Records Added in 2020
Records added in 2020
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Showing records 1239 to 1263 of 1263. [First] Page: 1 47 48 49 50 51 Last
Marine Algae: A Potential Resource of Anti-HSV Molecules
Mohamad Fawzi Mahomoodally, Devina Lobine, Kannan R. R. Rengasamy, Shanmugaraj Gowrishankar, Devesh Tewari, Gokhan Zengin, Doo Hwan Kim, Iyyakkannu Sivanesan
January 2, 2020 (v1)
Subject: Biosystems
Keywords: antiviral, brown algae, green algae, Herpesviridae, human infections, natural product, phytochemicals, red algae, sulfated polysaccharides, virus
Herpes simplex viruses (HSVs) are common human pathogens belonging to the subfamily alpha-herpesvirinae that trigger severe infections in neonates and immunocompromised patients. After primary infection, the HSVs establish a lifelong latent infection in the vegetative neural ganglia of their hosts. HSV infections contribute to substantial disease burden in humans as well as in newborns. Despite a fair number of drugs being available for the treatment of HSV infections, new, effective, and safe antiviral agents, exerting different mechanisms of action, are urgently required, mainly due to the increasing number of resistant strains. Accumulating pieces of evidence have suggested that structurally diverse compounds from marine algae possess promising anti-HSV potentials. Several studies have documented a variety of algal polysaccharides possessing anti-HSV activity, including carrageenan and fucan. This review aimed to compile previous anti-HSV studies on marine algae−derived compounds, e... [more]
Transport and Deposition of Large Aspect Ratio Prolate and Oblate Spheroidal Nanoparticles in Cross Flow
Hans O. Åkerstedt
January 2, 2020 (v1)
Keywords: boundary layers, composite manufacturing, cross flow, deposition, non-spherical particles, Stokes flow, transport
The objective of this paper was to study the transport and deposition of non-spherical oblate and prolate shaped particles for the flow in a tube with a radial suction velocity field, with an application to experiments related to composite manufacturing. The transport of the non- spherical particles is governed by a convective diffusion equation for the probability density function, also called the Fokker−Planck equation, which is a function of the position and orientation angles. The flow is governed by the Stokes equation with an additional radial flow field. The concentration of particles is assumed to be dilute. In the solution of the Fokker−Planck equation, an expansion for small rotational Peclet numbers and large translational Peclet numbers is considered. The solution can be divided into an outer region and two boundary layer regions. The outer boundary layer region is governed by an angle-averaged convective-diffusion equation. The solution in the innermost boundary layer regi... [more]
CoFe2O4 Nanomaterials: Effect of Annealing Temperature on Characterization, Magnetic, Photocatalytic, and Photo-Fenton Properties
Nguyen Thi To Loan, Nguyen Thi Hien Lan, Nguyen Thi Thuy Hang, Nguyen Quang Hai, Duong Thi Tu Anh, Vu Thi Hau, Lam Van Tan, Thuan Van Tran
January 2, 2020 (v1)
Subject: Materials
Keywords: cobalt ferrite, magnetic properties, photocatalytic activity, rhodamine B, solution combustion method
In this research, structural, magnetic properties and photocatalytic activity of cobalt ferrite spinel (CoFe2O4) nanoparticles were studied. The samples were characterized by X-ray powder diffraction (XRD), energy dispersive X-ray (EDX), scanning electron microscopy (SEM), transmission electronic microscopy (TEM), Brunauer−Emmett−Teller (BET), Fourier transform infrared spectroscopy (FTIR), and UV-visible diffused reflectance spectroscopy (DRS) analysis. The XRD analysis revealed the formation of the single-phase CoFe2O4 with a cubic structure that is annealed at 500−700 °C in 3 h. The optical band gap energy for CoFe2O4 was determined to be in the range of 1.57−2.03 eV. The effect on the magnetic properties of cobalt ferrites was analyzed by using a vibrating sample magnetometer (VSM). The particle size and the saturation magnetization of cobalt ferrite nanoparticles increased with increasing annealing temperature. The photocatalytic activity of CoFe2O4 nanoparticles was investigated... [more]
A Numerical Study on Influent Flow Rate Variations in a Secondary Settling Tank
Junwei Su, Le Wang, Yumin Zhang, Zhaolin Gu
January 2, 2020 (v1)
Keywords: Computational Fluid Dynamics, numerical simulation, secondary settling tank, solid–liquid two-phase flow
The secondary settling tank is an essential unit for the biochemical treatment of domestic sewage, and its operational effect influences the quality of effluent. Under the influence of the confluence of rainwater and sewage, wastewater use habits, etc., the inflow of the secondary sedimentation tank changes over time. In this paper, OpenFOAM, an open-source computational fluid dynamics package, was used to study the dynamic behaviors of solid−liquid two-phase flow in the tank under influent flow rate variations. A coupled method including a mixture model, drift equation and a dynamic boundary method is proposed. Numerical investigations were carried out for a 2D axisymmetric sedimentation tank using 12 cases. With increasing influent flow rate, sludge accumulates continuously in the bottom left side of the tank, sludge hopper, and inlet; the sludge blanket thickness near the right end of the tank increases continuously; and the sludge concentration in the tank approximately linearly in... [more]
CFD Applications in Energy Engineering Research and Simulation: An Introduction to Published Reviews
Alfredo Iranzo
January 2, 2020 (v1)
Keywords: combustion, Computational Fluid Dynamics, energy engineering, heat transfer, Modelling, Renewable and Sustainable Energy, Simulation, thermal radiation, turbulence
Computational Fluid Dynamics (CFD) has been firmly established as a fundamental discipline to advancing research on energy engineering. The major progresses achieved during the last two decades both on software modelling capabilities and hardware computing power have resulted in considerable and widespread CFD interest among scientist and engineers. Numerical modelling and simulation developments are increasingly contributing to the current state of the art in many energy engineering aspects, such as power generation, combustion, wind energy, concentrated solar power, hydro power, gas and steam turbines, fuel cells, and many others. This review intends to provide an overview of the CFD applications in energy and thermal engineering, as a presentation and background for the Special Issue “CFD Applications in Energy Engineering Research and Simulation” published by Processes in 2020. A brief introduction to the most significant reviews that have been published on the particular topics is... [more]
Systematic Selection of Green Solvents and Process Optimization for the Hydroformylation of Long-Chain Olefines
Tobias Keßler, Christian Kunde, Steffen Linke, Kevin McBride, Kai Sundmacher, Achim Kienle
January 2, 2020 (v1)
Keywords: BARON, green solvents, hydroformylation, process optimization, TMS
Including ecologic and environmental aspects in chemical engineering requires new methods for process design and optimization. In this work, a hydroformylation process of long-chain olefines is investigated. A thermomorphic multiphase system is employed that is homogeneous at reaction conditions and biphasic at lower temperatures for catalyst recycling. In an attempt to replace the toxic polar solvent N,N-dimethylformamide (DMF), ecologically benign alternatives are selected using a screening approach. Economic process optimization is conducted for DMF and two candidate solvents. It is found that one of the green candidates performs similarly well as the standard benchmark solvent DMF, without being toxic. Therefore, the candidate has the potential to replace it.
Splitting Triglycerides with a Counter-Current Liquid−Liquid Spray Column: Modeling, Global Sensitivity Analysis, Parameter Estimation and Optimization
Mark Nicholas Jones, Hector Forero-Hernandez, Alexandr Zubov, Bent Sarup, Gürkan Sin
January 2, 2020 (v1)
Keywords: hydrolysis, Modelling, Optimization, parameter estimation, sensitivity analysis, spray column, vegetable oil
In this work we present the model of a counter-current spray column in which a triglyceride (tripalmitic triglyceride) is hydrolyzed by water and leads to fatty acid (palmitic acid) and glycerol. A finite volume model (FVM) of the column was developed to describe the reactive extraction process with a two-phase system and validated with an analytical model from the literature with the given data set encompassing six experimental runs. Global, variance-based (Sobol) sensitivity analysis allowed assessment of the sensitivity of the sweet water glycerol content in respect to liquid density, overall mass-transfer coefficient, reaction rate coefficient and the equilibrium ratio to rank them accordingly. Furthermore, parameter estimation with a differential evolution (DE) algorithm was performed to obtain among others the mass transfer, backmixing and reaction rate coefficients. The model was used to formulate and solve a process design problem regarding economic and sustainable performance.... [more]
CFD Simulation on Hydrodynamic Behaviors of Anaerobic Granule Swarms
Xiuqin Dong, Sheng Wang, Zhongfeng Geng
January 2, 2020 (v1)
Keywords: anaerobic granule swarm, Computational Fluid Dynamics, drag force coefficient, Reynolds number, voidage
An internal circulation (IC) anaerobic reactor is widely used in the treatment of municipal and industrial wastewater with high volumetric loading rates. The performance of an IC reactor is closely related with hydrodynamic behaviors of anaerobic granules. Typically, anaerobic granules work in swarms and the settling behavior of a granule is disturbed by other granules. However, the research on anaerobic granule swarms is insufficient. In this work, Computational Fluid Dynamics (CFD) method was employed to study the hydrodynamic behaviors of anaerobic granule swarms with various voidages. The simulated results showed that the average velocity inside granules increased significantly as the voidage of granule swarm decreased and as the Reynolds number increased. The maximum shear stress on the granule’s surface increased with decreasing voidage and increasing Reynolds number. Based on the hydrodynamic behaviors of anaerobic granule swarms, an improved model of drag force coefficient for... [more]
Performance and Microbial Community Structure of Anaerobic Membrane Bioreactor for Lipids-Rich Kitchen Waste Slurry Treatment: Mesophilic and Thermophilic Processes
Xiaolan Xiao, Wansheng Shi, Wenquan Ruan
January 2, 2020 (v1)
Subject: Biosystems
Keywords: anaerobic microorganism, digestion performance, high lipids wastewater, long chain fatty acid, membrane filtration
The performance and microbial community structure for treating lipids-rich kitchen waste slurry in mesophilic Anaerobic Membrane Bioreactor (m-AnMBR) and thermophilic AnMBR (t-AnMBR) were compared in this study. Higher Organic Loading Rate (OLR) of 12 kg-COD/(m3·d), better Chemical Oxygen Demand (COD) removal efficiency over 98%, stronger stability with Volatile Fatty Acids (VFAs)/alkalinity below 0.04, higher flux with 18 L/(m2·h) and lower Long Chain Fatty Acids (LCFAs) concentration of 550 mg/L were obtained in the m-AnMBR. Directly increasing temperature from 39 to 55 °C resulted in a collapse of the t-AnMBR. Acclimation via gradually increasing temperature made the t-AnMBR run successfully with lower OLR and COD removal efficiency of 7.5 kg-COD/(m3·d) and 96%. An obvious discrepancy of microbial community structure was presented between the m-AnMBR and t-AnMBR via the 16S rRNA gene sequence analysis. The Methanomethylovorans and Methanoculleus were dominant in the t-AnMBR instead... [more]
Antioxidant Activity and Selenium and Polyphenols Content from Selected Medicinal Plants Natives from Various Areas Abundant in Selenium (Poland, Lithuania, and Western Ukraine)
Zofia Sotek, Bożenna Białecka, Bogumiła Pilarczyk, Radosław Drozd, Renata Pilarczyk, Agnieszka Tomza-Marciniak, Barna Kruzhel, Halyna Lysak, Małgorzata Bąkowska, Stakh Vovk
January 2, 2020 (v1)
Subject: Biosystems
Keywords: ABTS, FRAP, herbs, polyphenols, selenium
The study was performed on Centaurea cyanus, Chamomilla recutita, Majorana hortensis, Ocimum basilicum, Plantago lanceolata, Sinapis alba, and Valeriana officinalis harvested in Lithuania, Poland, and Ukraine. Our aim was to determine the differences in selenium concentrations, total polyphenols, and the antioxidant activity in same-species samples from different regions. Another goal was to assess the correlations between these variables within the species. We found variations in most species, but not in all regions of harvesting. In four of the six species from Ukraine, we observed the highest concentration of Se. The selenium concentrations ranged from 15−182 µg/kg DW, and the greatest variation between the regions occurred in S. alba. The level of polyphenols was 5.52−53.25 mg TAE/100 g DW, and the largest differences between the sampling regions occurred in P. lanceolata and O. basilicum. ABTS radicals scavenging ability ranged from 5.20−59.79 μM AAE/100 g DW, while the FRAP poten... [more]
Lattice Boltzmann Simulation on Droplet Flow through 3D Metal Foam
Jian Zhang, Xinhai Yu, Shan-Tung Tu
January 2, 2020 (v1)
Keywords: droplet break, lattice Boltzmann method, metal foam, multiphase flow
The hydrodynamics of droplets passing through metal foam is investigated using the lattice Boltzmann method (LBM). The accurate 3D porous structure for the simulation is generated by X-ray micro-computed tomography. The simulated results are in good agreement with the experimental ones using high-speed video. The simulated results show that for droplets passing metal foam, there is a critical capillary number, Cac (around 0.061), above which the droplet continues to deform until it breaks up. The simulated results show that the capillary number, droplet size, pores diameter, and thickness of metal foam have the significant effect of droplets deforming and breaking up when the droplets pass through the metal foam. To avoid the calescence of two droplets at the inlet zone of the metal foam, the distance between droplets should be larger than three times the diameter of the droplet.
Effect of Pre-Combustion Chamber Nozzle Parameters on the Performance of a Marine 2-Stroke Dual Fuel Engine
Hao Guo, Song Zhou, Majed Shreka, Yongming Feng
January 2, 2020 (v1)
Keywords: Computational Fluid Dynamics, dual-fuel engine, pre-combustion chamber, Simulation, two-stroke
In recent years and with the increasing rigor of the International Maritime Organization (IMO) emission regulations, the shipping industry has focused more on environment-friendly and efficient power. Low-pressure dual-fuel (LP-DF) engine technology with high efficiency and good emissions has become a promising solution in the development of marine engines. This engine often uses pre-combustion chamber (PCC) to ignite natural gas due to its higher ignition energy. In this paper, a parametric study of the LP-DF engine was proceeded to investigate the design scheme of the PCC. The effect of PCC parameters on engine performance and emissions were studied from two aspects: PCC nozzle diameter and PCC nozzle angle. The results showed that the PCC nozzle diameter affected the propagation of the flame in the combustion chamber. Moreover, suitable PCC nozzle diameters helped to improve flame propagation stability and engine performance and reduce emissions. Furthermore, the angle of the PCC no... [more]
Recovery of Protein from Dairy Milk Waste Product Using Alcohol-Salt Liquid Biphasic Flotation
Pei En Tham, Yan Jer Ng, Revathy Sankaran, Kuan Shiong Khoo, Kit Wayne Chew, Yee Jiun Yap, Masnindah Malahubban, Fitri Abdul Aziz Zakry, Pau Loke Show
January 2, 2020 (v1)
Keywords: dairy waste, liquid biphasic flotation, milk, protein, recovery
Expired dairy products are often disposed of due to the potential health hazard they pose to living organisms. Lack of methods to recover valuable components from them are also a reason for manufactures to dispose of the expired dairy products. Milk encompasses several different components with their own functional properties that can be applied in production of food and non-food technical products. This study aims to investigate the novel approach of using liquid biphasic flotation (LBF) method for protein extraction from expired milk products and obtaining the optimal operating conditions for protein extraction. The optimized conditions were found at 80% concentration ethanol as top phase, 150 g/L dipotassium hydrogen phosphate along with 10% (w/v) milk as bottom phase, and a flotation time of 7.5 min. The protein recovery yield and separation efficiency after optimization were 94.97% and 86.289%, respectively. The experiment has been scaled up by 40 times to ensure it can be commerc... [more]
Fretting Wear in Orthodontic and Prosthetic Alloys with Ti(C, N) Coatings
Katarzyna Banaszek, Leszek Klimek, Jan Ryszard Dąbrowski, Wojciech Jastrzębski
January 2, 2020 (v1)
Subject: Materials
Keywords: dental alloys, fretting, fretting wear, Ni-Cr-Mo, Ti(C, N) coating, titaniumcarbonitride
Fretting occurs during orthodontic treatment or wearing prosthesis. Although weight of particles is marginal, the total releasing area is more of a concern due to amount and volume of molecules. The aim of the study was to examine the fretting wear resistance of orthodontic and prosthetic alloy Ni-Cr-Mo samples coated with Ti(C, N) and to compare them with samples without any coating. Five groups of cylindrical shape samples (S1−S5) made of Ni-Cr-Mo were coated with Ti(C, N) layers with different content of C and N. The control group (S0) was without layer. The alloys underwent fretting wear resistance tests with amplitude 100 μm, at frequency 0.8 Hz with averaged unit load: 5, 10, and 15 N for 15 min. The samples were subjected to microscopic observations using scanning electron microscope and a laser scanning microscope. Samples with Ti(C, N) coatings revealed higher fretting wear resistance. The wear in each case with Ti(C, N) coatings was over twice as low. The lowest wear and thus... [more]
Performance Assessment of a Hybrid Vapor Compression and Evaporative Cooling Fresh-Air-Handling Unit Operating in Hot Climates
Yousef Al Horr, Bourhan Tashtoush, Nelson Chilengwe, Mohamed Musthafa
January 2, 2020 (v1)
Keywords: cooling performance, energy savings, hot and humid climate, indirect evaporative cooling, mode of operation
Evaporative cooling can be integrated into fresh-air-handling units, to reduce cooling demand. This study considers a hybrid fresh-air-handling unit which incorporates a vapor-compression cooling cycle and indirect evaporative cooling to condition an ambient primary airstream to a desired supply air state. The cooling effects of using various modes (vapor compression only; direct expansion with mist; direct expansion with water shower; and direct expansion with mist and water shower) are compared when the fresh-air-handling unit operates in harsh (hot and humid) climatic conditions experienced in Qatar. Experimental analysis is based on actual ambient conditions measured from August 2018 to July 2019. It is found that the best-performing wet mode of operation saves more than 60% of the energy required by a conventional direct expansion cooling system operating under the same ambient conditions. In hot, dry conditions, the coefficient of performance of the fresh-air-handling unit when u... [more]
Controlled Synthesis of Triangular Silver Nanoplates by Gelatin−Chitosan Mixture and the Influence of Their Shape on Antibacterial Activity
Quoc Khuong Vo, Duc Duy Phung, Quynh Nhu Vo Nguyen, Hong Hoang Thi, Nhat Hang Nguyen Thi, Phuong Phong Nguyen Thi, Long Giang Bach, Lam Van Tan
January 2, 2020 (v1)
Subject: Materials
Keywords: antibacterial activity, gelatin, seeding growth approach, triangular silver nanoplates
Triangular silver nanoplates were prepared by using the seeding growth approach with the presence of citrate-stabilized silver seeds and a mixture of gelatin−chitosan as the protecting agent. By understanding the critical role of reaction components, the synthesis process was improved to prepare the triangular nanoplates with high yield and efficiency. Different morphologies of silver nanostructures, such as triangular nanoplates, hexagonal nanoprisms, or nanodisks, can be obtained by changing experimental parameters, including precursor AgNO3 volume, gelatin−chitosan concentration ratios, and the pH conditions. The edge lengths of triangular silver nanoplates were successfully controlled, primarily through the addition of silver nitrate under appropriate condition. As-prepared triangular silver nanoplates were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), UV-Vis, Fourier transform infrared spectroscopy (FT-IR), and X-Ray diffraction (XRD). Si... [more]
Application of an In Vitro Psoriatic Skin Model to Study Cutaneous Metabolization of Tazarotene
Alexandre Morin, Mélissa Simard, Geneviève Rioux, Alexe Grenier, Sophie Morin, Roxane Pouliot
January 2, 2020 (v1)
Subject: Biosystems
Keywords: 3D culture, metabolization, psoriasis, skin substitutes, tazarotene, tissue engineering
Psoriasis is an inflammatory skin disease characterized by the presence of whitish and scaly plaques, which can cover up to 90% of the body surface. These plaques result from the hyperproliferation and abnormal differentiation of keratinocytes. Dermopharmaceutical testing of new therapies is limited by healthy and pathological skin models, which are not closely enough mimicking their in vivo counterparts. In this study, we exploited percutaneous absorption and Ultra Performance Liquid Chromatography (UPLC) analyses in order to determine the metabolic capacity of our psoriatic skin model. Skin substitutes were reconstructed according to the self-assembly method and tested regarding their percutaneous absorption of a topical formulation of tazarotene, followed by UPLC analyses. Histological and immunofluorescence analyses confirmed both the healthy and psoriatic phenotypes. Results from percutaneous absorption showed a significant level of tazarotene metabolite (tazarotenic acid) when th... [more]
Using Real-Time Electricity Prices to Leverage Electrical Energy Storage and Flexible Loads in a Smart Grid Environment Utilizing Machine Learning Techniques
Moataz Sheha, Kody Powell
January 2, 2020 (v1)
Keywords: artificial neural networks, duck curve, dynamic real-time optimization, Energy Storage, Machine Learning, real-time pricing, Renewable and Sustainable Energy, smart grid, smart houses, solar energy
With exposure to real-time market pricing structures, consumers would be incentivized to invest in electrical energy storage systems and smart predictive automation of their home energy systems. Smart home automation through optimizing HVAC (heating, ventilation, and air conditioning) temperature set points, along with distributed energy storage, could be utilized in the process of optimizing the operation of the electric grid. Using electricity prices as decision variables to leverage electrical energy storage and flexible loads can be a valuable tool to optimize the performance of the power grid and reduce electricity costs both on the supply and demand sides. Energy demand prediction is important for proper allocation and utilization of the available resources. Manipulating energy prices to leverage storage and flexible loads through these demand prediction models is a novel idea that needs to be studied. In this paper, different models for proactive prediction of the energy demand... [more]
In Silico Tools and Phosphoproteomic Software Exclusives
Piby Paul, Manikandan Muthu, Yojitha Chilukuri, Steve W. Haga, Sechul Chun, Jae-Wook Oh
January 2, 2020 (v1)
Keywords: bioinformatics, data analysis, databases, phosphoproteomics, proteomics, tools
Proteomics and phosphoproteomics have been emerging as new dimensions of omics. Phosphorylation has a profound impact on the biological functions and applications of proteins. It influences everything from intrinsic activity and extrinsic executions to cellular localization. This post-translational modification has been subjected to detailed study and has been an object of analytical curiosity with the advent of faster instrumentation. The major strength of phosphoproteomic research lies in the fact that it gives an overall picture of the workforce of the cell. Phosphoproteomics gives deeper insights into understanding the mechanism behind development and progression of a disease. This review for the first time consolidates the list of existing bioinformatics tools developed for phosphoproteomics. The gap between development of bioinformatics tools and their implementation in clinical research is highlighted. The challenge facing progress is ideally believed to be the interdisciplinary... [more]
Effect of CuO as Sintering Additive in Scandium Cerium and Gadolinium-Doped Zirconia-Based Solid Oxide Electrolysis Cell for Steam Electrolysis
R. Visvanichkul, S. Peng-Ont, W. Ngampuengpis, N. Sirimungkalakul, P. Puengjinda, T. Jiwanuruk, T. Sornchamni, P. Kim-Lohsoontorn
January 2, 2020 (v1)
Subject: Materials
Keywords: CuO, hydrogen production, sintering additive, solid oxide electrolysis cells, steam electrolysis
The effect of CuO as a sintering additive on the electrolyte of solid oxide electrolysis cells (SOECs) was investigated. 0.5 wt% CuO was added into Sc0.1Ce0.05Gd0.05Zr0.89O2 (SCGZ) electrolyte as a sintering additive. An electrolyte-supported cell (Pt/SCGZ/Pt) was fabricated. Phase formation, relative density, and electrical conductivity were investigated. The cells were sintered at 1373 K to 1673 K for 4 h. The CuO significantly affected the sinterability of SCGZ. The SCGZ with 0.5 wt% CuO achieved 95% relative density at 1573 K while the SCGZ without CuO could not be densified even at 1673 K. Phase transformation and impurity after CuO addition were not detected from XRD patterns. Electrochemical performance was evaluated at the operating temperature from 873 K to 1173 K under steam to hydrogen ratio at 70:30. Adding 0.5 wt% CuO insignificantly affected the electrochemical performance of the cell. Activation energy of conduction (Ea) was 72.34 kJ mol−1 and 74.93 kJ mol−1 for SCGZ and... [more]
Numerical Simulation of the Raceway Zone in Melter Gasifier of COREX Process
Ye Sun, Ren Chen, Zuoliang Zhang, Guoxi Wu, Huishu Zhang, Lingling Li, Yan Liu, Xiaoliang Li, Yan Huang
January 2, 2020 (v1)
Keywords: COREX, gas flow, numerical simulation, raceway zone
The physical and chemical processes in the raceway zone of the COREX melter−gasifier express are similar to those inside the blast furnace. Based on the research achievements on blast furnaces, the unsteady numerical simulation of a gas-solid two-phase in the raceway was carried out by using computational fluid software. The formation process of the raceway in the COREX melter−gasifier was simulated. The shape and size of the raceway were obtained. Then, the effect of gas flow on the depth and height of the raceway was analyzed in this paper.
Numerical Study on Separation Performance of Cyclone Flue Used in Grate Waste Incinerator
Dong-mei Chen, Jing-yu Ran, Jun-tian Niu, Zhong-qing Yang, Ge Pu, Lin Yang
January 2, 2020 (v1)
Keywords: cyclone flue, gas-solid separation, numerical simulation, waste incineration
The traditional treatment of waste incineration flue gas is mostly carried out in low temperatures, but there are some problems such as corrosion of the heating surface at high and low temperatures, re-synthesis of dioxins, and low efficiency. Therefore, it is necessary to remove the pollutants at high temperatures. For the grate waste incinerator, this study proposes an adiabatic cyclone flue arranged at the exit of the first-stage furnace of the grate waste incinerator to pre-remove the fly ash at high temperatures, so as to alleviate the abrasion and corrosion of the tail heating surface. In this paper, computational fluid dynamics (CFD) method is applied to study the performance of a cyclone flue under different structural parameters, and the comprehensive performance of the cyclone flue is evaluated by the technique for order preference by similarity to an ideal solution (TOPSIS) method. The results show that particle separation efficiency increases at first and then decreases wit... [more]
Perfume Encapsulation via Vapor Induced Phase Separation
Mario Ammendola, Raul Rodrigo Gomez, Ricard Garcia Valls
January 2, 2020 (v1)
Subject: Other
Keywords: cellulose acetate, encapsulation, fragrance, sustainable, VIPS
In this study we explored the implementation of the vapor induced phase separation (VIPS) to produce cellulose acetate microcapsules for the encapsulation of a complex mix of fragrances. VIPS is a technique used for membrane preparation, but barely mentioned for microencapsulation. We compared the products from VIPS and a more common microencapsulation process, the immersion precipitation technique (IPS). The capsules prepared via VIPS show a core-shell structure with a thin polymeric shell surrounding the internally empty space, conversely to those produced via IPS, showing an incomplete spherical morphology. This can be attributed to a better control of the precipitation rate of the encapsulation material in the non-solvent thanks to the longer exposition time to the vapor. The activity and encapsulation efficiency of the capsules, obtained through TGA analysis, reached a maximum of ≈75% and ≈90%, respectively. Moreover, a growing trend between the initial active concentration and th... [more]
Effect of Loading on Wheat Germ Drying in a Batch Fluidized Bed for Industrial Production
Der-Sheng Chan, Meng-I Kuo
January 2, 2020 (v1)
Keywords: dehydration, drying rate constant, fluidized bed drying, moisture content, wheat germ
A high loading production in the manufacturing process of wheat germ (WG) drying is important for reducing the production costs. From a cost perspective, the drying performance become more effective in a batch process when the loading increases. The objective of this investigation was to evaluate the drying performance of WG with different loadings, from 2 to 9 kg, at 120 °C in a fluidized bed dryer. The moisture content, according to the American Association of Cereal Chemists (AACC) method, and the water activity using a thermal hygrometer were measured. The absolute humidity, diffusivity of moisture, and thermal efficiency were analyzed using a mathematical model. An analysis of the dehydration flux demonstrated a linear relationship between dehydration time and WG loading using a fluidized bed dryer. The kinetics of WG drying were observed with a simple exponential model used to match the experimental observation, indicating that the drying rate constant decreases with an increase... [more]
Experimental and Numerical Study of Polymer-Retrofitted Masonry Walls under Gas Explosions
Meng Gu, Xiaodong Ling, Hanxiang Wang, Anfeng Yu, Guoxin Chen
January 2, 2020 (v1)
Keywords: field test, gas explosion, masonry wall, polyurea
Unreinforced masonry walls are extensively used in the petrochemical industry and they are one of the most vulnerable components to blast loads. To investigate the failure modes and improve the blast resistances of masonry walls, four full-scale field tests were conducted using unreinforced and spray-on polyurea-reinforced masonry walls subjected to gas explosions. The results suggested that the primary damage of the unreinforced masonry wall was flexural deformation and the wall collapsed at the latter stage of gas explosion. The presence of polyurea coatings could effectively improve the anti-explosion abilities of masonry walls, prevent wall collapses, and retain the flying fragments, which would reduce the casualties and economic losses caused by petrochemical explosion accidents. The bond between the polymer and masonry wall was critical, and premature debonding resulted in a failure of the coating to exert the maximum energy absorption effect. A numerical model for masonry walls... [more]
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