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Assessing the Sustainability of Industrial Equipment Life Extension Strategies through a Life Cycle Approach: Methodology and Practical Guidelines
Ludovica Rossi, Deborah Leone, Andrea Barni, Alessandro Fontana
February 21, 2023 (v1)
Keywords: circularity indicators, circularity strategies, decision support framework, End-of-Life circular strategies, life cycle extension strategies, sustainability and circularity, sustainability and circularity assessment framework
Nowadays, Circular Economy (CE) is shifting from a nice-to-have marketing operation to a business development strategy that is central to the restoring and preservation of our natural ecosystem. However, despite motivated promotion efforts, the concrete application of this model at the micro-level is still in its infancy due to several challenges that companies face. One of these challenges is the uncertainty that businesses have in the estimation of the actual impact that adopting CE strategies can have on their activities from an environmental and economic perspective. This work aims to define a conceptual framework to be applied to the Life Cycle Extension Strategies (LCES) of products, which is meant to understand whether the application of a strategy is beneficial from an environmental and economic point of view. In order to address the identified need, a list of indicators to be exploited in the LCES performance analysis has been designed and divided into the two categories of en... [more]
Individualized Dosage Optimization for Myeloablative Conditioning before Unrelated Cord Blood Transplantation in a Diamond−Blackfan Anemia Patient with Germline RPL11 Mutation: A Case Study
Rong-Long Chen, Li-Hua Fang, Liuh-Yow Chen
February 21, 2023 (v1)
Subject: Optimization
Keywords: Diamond–Blackfan anemia, myeloablative conditioning, population pharmacokinetics model, therapeutic drug monitoring, unrelated cord blood transplantation
Unrelated cord blood transplantation (CBT) for Diamond−Blackfan anemia (DBA), a systemic ribosomopathy affecting the disposition of conditioning agents, has resulted in outcomes inferior to those by transplantations from matched donors. We report the experience of the pharmacokinetics-guided myeloablative unrelated CBT in a DBA patient with a germline RPL11 mutation. The conditioning consisted of individualized dosing of fludarabine (based on weight and renal function with a target area under the curve (AUC) of 17.5 mg·h/L) and busulfan (based on therapeutic drug monitoring with a target AUC of 90 mg·h/L), as well as dosing and timing of thymoglobulin (based on body weight and pre-dose lymphocyte count to target pre-CBT AUC of 30.7 AU·day/mL and post-CBT AUC of 4.3 AU·day/mL, respectively). The pharmacokinetic measures resulted in a 27.5% reduction in busulfan and a 35% increase in fludarabine, as well as an over three-fold increase in thymoglobulin dosage with the start time changed t... [more]
Growth Enhancement of Camellia sinensis with Biochar
Herta Novalina Sipayung, Keng-Tung Wu, De-Yu Liu, Chien-Teh Chen
February 21, 2023 (v1)
Subject: Environment
Keywords: biochar, field study, soil amendment, sustainable farming, tea production
Biochar application in the agriculture sector is a practical approach to minimize waste and maintain sustainable farming. However, the information regarding biochar application in tea cultivation is limited and especially rare in field research. In this study, a two-year biochar experiment was conducted in a tea yard subject to tea yield and soil characteristics. According to tea growth, the tea yard for the experiment was divided into weak and normal sectors. Biochar was made from tea processing waste, mainly the twigs. The results showed that biochar application increased tea production by 2.3- and 1.3-fold in the weak and normal sectors, respectively, suggesting that converting tea waste to biochar for soil amendment is beneficial to increasing tea production, particularly in the weak sector. The regression analysis on tea production and soil characteristics revealed that only soil electric conductivity (R2 = 0.6597), soil organic matter (R2 = 0.7024), and soil extractable phosphate... [more]
Analysis of Fe(II)-Ni(II) Electrochemical Reduction Process and Electrodeposition of FeNi Films
Yanling Qi, Chenchen He, Run Zhang, Wei Wang
February 21, 2023 (v1)
Keywords: ammonium sulfate, boric acid, coercivity, FeNi alloy, saturation magnetization
The effects of boric acid and ammonium sulfate on the electrochemical reduction process of Fe(II) Ni(II) were studied. A series of FeNi thin films were prepared by electrodeposition with different current density and Fe(II) concentration in solution. Linear sweep voltammetry (LSV) results show that the reduction current of Fe(II) is higher than that of Ni(II) at the same concentration of Fe(II) and Ni(II) as well as the same electrodeposition parameters. Adding H3BO3 to Fe(II) Ni(II) solution is beneficial to obtain brighter and compact coating, and adding (NH4)2SO4 is beneficial to obtain higher reduction current density. Energy dispersive X-Ray spectroscopy (EDS) results show that the current density has a significant and nonlinear effect on the Fe content in FeNi thin films. The highest Fe content is obtained at a current density of 25 A∙cm−2. SEM results show that the surface morphology of FeNi films is controlled by the content of Ni and Fe in the films. With increasing Fe content... [more]
A Conceptual Comparison of Six Nature-Inspired Metaheuristic Algorithms in Process Optimization
Shankar Rajendran, Ganesh N., Robert Čep, Narayanan R. C., Subham Pal, Kanak Kalita
February 21, 2023 (v1)
Subject: Optimization
Keywords: Algorithms, non-traditional algorithms, Optimization, process optimization, process parameters
In recent years, several high-performance nature-inspired metaheuristic algorithms have been proposed. It is important to study and compare the convergence, computational burden and statistical significance of these metaheuristics to aid future developments. This study focuses on six recent metaheuristics, namely, ant lion optimization (ALO), arithmetic optimization algorithm (AOA), dragonfly algorithm (DA), grey wolf optimizer (GWO), salp swarm algorithm (SSA) and whale optimization algorithm (WOA). Optimization of an industrial machining application is tackled in this paper. The optimal machining parameters (peak current, duty factor, wire tension and water pressure) of WEDM are predicted using the six aforementioned metaheuristics. The objective functions of the optimization study are to maximize the material removal rate (MRR) and minimize the wear ratio (WR) and surface roughness (SR). All of the current algorithms have been seen to surpass existing results, thereby indicating the... [more]
Overview of Gene Expression Analysis in Gastric Disease Infected with Helicobacter pylori: CLDN1 and MMP9 Could Be Biomarkers for Early Diagnosis of Gastric Cancer
Claudia Ivette Rivas-Ortiz, Stephanie Euridice Morales-Guerrero, Sergio Ponce-de-León-Rosales, Armando Gamboa-Domínguez, Claudia Rangel-Escareño, Luis Federico Uscanga-Domínguez, Germán Rubén Aguilar-Gutiérrez, David Kershenobich-Stalnikowitz, Yolanda López-Vidal, Gonzalo Castillo-Rojas
February 21, 2023 (v1)
Subject: Biosystems
Keywords: biomarkers, chronic atrophic gastritis, gastric cancer, gene expression, Helicobacter pylori, immunohistochemistry, microarray, qPCR
Chronic Helicobacter pylori infection produces several lesions in the human stomach, which can progress to chronic atrophic gastritis and gastric cancer. To date, there is very little information on gene expression in chronic atrophic gastritis and its relationship with progression to gastric cancer. In this study, we performed a gene expression analysis during chronic atrophic gastritis in order to identify possible biomarkers that allow an early diagnosis of gastric cancer. We studied biopsies from patients with chronic atrophic gastritis and gastric cancer. The biopsies were analyzed by a gene expression microarray and corroborated by qPCR and validated through immunohistochemistry. Our results revealed that gene expression profiles in patients with chronic atrophic gastritis showed molecular changes of the gastric mucosa, leading to gastric cancer. The gene expression profiles of CLDN1, CLDN7, OLFM4, C-MYC and MMP9 were more notable from the chronic atrophic gastritis. The gene exp... [more]
Synthesis of a Ternary Polysulfonate Dispersant and Its Suspension Performance
Kemei Pei, Yongjie Huang, Xiao Yu, Dekai Wang
February 21, 2023 (v1)
Subject: Materials
Keywords: dispersion properties, environmental material, pendimethalin, polysulfonate dispersant, suspension
Allyl alcohol polyoxyethylene ether (APEG), hydroxyethyl methacrylate (HEMA) and styrene sodium sulfonate (SSS) were used as monomers to obtain a APEG-HEMA-SSS comb-like polymer, which was employed as the polysulfonate dispersant for pendimethalin suspensions in this paper. The comb-like polymer has an anionic polysulfonate backbone, hydrophilic APEG side chains and sulfonic acid groups, which makes the dispersant absorb easily on the surface of pendimethalin particles. The polysulfonate dispersant with good dispersion performance was screened out by orthogonal experiments. The surface tension, zeta potential, particle size and dynamic contact angle of the pendimethalin suspension with APEG-HEMA-SSS as dispersant were investigated. The dispersant improves the dispersibility and wettability of the pendimethalin suspension observably.
Planning Method and Principles of the Cloud Energy Storage Applied in the Power Grid Based on Charging and Discharging Load Model for Distributed Energy Storage Devices
Junfang Li, Yue Xing, Donghui Zhang
February 21, 2023 (v1)
Keywords: cloud energy storage system, demand response, electric vehicles, ice storage system, load modelling, Monte Carlo simulation, power system planning, shared distributed energy storage system
The cloud energy storage system (CES) is a shared distributed energy storage resource. The random disordered charging and discharging of large-scale distributed energy storage equipment has a great impact on the power grid. This paper solves two problems. On one hand, to present detailed plans for designing an orderly controlled CES system in a realistic power system. On the other hand, Monte Carlo simulation (MCS) is used for analyzing the load curves of five types of distributed energy storage systems to manage and operate the CES system. A method of its planning and the principles of CES for applied in a power grid, are presented by analyzing the impact based on five load curves including the electric vehicle (EV), the ice storage system, the demand response, the heat storage system, and the decentralized electrochemical energy storage system. The MCS simulates the random charging and discharging of the system over a five-year planned scaling of distributed energy storage from 2021... [more]
Preparation and Properties of Impact Resistant Polyurea Coating for Fluorochemical Pipeline
Gang Wu, Zhou Fang, Xuan Qin, Junjie Fu
February 21, 2023 (v1)
Keywords: fluorochemical pipeline, impact resistant, numerical simulation, polyurea
A new type of high elastic polyurea protective coating reinforced by nano silica is prepared by filler composite in order to avoid both the leakage of fluorine chemical pipelines containing highly toxic and dangerous media as well as the damage to fluorine chemical pipelines under impact loads. The aim is to improve the intrinsic safety of fluorine chemical pipelines and ensure the safety of the ecological environment, life and property. The effects of different processes and process parameters on the properties of polyurea coating were studied. The polyurea coating was blended and strengthened with nano silica modified by silane coupling agent KH-550. The suitable stirring speed, material addition sequence and nano silica concentration of the new polyurea material were put forward to prepare a new polyurea coating with excellent properties. The properties of the polyurea coating were characterized, including curing time, tensile strength, elongation at break and impact resistance. The... [more]
Influence of 12Cr1MoV Material on Tissue Properties at High Temperature and Long Operating Time
Jiawei Liu, Yuanzhe Li
February 21, 2023 (v1)
Subject: Materials
Keywords: 12Cr1MoV, carbide precipitation phase, high temperatures and long operating times, solid solution strengthening
12Cr1MoV is commonly used for pressure pipes in thermal power plants. However, its service life has always prevented the development of such metallic materials. This experiment applies a tensile and impact experiment to investigate the metal cluster of 12Cr1MoV low-alloy and heat-resistant steel with 60,000 h service at 550 °C. Results indicate that, after 60,000 h of high-temperature exposure, the metal cluster of Cr, Mo, and V elements may gradually decrease. First, the decreasing elements will precipitate out of the solid solution. Then, the precipitated elements transform into carbides that accumulate and grow on the grain boundaries. The continuous growth of the precipitated carbide of alloy elements may also create pearlite in the cluster, which results in severe pearlite periodization and tensile fracture due to plastic, through-crystal fracture. Then, the solid solution-strengthened tissue disappears, which severely decreases the thermal strength of 12Cr1MoV low-alloy and heat-... [more]
Energy Analysis on Wheat Yield of Mongolian Agriculture
Lyankhua Bayasgalankhuu, Sara Ilahi, Wenshan Wei, Yongchang Wu
February 21, 2023 (v1)
Keywords: agricultural energy use, input–output energy, Mongolian agriculture, wheat yield
Agricultural policies should be aimed at enhancing production per unit area and help to reduce the cultivated area. To that end, it is critical to conserve soil fertility, promote ecological agriculture, employ climate change adaptation technology, significantly enhance irrigated agriculture, and decrease agricultural production risks. Sustainable agricultural production requires optimized land usage, increased energy efficiency, reduced use of fossil fuels, and minimized environmental consequences. Energy has been used in agriculture in a dramatically increased manner, and the agri-food chain now accounts for 30% of the total global energy use. Energy analysis quantifies the amount of energy used in agricultural production, so it may be used to optimize energy consumption and boost energy efficiency, further propelling the sustainable development of agriculture. Recently, the Mongolian government has expressed concerns about how to realize food sustainability and self-sufficiency in w... [more]
Isolation and Purification of Mustard Glucosinolates by Macroporous Anion-Exchange Resin: Process Optimization and Kinetics’ Modelling
Mathieu Hebert, Emmanuel Serra, Eugène Vorobiev, Houcine Mhemdi
February 21, 2023 (v1)
Keywords: anion-exchange resin, gluconapin, Mustard glucosinolates, purification, sinigrin
Glucosinolates (GSL) (β-thioglucoside-N-hydroxy sulfates) are rich-sulfur secondary metabolites raising potential biofumigation interest due to their biological properties. Sinigrin and gluconapin are the main glucosinolates present in brown mustard seeds (Brassica juncea). These glucosinolates are very suitable for the development of phytosanitary products due to their fungicidal, bactericidal and insecticidal effects. In this work, the purification of sinigrin and gluconapin extracted from defatted mustard seeds was studied using macroporous anion exchange resins. A strongly and a weakly anionic resin were first tested according to the nature of their functional group and through their selectivity towards glucosinolates. Anion-exchange resin purification was first studied in static (batch) mode in order to determine the optimal operating conditions; it was then tested in a dynamic (continuous) mode (column) to validate the process. In static mode, the adsorption behavior and characte... [more]
Modern Sensor Tools and Techniques for Monitoring, Controlling, and Improving Cell Culture Processes
Sebastian Juan Reyes, Yves Durocher, Phuong Lan Pham, Olivier Henry
February 21, 2023 (v1)
Keywords: bioprocess, cell culture, monitoring, PAT, sensors, smart biomanufacturing, soft-sensor, spectroscopy
The growing biopharmaceutical industry has reached a level of maturity that allows for the monitoring of numerous key variables for both process characterization and outcome predictions. Sensors were historically used in order to maintain an optimal environment within the reactor to optimize process performance. However, technological innovation has pushed towards on-line in situ continuous monitoring of quality attributes that could previously only be estimated off-line. These new sensing technologies when coupled with software models have shown promise for unique fingerprinting, smart process control, outcome improvement, and prediction. All this can be done without requiring invasive sampling or intervention on the system. In this paper, the state-of-the-art sensing technologies and their applications in the context of cell culture monitoring are reviewed with emphasis on the coming push towards industry 4.0 and smart manufacturing within the biopharmaceutical sector. Additionally,... [more]
Advancements in the Conversion of Lipid-Rich Biowastes and Lignocellulosic Residues into High-Quality Road and Jet Biofuels Using Nanomaterials as Catalysts
Max J. A. Romero, Daniele Duca, Giuseppe Toscano
February 21, 2023 (v1)
Subject: Materials
Keywords: biofuel, biowaste, deoxygenation, lignin-first approach, lignocellulosic residue, nanomaterial
At present, the majority of available road and jet biofuels are produced from oleochemical feedstocks that include vegetable oils and biowastes such as waste cooking oils and animal fats. Additionally, one of the most promising ways to achieve long-term environmental goals is to sustainably use lignocellulosic residues. These resources must be treated through a deoxygenation process and subsequent upgrading processes to obtain high-quality road and jet biofuels. Accordingly, in this review, we explore recent advancements in the deoxygenation of oleochemical and lignocellulosic feedstocks in the absence of hydrogen to produce high-quality road and jet biofuels, mainly focusing on the use of nanomaterials as catalysts and the valorization of lipid-rich biowastes and lignocellulosic residues. As a result, we found that regardless of the catalyst particle size, the coexistence of basic sites and weak/medium acid sites is highly important in catalytic systems. Basic sites can enhance the re... [more]
Physicochemical Characterization of Santa Barbara Amorphous-15 (SBA-15) and Its Functionalization with Polyaniline for Phenol Adsorption
Lady Johana Cárdenas, Liliana Giraldo, Juan Carlos Moreno-Piraján
February 21, 2023 (v1)
Subject: Materials
Keywords: Adsorption, functionalization, immersion calorimetry, phenol, SBA-15
The chemical surface of Santa Barbara Amorphous-15 (SBA-15) was functionalized with polyaniline (SBA-15/PA) and was prepared using aniline and ammonium persulfate as the modifying agent and oxidant. The samples were characterized by N2 physical adsorption at 77 K. SBA-15’s surface area was 654.5 m2 g−1, changing to 254.6 m2 g−1. The total acidity and basicity were determined using a modified Boehm’s method, and the point of zero charge pH (pHpzc) was determined. Immersion calorimetry in water, benzene, and NaOH, HCl, and phenol (100 mg L−1) solutions was performed, producing values ranging from −15.1 to −174.1 J g−1 related to the chemical surface, pHpzc, and acid and base group values. Finally, the phenol adsorption capacity was found to be higher for the modified polyaniline silica, at 138 mg g−1.
Parameter Measurement of Edible Sunflower Exudates and Calibration of Discrete Element Simulation Parameters
Xiaoxiao Sun, Bin Li, Yang Liu, Xiaolong Gao
February 21, 2023 (v1)
Keywords: angle of repose, discrete element, edible sunflower extract, parameter calibration
To improve the accuracy of the parameters used in discrete element simulation tests in the process of clearing fresh sunflowers, this study took the extracts of fresh sunflower as the research object and used a combination of physical experiments and simulation experiments to calibrate the discrete element simulation parameters. First, the composition of the edible sunflower extract is determined, and then, the physical test method is used to determine the characteristics of the edible sunflower extract material. Based on the results of the physical test as a simulation basis, the Plackett−Burman test is used to screen the significance of the test parameters, and the screening results show that the shear modulus, static friction coefficient, and collision recovery coefficient of sunflower kernels have significant effects on the simulated angle of repose. On the basis of the steepest climbing test, the Box−Behnken test is carried out to obtain the simulated angle of repose and significa... [more]
An Investigation of Rotary Cup Burner Assembly with Three Vehicle-Mounted Cooking Stoves by Numerical Evaluation Method
Yijian Sheng, He Liu, Limo He, Jun Xiang
February 21, 2023 (v1)
Keywords: CO emissions, heating uniformity, rotary cup burner, thermal efficiency, vehicle-mounted cooking stoves
The adaptability of vehicle-mounted heating systems that include burner and stove remarkably influences the system efficiency, heat flux uniformity, and pollutants emission. In this work, the performance of a rotary cup burner assembly with three different cooking stoves was investigated using ANSYS Fluent software based on five factors of thermal efficiency, heat transfer intensity, heating uniformity, CO emissions, and flue gas outlet temperature. The Eulerian-Lagrangian method was used to perform the diesel spray, and the shear stress transfer k-ω turbulence model and the probability density function model were employed to simulate the turbulent combustion. Based on the simulation results, the performance pentagon of the above five factors was constructed to evaluate the comprehensive performance of the new rotary cup burner system. The rotary cup burner had a good performance when it is used in two staple food stoves and a subsidiary food stove. In staple food stove A, its higher f... [more]
Methods for Financial Assessment of Renewable Energy Projects: A Review
Vanderson Delapedra-Silva, Paula Ferreira, Jorge Cunha, Herbert Kimura
February 21, 2023 (v1)
Keywords: discounted cash flow, levelized cost of energy, net present value, real options, return on investment
The financial evaluation of renewable energy sources (RES) projects is well explored in the literature, but many different methods have been followed by different authors. Then, it is important to understand if and how these methods have been changing and what factors may have driven new approaches. Therefore, this article aims to explore the publications on the financial evaluation of RES projects from 2011 to 2020 and to present a critical analysis of the reviewed literature. The methods for evaluating RES projects were grouped into four categories: (i) traditional metrics based on net present value, internal rate of return, and payback period; (ii) levelized cost of electricity; (iii) return on investment approach; and (iv) real options analysis. A quantitative analysis was carried out considering aspects related to the relevance of the authors, productivity by country, and the most relevant journals for each of these groups. Then, a qualitative analysis of the main characteristics... [more]
Phytochemical Screening, Nutritional Value, Anti-Diabetic, Anti-Cancer, and Anti-Bacterial Assessment of Aqueous Extract from Abelmoschus esculentus Pods
Salman Khan, Zeeshan Rafi, Abu Baker, Ambreen Shoaib, Ali G. Alkhathami, Mohammed Asiri, Mohammad Y. Alshahrani, Irfan Ahmad, Yasser Alraey, Ali Hakamy, Mohd Saeed, Shazia Mansoor
February 21, 2023 (v1)
Subject: Biosystems
Keywords: Abelmoschus esculentus, antimicrobial activity, carotenoids, gallic acid, nutraceutical, okra, phytochemicals
Known for its high nutritional and medicinal value, okra (Abelmoschus esculentus) is commonly used for replacing plasma and expanding blood volume in humans. It is a major economic crop cultivated in tropical and subtropical regions worldwide. The present study aimed to investigate and evaluate the nutritional properties and prospective applications of the consumable parts of okra. The total ash content (mineral content), carbohydrate, crude fiber, fat, protein, and moisture fractions of okra pod aqueous extract were determined. The results show that okra aqueous extract contained 84.670−87.650% moisture, 1.514−1.197% ash, 7.857−8.261% carbohydrate, 2.367−3.410% crude protein, and 6.781−8.314% crude fiber. Okra was determined to have high nutritional value, with γ-tocopherol and α-tocopherol contents about 2.67 mg/100 g and 1.62 mg/100 g, respectively. High-performance liquid chromatography (HPLC) was performed to determine the sugars present in okra aqueous extract. The water-soluble... [more]
Cognitive Behavioral Model of an Operation Crew in the Main Control Room of a Nuclear Power Plant Based on a State-Oriented Procedure
Tao Qing, Zhaopeng Liu, Li Zhang, Yaqin Tang, Hong Hu, Shuai Chen
February 21, 2023 (v1)
Keywords: accident management, cognitive behavior, control team, nuclear power plant main control room, SOP
The team’s cognitive behavior plays a crucial role in dealing with accidents at nuclear power plants. Herein, the main behaviors of reactor operators and coordinators in performing accident management were analyzed in executing a state-oriented procedure. According to these cognitive behavioral characteristics, we established cognitive behavioral models of accident management procedures. After that, a cognitive behavioral model was established for the team in the main control room of the nuclear power plant based on the two models, which is expected to provide support to the optimization of a corresponding Human Reliability Analysis model.
Tourists’ Spatial−Temporal Behavior Patterns Analysis Based on Multi-Source Data for Smart Scenic Spots: Case Study of Zhongshan Botanical Garden, China
Jie Zheng, Xuefeng Bai, Lisha Na, Hao Wang
February 21, 2023 (v1)
Keywords: global positioning system, multi-source data, smart scenic spot, spatial–temporal behavior pattern, Zhongshan botanical garden
The data based on location/activity sensing technology is exploding and integrating multi-source data provides us with a new perspective to observe tourist behavior. On the one hand, tourist preferences can be extracted from the attractions generated by clustering. On the other hand, potentially extracted tourist information can provide decision-making support for tourism management departments in tourism planning and resource development. Therefore, developing smart tourism services for tourists and promoting the realization of “smart scenic spots.” A field survey was conducted in Zhongshan Botanical Garden, China, from 3 February to 3 April 2019. This empirical study combines a handheld GPS tracking device and questionnaire survey using SEE to optimize k-means clustering algorithm and explores the spatial−temporal behavior patterns of tourists. The results showed that tourists in the botanical garden could be divided into three behavioral patterns. They are recreation and leisure, bi... [more]
Physicochemical Properties of Starch Binary Mixtures with Cordia and Ziziphus Gums
Abdellatif Mohamed, Shahzad Hussain, Mohammed S. Alamri, Mohammed A. Ibraheem, Akram A. Abdo Qasem, Ibrahim A. Ababtain
February 21, 2023 (v1)
Subject: Materials
Keywords: Cordia, gums, pasting, rheology, starch, texture, Ziziphus
The effect of gum Cordia (GC) and gum Ziziphus (GZ) on the physicochemical properties of wheat, potato, and chickpea starches was investigated. Native or acetylated gums were mixed with starch at 2% or 5%. Starches were analyzed using rapid viscoanalyzer (RVA), differential scanning calorimeter (DSC), texture analyzer, and rheometer. In the presence of gums, the data showed clear variations between the starch gels. The effects of gum acetylation on the starch characteristics were significant. According to the starch type, the peak viscosity of the gels increased depending on the gum type or concentration. With the exception of the potato starch, when gums were added, the gelatinization temperature of the starches increased. Gum acetylation significantly increased starch−gel elasticity (high G′), particularly at the 2% concentration. GC-starch gel hardness was ranked as follows: chickpea−5% native gum > wheat−5% native gum > potato−0% gum, whereas GZ followed the order of: chickpea−2% n... [more]
The Possibility of Silicon Purification by Metallurgical Methods: Part I
Abay Serikkanov, Artem Pavlov, Bolat Mukashev, Tleuzhan Turmagambetov, Dinara Kantarbayeva, Kairat Zholdybayev
February 21, 2023 (v1)
Subject: Other
Keywords: acid leaching, elemental analysis, metallurgical grade silicon, purification, slag refining
This silicon purification research work has two stages and results will be provided in two articles due to the large scope of work. This paper provides the results of the first stage, concerning the metallurgical silicon purification. Silicon was purified by a combined method consisting of slag refining with new slag composition and acid leaching. In the first phase, the metallurgical grade silicon produced by the classical carbothermic reduction method was investigated. In the second phase, the metallurgical purification by slag refining was completed using slags of various new compositions. The purified silicon samples obtained after the melting processes were analyzed for concentrations of impurities. Finally, acid leaching treatment of the obtained silicon was done, followed by elemental analysis of purified silicon. According to our experience we can determine that obtained silicon purity is adequate for further stages of planned study.
Experimental Study of a Gas-Liquid-Solid Three-Phase Flow in an Aeration Tank Driven by an Inverted Umbrella Aerator
Siyuan Hu, Liang Dong, Runan Hua, Jinnan Guo, Houlin Liu, Cui Dai
February 21, 2023 (v1)
Subject: Other
Keywords: aeration performance, aeration tank, gas-liquid-solid three-phase flow, inverted umbrella aerator
The three-phase flow in a aeration tank driven by an inverted umbrella aerator is relatively complex, including the processes of the hydraulic jump, air entrainment, and sludge particle sedimentation. A three-phase flow test bench for an inverted umbrella aerator is established for studying its influence on aeration performance. The experiment mainly studies the changed law of aeration performance under different immersion depths or sludge concentrations and measures the flow rate and sludge concentrations in the aeration tank in different working conditions. The results are as follows. (1) The total oxygen transfer coefficient, standard oxygenation capacity, and standard power efficiency increase with the increase in rotational speed. The total oxygen transfer coefficient and standard-charge oxygen capacity first increase and then decrease with the decrease in immersion depth, reaching a maximum at −20 mm immersion depth. The standard dynamic efficiency has a similar trend and reaches... [more]
Study on Multiphase Flow in a Wide-Width Continuous Casting Mold
Lei Ren, Wenxiang Liu, Haitao Ling, Jichun Yang
February 21, 2023 (v1)
Subject: Other
Keywords: CC mold, fluid flow, multiphase flow, wide-width
The multiphase flow in the mold has a significant impact on the surface quality of the slab. In this paper, the multiphase flow in the mold is studied by establishing a one-quarter scale water mold, with the aid of a high-speed camera and particle image velocimetry (PIV). The oil phase will make the liquid surface velocity around the nozzle smaller. The greater the viscosity of the oil, the greater the critical water model casting speed and the shallower the critical immersion depth of submerged entry nozzle (SEN). Blowing will enhance the turbulence of the flow field in the mold and have a suppressing effect on the surface velocity. However, the vertical velocity of the narrow surface does not change significantly. The randomness of the bubble entering the mold from the nozzle can easily cause asymmetry of the instantaneous flow. The number of bubbles with a diameter less than 1 mm increase with the increase in gas flow rate. The larger the bubble size, the more buoyant around the noz... [more]
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