, a wavelet neural-network-based OTP method is proposed. Thirdly, comparative simulations are implemented in order to verify the performance. Finally, the stability of the proposed methods is analyzed based on the theory of stability. Results and effects are as follows: Firstly, the proposed control parameters of online tuning methods of artificial-intelligence-based classical control (AI-CC) systems had better performance, such as faster speed and smaller error. Secondly, stability was verified theoretically, so the proposed method c... [more]
Evaluation of Water Hammer for Seawater Treatment System in Offshore Floating Production Unit
Jun Sung Park, Quang Khai Nguyen, Gang Nam Lee, Kwang Hyo Jung, Hyun Park, Sung Bu Suh
February 22, 2021 (v1)
Keywords: method of characteristics, seawater treatment system, valve flow coefficient, water hammer
Water hammer can result in the rupture of pipes, and significant damage to pipe supports is inevitable during the operation of an offshore plant. In this study, the dynamic behaviors of the water hammer caused by closing valves and starting pumps for the seawater treatment system were evaluated by using the 1D numerical simulation model based on the method of characteristics. Before conducting an analysis of a complex piping network, the 1D numerical simulation tools were validated by a comparison between the numerical results and the results from both static and transient experiments that have been conducted in other studies. For the case study, the effects of valve flow characteristics and valve closing time on surge pressure were investigated, and the equal percentage butterfly valve was recommended in order to reduce the surge pressure with a shorter valve closure time and lower weight compared to other valve types.
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