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Showing records 41676 to 41700 of 43675. [First] Page: 1664 1665 1666 1667 1668 1669 1670 1671 1672 Last
Improving Coal Flotation by Gaseous Collector Pretreatment Method and its Potential Application in Preparing Coal Water Slurry
Liang Shen, Fanfei Min, Lingyun Liu, Changguo Xue, Jinbo Zhu
October 26, 2019 (v1)
Keywords: coal water slurry, flotation, gaseous pretreatment, low-rank coal
Low-rank coal is difficult to upgrade using conventional flotation methods due to its high hydrophilic properties. Thus, it is necessary to explore new methods for upgrading and utilizing low-rank coal. In this investigation, a gaseous dodecane pretreatment method was used to enhance the flotation performance of low-rank coal. Pore distribution analysis, FTIR (Fourier Transform Infrared Spectroscopy), and contact angle measurements were used to study the surface properties of the coal sample. Size distribution and float-sink test results indicated that the coal sample contained a lot of clean coal with low ash content, which could be used as a high quality raw material for making coal water slurry. FTIR, pore distribution analysis, and contact angle results showed that the coal was very hydrophilic due to the high concentration of -OH group and the large number of pores and cracks on the coal surface. The hydrophobicity of the coal sample was significantly improved by the gaseous dodec... [more]
On the Three-Dimensional Structure of the Flow through Deterministic Lateral Displacement Devices and Its Effects on Particle Separation
Valentina Biagioni, Alessandra Adrover, Stefano Cerbelli
October 26, 2019 (v1)
Subject: Other
Keywords: deterministic ratchets, label-free separation, three-dimensional effects
Experiments have shown that a suspension of particles of different dimensions pushed through a periodic lattice of micrometric obstacles can be sorted based on particle size. This label-free separation mechanism, referred to as Deterministic Lateral Displacement (DLD), has been explained hinging on the structure of the 2D solution of the Stokes flow through the patterned geometry, thus neglecting the influence of the no-slip conditions at the top and bottom walls of the channel hosting the obstacle lattice. We show that the no-slip conditions at these surfaces trigger the onset of off-plane velocity components, which impart full three-dimensional character to the flow. The impact of the 3D flow structure on particle transport is investigated by enforcing an excluded volume approach for modelling the interaction between the finite-sized particles and the solid surfaces. We find that the combined action of particle diffusion and of the off-plane velocity component causes the suspended pa... [more]
A Modular Framework for Optimal Load Scheduling under Price-Based Demand Response Scheme in Smart Grid
Ghulam Hafeez, Noor Islam, Ammar Ali, Salman Ahmad, Muhammad Usman, Khurram Saleem Alimgeer
October 26, 2019 (v1)
Keywords: demand response, enhanced differential evolution, home energy management, hybrid gray wolf-modified enhanced differential evolutionary algorithm, load scheduling, smart grid
With the emergence of the smart grid (SG), real-time interaction is favorable for both residents and power companies in optimal load scheduling to alleviate electricity cost and peaks in demand. In this paper, a modular framework is introduced for efficient load scheduling. The proposed framework is comprised of four modules: power company module, forecaster module, home energy management controller (HEMC) module, and resident module. The forecaster module receives a demand response (DR), information (real-time pricing scheme (RTPS) and critical peak pricing scheme (CPPS)), and load from the power company module to forecast pricing signals and load. The HEMC module is based on our proposed hybrid gray wolf-modified enhanced differential evolutionary (HGWmEDE) algorithm using the output of the forecaster module to schedule the household load. Each appliance of the resident module receives the schedule from the HEMC module. In a smart home, all the appliances operate according to the sch... [more]
Pole-Zero Cancellation Method for Multi Input Multi Output (MIMO) Temperature Control in Heating Process System
Song Xu, Seiji Hashimoto, Wei Jiang
October 26, 2019 (v1)
Keywords: dead time, MIMO temperature control in heating process system, pole-zero cancelation, temperature difference, transient response
With the rapid development of industrial technology, the multi-point (multi-input multi-output) heating processing systems with integrated temperature control have been increasingly needed to achieve high-quality and high-performance processing. In this paper, in response to the demand for proper transient response and to provide more accurate temperature controls, a novel pole-zero cancelation method is proposed for multi-input multi-output (MIMO) temperature control in heating process systems. In the proposed method, the temperature differences and transient characteristics of all points can be improved by compensating dead time difference and coupling effect together by matrix compensation and pole-zero cancelation with the feedforward reference model. Both simulations and experiments were carried out. The results were compared to the well-tuned conventional PI control system and PI plus decoupling compensation system to evaluate the control efficiency of the proposed method.
Investigating the Dynamic Impact of CO2 Emissions and Economic Growth on Renewable Energy Production: Evidence from FMOLS and DOLS Tests
Muhammad Waris Ali Khan, Shrikant Krupasindhu Panigrahi, Khamis Said Nasser Almuniri, Mujeeb Iqbal Soomro, Nayyar Hussain Mirjat, Eisa Salim Alqaydi
September 30, 2019 (v1)
Subject: Energy Policy
Keywords: carbon emissions, dynamic panel cointegration model, economic growth, Energy, Fully Modified Ordinary Least Square (FMOLS), Renewable and Sustainable Energy
Understanding the dynamic nexus between CO2 emissions and economic growth in the sustainable environment helps the economies in developing resources and formulating apposite energy policies. In the recent past, various studies have explored the nexus between CO2 emissions and economic growth. This study, however, investigates the nexus between renewable energy production, CO2 emissions, and economic growth over the period from 1995 to 2016 for seven Association of Southeast Asian Nations (ASEAN) countries. Fully Modified Ordinary Least Square (FMOLS) and Dynamic Ordinary Least Square (DOLS) methodologies were used to estimate the long- and short-run relationships. The panel results revealed that renewable energy production has a significant long term effect on CO2 emissions for Vietnam (t = −2.990), Thailand (t = −2.505), and Indonesia (t = −2.515), and economic growth impact for Malaysia (t = 2.050), Thailand (t = −2.001), and the Philippines (t = −2.710). It is, therefore, vital that... [more]
Accelerating Biomanufacturing by Modeling of Continuous Bioprocessing—Piloting Case Study of Monoclonal Antibody Manufacturing
Martin Kornecki, Axel Schmidt, Lara Lohmann, Maximilian Huter, Fabian Mestmäcker, Leon Klepzig, Mourad Mouellef, Steffen Zobel-Roos, Jochen Strube
September 30, 2019 (v1)
Keywords: antibodies, continuous bioprocessing (CBP), model validation, process analytical technology (PAT), quality-by-design (QbD)
An experimental feasibility study on continuous bioprocessing in pilot-scale of 1 L/day cell supernatant, that is, about 150 g/year product (monoclonal antibody) based on CHO (Chinese hamster ovary) cells for model validation is performed for about six weeks including preparation, start-up, batch, and continuous steady-state operation for at least two weeks stable operation as well as final analysis of purity and yield. A mean product concentration of around 0.4 g/L at cell densities of 25 × 106 cells/mL was achieved. After perfusion cultivation with alternating tangential flow filtration (ATF), an aqueous two-phase extraction (ATPE) followed by ultra-/diafiltration (UF/DF) towards a final integrated counter-current chromatography (iCCC) purification with an ion exchange (IEX) and a hydrophobic interaction (HIC) column prior to lyophilization were successfully operated. In accordance to prior studies, continuous operation is stable and feasible. Efforts of broadly-qualified operation p... [more]
Economic Viability and Environmental Efficiency Analysis of Hydrogen Production Processes for the Decarbonization of Energy Systems
Li Xu, Ying Wang, Syed Ahsan Ali Shah, Hashim Zameer, Yasir Ahmed Solangi, Gordhan Das Walasai, Zafar Ali Siyal
September 30, 2019 (v1)
Keywords: economic viability, environmental efficiency, hydrogen production processes, multi-criteria analysis, Renewable and Sustainable Energy
The widespread penetration of hydrogen in mainstream energy systems requires hydrogen production processes to be economically competent and environmentally efficient. Hydrogen, if produced efficiently, can play a pivotal role in decarbonizing the global energy systems. Therefore, this study develops a framework which evaluates hydrogen production processes and quantifies deficiencies for improvement. The framework integrates slack-based data envelopment analysis (DEA), with fuzzy analytical hierarchy process (FAHP) and fuzzy technique for order of preference by similarity to ideal solution (FTOPSIS). The proposed framework is applied to prioritize the most efficient and sustainable hydrogen production in Pakistan. Eleven hydrogen production alternatives were analyzed under five criteria, including capital cost, feedstock cost, O&M cost, hydrogen production, and CO2 emission. FAHP obtained the initial weights of criteria while FTOPSIS determined the ultimate weights of criteria for each... [more]
Key Points for an Ethical Evaluation of Healthcare Big Data
Pilar Leon-Sanz
September 30, 2019 (v1)
Keywords: big data and life sciences, biomedical ethics, confidentiality, consent forms, data protection, health administration and big data
Background: The article studies specific ethical issues arising from the use of big data in Life Sciences and Healthcare. Methods: Main consensus documents, other studies, and particular cases are analyzed. Results: New concepts that emerged in five key areas for the bioethical debate on big data and health are identified—the accuracy and validity of data and algorithms, questions related to transparency and confidentiality in the use of data; aspects that raise the coding or pseudonymization and the anonymization of data, and also problems derived from the possible individual or group identification; the new ways of obtaining consent for the transfer of personal data; the relationship between big data and the responsibility of professional decision; and the commitment of the Institutions and Public Administrations. Conclusions: Good practices in the management of big data related to Life Sciences and Healthcare depend on respect for the rights of individuals, the improvement that thes... [more]
Change of Data-Driven Drug Design Trends Through Patent Analysis
Jong-Hyun Kim, Yong-Gil Lee
September 30, 2019 (v1)
Keywords: D, data science, fourth industrial revolution, innovation, patent, pharmaceutical, R&amp, technology
The pharmaceutical industry is one of the most research and development (R&D)-intensive industries. This industry has tried many strategies to overcome the limitations of a business model that had a high return and high risk. In recent years, the fourth industrial revolution has affected many industries, causing them to update their traditional production and business strategies to a “data science-based” approach. This data science methodology, based on the largely increased size of the data environment, has actively changed the pharmaceutical industry. Therefore, this study aimed to identify specific characteristics of data science innovation in the pharmaceutical industry through the analysis of patent data from the triadic patent databases from the United States, Japan, and Europe.
Flow Behavior and Hot Processing Map of GH4698 for Isothermal Compression Process
Rongchuang Chen, Haifeng Xiao, Min Wang, Jianjun Li
September 30, 2019 (v1)
Subject: Materials
Keywords: arrhenius equation, flow behavior, nickel-based alloy, processing maps
An in-depth understanding of the flow behaviors of materials deformed at high temperatures is of paramount significance. However, insufficient research on the nickel-based GH4698 alloy has resulted in inaccurate material flow prediction or even cracking in the practical billet opening of GH4698 large forgings. In this study, hot compressions were performed at 950−1150 °C and 0.001−3 s−1. Single-peaked strain-stress curves were obtained under various conditions, owing to dislocation motions in dynamic recrystallizations. The Arrhenius model was formulated to accurately describe the flow stress evolutions and the mean prediction error of the flow stress was 5.90%. Processing maps were constructed at various hot working conditions. It was found that the hot working ability of GH4698 markedly decreased under lower temperatures (950−1080 °C) and higher strain rates (0.1−3 s−1). Optimal thermal processing parameters were suggested. In sum, this study systematically investigated the flow beha... [more]
Optimal Nonlinear Adaptive Control for Voltage Source Converters via Memetic Salp Swarm Algorithm: Design and Hardware Implementation
Yueping Jiang, Xue Jin, Hui Wang, Yihao Fu, Weiliang Ge, Bo Yang, Tao Yu
September 30, 2019 (v1)
Keywords: hardware experiment, memetic salp swarm algorithm, optimal nonlinear adaptive control, perturbation observer, voltage source converter
Voltage source converter (VSC) has been extensively applied in renewable energy systems which can rapidly regulate the active and reactive power. This paper aims at developing a novel optimal nonlinear adaptive control (ONAC) scheme to control VSC in both rectifier mode and inverter mode. Firstly, the nonlinearities, parameter uncertainties, time-varying external disturbances, and unmodelled dynamics can be aggregated into a perturbation, which is then estimated by an extended state observer (ESO) called high-gain perturbation observer (HGPO) online. Moreover, the estimated perturbation will be fully compensated through state feedback. Besides, the observer gains and controller gains are optimally tuned by a recent emerging biology-based memetic salp swarm algorithm (MSSA), the utilization of such method can ensure a desirably satisfactory control performance. The advantage of ONAC is that even though the operation conditions are constantly changing, the control performance can still b... [more]
Extraction Process of Polyphenols from Soybean (Glycine max L.) Sprouts: Optimization and Evaluation of Antioxidant Activity
Xuan Tien Le, Vo Luu Lan Vi, Tran Quoc Toan, Long Giang Bach, Tran Thanh Truc, Pham Thi Hai Ha
September 30, 2019 (v1)
Subject: Biosystems
Keywords: antioxidant activity, isoflavone, Optimization, soybean sprout, total polyphenol content
This research aimed to optimize the total polyphenol content (TPC) extracted from soybean sprout powder under different experimental parameters, including ethanol concentration (60−100% v/v), extraction temperature (40−80 °C), extraction time (15−150 min), material:solvent ratio (1:4−1:10 g/mL), the number extraction cycles (1, 2 and 3 times), the age of sprout (0−7 days), and the used part of the sprout (cotyledon, hypocotyl, or radicle). The obtained results were used in response surface methodology, in combination with a central composite design, to model the total polyphenol content (TPC) with respect to three variables, including ethanol concentration, extraction temperature, and material:solvent ratio. The experimental conditions for optimal recovery of TPC consisted of ethanol concentration of 88% (v/v), extraction temperature of 59 °C, material:solvent ratio of 1:6.5 g/mL, extraction time of 60 min, and 2 cycles of maceration. In addition, for maximal TPC, the sprout should und... [more]
Ultrasound-Assisted Extraction of Pectin from Malus domestica ‘Fălticeni’ Apple Pomace
Florina Dranca, Mircea Oroian
September 30, 2019 (v1)
Subject: Biosystems
Keywords: apple pomace, Malus domestica ‘Fălticeni’, Optimization, pectin, ultrasound
The use of an ultrasonic treatment for the extraction of pectin from Malus domestica ‘Fălticeni’ apple pomace, its effects on extraction yield and galacturonic acid content, and degree of esterification of the extracted pectin were investigated. The optimization of the extraction process showed that the highest yield of 9.183% pectin, with a 98.127 g/100 g galacturonic acid content and 83.202% degree of esterification, was obtained at 100% amplitude, pH of 1.8, SLR of 1:10 g/mL, and 30 min. The pectin obtained in optimal extraction conditions was compared to commercial citrus and apple pectin in terms of chemical composition (determined by FT-IR), thermal behaviour (analyzed by differential scanning calorimetry), rheological properties, and morphological structure (analyzed by scanning electron microscopy). By comparison to commercial citrus and apple pectin samples, the FT-IR analysis of pectin extracted by ultrasound treatment confirmed the high degree of esterification and showed si... [more]
Applying a Watershed and Reservoir Model in an Off-Site Reservoir to Establish an Effective Watershed Management Plan
Chi-Feng Chen, Yi-Ru Wu, Jen-Yang Lin
September 30, 2019 (v1)
Keywords: eutrophication, off-site reservoir, storm water management model (SWMM), watershed water quality model
Off-site reservoirs use water from other watersheds to supplement their water quantity. Water quality is usually better in off-site reservoirs than in onsite reservoirs, because in comparison to onsite reservoirs, watershed areas are smaller and fewer pollutants are collected; moreover, cleaner water is introduced. However, in Taiwan, the water quality of some off-site reservoirs can gradually worsen, and this factor needs to be addressed. In this study, the Liyutan reservoir in central Taiwan was used as an example to demonstrate the process of evaluating pollution in an off-site reservoir. Pollution loads from point sources (PSs) and nonpoint sources (NPSs) were carefully estimated. Domestic sewage and tourist wastewater were considered the major PS loads in this study. The NPS load evaluation was dependent on the results of a verified watershed model, the stormwater management model (SWMM). The observed data in 2015 and 2016 and supplementary total phosphorous (TP) samplings in upst... [more]
Experimental Study on Precipitation Behavior of Spinels in Stainless Steel-Making Slag under Heating Treatment
Jianli Li, Qiqiang Mou, Qiang Zeng, Yue Yu
September 30, 2019 (v1)
Subject: Materials
Keywords: Cr2O3, crystal size, heating time, spinel, stainless steel slag
The stability of chromium in stainless steel slag has a positive correlation with spinel particle size and a negative correlation with the calcium content of the spinel. The effect of heating time on the precipitation of spinel crystals in the CaO-SiO2-MgO-Al2O3-Cr2O3-FeO system was investigated in the laboratory. Scanning electron microscopy with energy-dispersive and X-ray diffraction were adopted to observe the microstructure, test the chemical composition, and determine the mineral phases of synthetic slags, and FactSage7.1 was applied to calculate the crystallization process of the molten slag. The results showed that the particle size of the spinel crystals increased from 9.42 to 10.73 μm, the calcium content in the spinel crystals decreased from 1.38 at% to 0.78 at%, and the content of chromium in the spinel crystal increased from 16.55 at% to 22.78 at% with an increase in the heating time from 0 min to 120 min at 1450 °C. Furthermore, the species of spinel minerals remained con... [more]
Numerical and Analytical Investigation of an Unsteady Thin Film Nanofluid Flow over an Angular Surface
Haroon Ur Rasheed, Zeeshan Khan, Ilyas Khan, Dennis Ling Chuan Ching, Kottakkaran Sooppy Nisar
September 30, 2019 (v1)
Keywords: angular surface, nanofluid, numerical and analytical solutions, thin-film flow, unsteady flow
In the present study, we examine three-dimensional thin film flow over an angular rotating disk plane in the presence of nanoparticles. The governing basic equations are transformed into ordinary differential equations by using similarity variables. The series solution has been obtained by the homotopy asymptotic method (HAM) for axial velocity, radial velocity, darning flow, induced flow, and temperature and concentration profiles. For the sake of accuracy, the results are also clarified numerically with the help of the BVPh2- midpoint method. The effect of embedded parameters such as the Brownian motion parameter Nb, Schmidt number Sc, thermophoretic parameter and Prandtl number Pr are explored on velocity, temperature and concentration profiles. It is observed that with the increase in the unsteadiness factor S, the thickness of the momentum boundary layer increases, while the Sherwood number Sc, with the association of heat flow from sheet to fluid, reduces with the rise in S and r... [more]
Optimization of Microwave-Assisted Extraction of Total Phenolic and Total Flavonoid Contents from Fruits of Docynia indica (Wall.) Decne. Using Response Surface Methodology
Xuan Duy Le, Manh Cuong Nguyen, Dinh Hoang Vu, Minh Quan Pham, Quoc Long Pham, Quang Tung Nguyen, Tuan Anh Nguyen, Van Thinh Pham, Long Giang Bach, Tuong Van Nguyen, Quoc Toan Tran
September 30, 2019 (v1)
Subject: Biosystems
Keywords: Docynia indica, microwave-assisted extraction, response surface methodology, total phenolic content and total flavonoid content
Docynia indica (D. indica) shows various useful biological activities, such as antioxidant, anti-inflammatory, antibacterial effects, and positive benefits for human health. Such biological activities relate to the main phytochemicals of D. indica including phenolic and flavonoid. However, isolation for phenolic and flavonoid by popular methods such as hot extraction, soxhlet extraction, and ultrasonic extraction have been relatively ineffective. Therefore, in this study, microwave-assisted extraction (MAE) was used for the extraction of total phenolic and total flavonoid from D. indica. The optimization experiments were conducted based on response surface methodology (RMS) according to a central composite design with four independent variables: extraction time (min), ethanol concentration (%, v/v), microwave power (W), and pH of the solvent. Three dependent variables were total phenolic content (TPC), total flavonoid content (TFC), and yield. The optimal conditions for the extraction... [more]
Optimal Allocation of Energy Storage System Considering Price-Based Demand Response and Dynamic Characteristics of VRB in Wind-PV-ES Hybrid Microgrid
Qingwu Gong, Jintao Fang, Hui Qiao, Dong Liu, Si Tan, Haojie Zhang, Haitao He
September 30, 2019 (v1)
Keywords: demand response, dynamic characteristics of batteries, improved particle swarm optimization, optimal allocation
Studying the influence of the demand response and dynamic characteristics of the battery energy storage on the configuration and optimal operation of battery energy storage system (BESS) in the Wind-Photovoltaic (PV)-Energy Storage (ES) hybrid microgrid. A demand response model that is based on electricity price elasticity is established based on the time-of-use price. Take the capital-operating cost and direct economic benefit of the BESS and the loss of abandoned photovoltaic and wind power as the optimization objective, an optimal configuration method that considers the dynamic characteristics of the BESS and the maximum absorption of photovoltaic and wind power is proposed while using particle swarm optimization to solve. The results show that the configuration results considering the demand side response of the microgrid BESS can obtain better economy and reduce the storage capacity requirement, and the result shows that the efficiency of BESS relates to the load of the system, th... [more]
The Effect of Extraction Methods on Preliminary Structural Properties and Antioxidant Activities of Polysaccharides from Lactarius vividus
Zhou Xu, Shiling Feng, Jipeng Qu, Ming Yuan, Ruiwu Yang, Lijun Zhou, Tao Chen, Chunbang Ding
September 30, 2019 (v1)
Subject: Biosystems
Keywords: antioxidant activities, extraction methods, Lactarius vividus, polysaccharides, preliminary structure properties
Four polysaccharides (LVP-u, LVP-m, LVP-e, and LVP-h) were extracted from the fruiting bodies of Lactarius vividus by an ultrasonic-assisted extraction method, microwave-assisted extraction method, enzyme-assisted extraction method, and hot water extraction method, respectively. Then, the effect of extraction methods on yields, preliminary structural properties, and antioxidant activities was systematically investigated using the weighing method, chemical composition analysis, high-performance gel permeation chromatography (HPGPC), high-performance liquid chromatography (HPLC), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), radical scavenging, and metal ion chelating assays. Results demonstrated that the four L. vividus polysaccharides (LVPs) were all combined with protein, and the yield of LVP-u was higher than others. Molecular weight distribution, monosaccharide and amino acid compositions, and microstructures among the four LVPs were significan... [more]
Maintenance Optimization Model with Sequential Inspection Based on Real-Time Reliability Evaluation for Long-Term Storage Systems
Senyang Bai, Zhijun Cheng, Bo Guo
September 30, 2019 (v1)
Keywords: long-term storage system, preventive maintenance, real-time reliability, sequential inspection, Wiener process
For long-term storage systems such as rockets and missiles, most of the relevant models and algorithms for inspection and maintenance currently focus on analysis based on periodic inspection. However, considering factors such as the complexity of the degradation mechanisms of these systems, the constraints imposed by failure risk, and the uncertainty caused by environmental factors, it is preferable to dynamically determine the inspection intervals based on real-time status information. This paper investigates the issue of maintenance optimization modelling for long-term storage systems based on real-time reliability evaluation. First, the Wiener process is used to establish a performance degradation model for one critical unit of such a system, and a closed-form expression for the real-time reliability distribution is obtained by using the first-hitting-time theory. Second, sequential inspection intervals are dynamically determined by combining the real-time reliability function with... [more]
A Method and Device for Detecting the Number of Magnetic Nanoparticles Based on Weak Magnetic Signal
Li Wang, Tong Zhou, Qunfeng Niu, Yanbo Hui, Zhiwei Hou
September 30, 2019 (v1)
Keywords: Genetic Algorithm, magnetic nanoparticles, number detection, Simulated Annealing Neural Network, weak magnetic signal
In recent years, magnetic nanoparticles (MNPs) have been widely used as a new material in biomedicine and other fields due to their broad versatility, and the quantitative detection method of MNPs is significantly important due to its advantages in immunoassay and single-molecule detection. In this study, a method and device for detecting the number of MNPs based on weak magnetic signal were proposed and machine learning methods were applied to the design of MNPs number detection method and optimization of detection device. Genetic Algorithm was used to optimize the MNPs detection platform and Simulated Annealing Neural Network was used to explore the relationship between different positions of magnetic signals and the number of MNPs so as to obtain the optimal measurement position of MNPs. Finally, Radial Basis Function Neural Network, Simulated Annealing Neural Network, and partial least squares multivariate regression analysis were used to establish the MNPs number detection model,... [more]
Physical Simulation of Molten Steel Homogenization and Slag Entrapment in Argon Blown Ladle
Fu Yang, Yan Jin, Chengyi Zhu, Xiaosen Dong, Peng Lin, Changgui Cheng, Yang Li, Lin Sun, Jianhui Pan, Qiang Cai
September 30, 2019 (v1)
Keywords: mixing time, secondary refining, slag entrapment, water model
Argon stirring is one of the most widely used metallurgical methods in the secondary refining process as it is economical and easy, and also an important refining method in clean steel production. Aiming at the issue of poor homogeneity of composition and temperature of a bottom argon blowing ladle molten steel in a Chinese steel mill, a 1:5 water model for 110 t ladle was established, and the mixing time and interface slag entrainment under the different conditions of injection modes, flow rates and top slag thicknesses were investigated. The flow dynamics of argon plume in steel ladle was also discussed. The results show that, as the bottom blowing argon flow rate increases, the mixing time of ladle decreases; the depth of slag entrapment increases with the argon flow rate and slag thickness; the area of slag eyes decreases with the decrease of the argon flow rate and increase of slag thickness. The optimum argon flow rate is between 36−42 m3/h, and the double porous plugs injection... [more]
Evaluation for the Leaching of Cr from Coal Gangue Using Expansive Soils
Yan Zhang, Hassan Baaj, Rong Zhao
September 30, 2019 (v1)
Subject: Energy Policy
Keywords: coal gangue, expansive soil, heavy metal, leaching, unconfined compressive strength
Coal gangue can cause significant heavy metal pollution in mining areas, which would have a negative impact on the environment and human health. The objective of this research is to investigate the relationship between expansive soil amount and the leaching behavior of Chromium from coal gangue and the engineering properties of coal gangue used as building materials. The leaching behavior of Chromium from coal gangue was observed using atomic absorption spectrometry. A column leaching experiment was conducted to examine the impact of leaching time and heavy metal concentration. Furthermore, the unconfined compressive strength test was employed to evaluate the engineering properties of coal gangue with expansive soil. The results of the study demonstrate that pH of leachate solutions, leaching time, and expansive soil amounts in mixtures have important influence on Chromium concentration. The leachate solutions, which behave like alkaline, provide a positive environment for adsorbing Cr... [more]
Integrated Component Optimization and Energy Management for Plug-In Hybrid Electric Buses
Xiaodong Liu, Jian Ma, Xuan Zhao, Yixi Zhang, Kai Zhang, Yilin He
September 30, 2019 (v1)
Keywords: energy management, model-free adaptive control, NSGA-II, Optimization, plug-in hybrid electric vehicle, real-time
The complicated coupling of component design together with energy management has brought a significant challenge to the design, optimization, and control of plug-in hybrid electric buses (PHEBs). This paper proposes an integrated optimization methodology to ensure the optimum performance of a PHEB with a view toward designing and applications. First, a novel co-optimization method is proposed for redesigning the driveline parameters offline, which combines a nondominated sorting genetic algorithm-II (NSGA-II) with dynamic programming to eliminate the impact of the coupling between the component design and energy management. Within the new method, the driveline parameters are optimally designed based on a global optimal energy management strategy, and fuel consumption and acceleration time can be respectively reduced by 4.71% and 4.59%. Second, a model-free adaptive control (MFAC) method is employed to realize the online optimal control of energy management on the basis of Pontryagin’s... [more]
Recombinant Proteins for Industrial versus Pharmaceutical Purposes: A Review of Process and Pricing
John Puetz, Florian M. Wurm
September 30, 2019 (v1)
Subject: Biosystems
Keywords: drug preparation, manufactured materials, price, recombinant proteins
Recombinant proteins have been produced for over 30 years. Applications range from enzymes used in laundry detergents to antigen-detecting antibodies in cancer therapy. Despite similarities in manufacturing, drastic differences in retail pricing between recombinant proteins used for industrial (non-medical) versus pharmaceutical purposes exist. Industrial proteins often have a retail price in the tens of dollars per kilogram while recombinant proteins for medical use may cost billions of dollars per kilogram. This manuscript will briefly review manufacturing techniques and contrast the differences between industrial versus pharmaceutical production. Maximizing manufacturing technologies to reduce cost-of-goods (CoG) is desirable. However, the major reason for the very high pricing of pharma protein products does not reflect CoG, but the financial obligations of clinical trials, research and development, patent constraints, marketing, and return on investment.
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