Gas-particle nozzle flows with reaction and particle size change

1981 ◽  
Author(s):  
S. HUNTER ◽  
S. CHERRY ◽  
J. KLIEGEL
Keyword(s):  
Particle Size ◽  
Size Change ◽  
Nozzle Flows

Physical and bacterial processes affecting suspended particulate matter in a tidal river

1998 ◽  
Vol 38 (6) ◽  
pp. 327-335
Author(s):  
Yasunori Kozuki ◽  
Yoshihiko Hosoi ◽  
Hitoshi Murakami ◽  
Katuhiro Kawamoto
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Suspended Particulate Matter ◽  
River Mouth ◽  
Tidal River ◽  
Natural Soil ◽  
Size Change ◽  
Run Off ◽  
Suspended Particulate ◽  
And Behavior

In order to clarify the origin and behavior of suspended particulate matter (SPM) in a tidal river, variation of SPM in a tidal river was investigated with regard to its size and constituents. SPM was separated into three groups according to size. Change of contents of titanium and organic substances of each group of SPM was examined. SPM which was discharged by run-off was transported with decomposition and sedimentation in a tidal river. Concentration of SPM with a particle size greater than 0.45 μm increased due to resuspension in a tidal river. Origin of SPM with a size of less than 0.45 μm at upstream areas was from natural soil and most of such SPM which had been transported settled near a river mouth. It was determined from examination of the CN ratio and the ratio of the number of attached bacteria to free bacteria that SPM with a size greater than 1.0 μm at upstream areas was decomposing intensively. At the downstream areas, SPM with a size of less than 0.45 μm came from the sea. SPM with particle size greater than 1.0 μm consisted of plankton and substances which were decomposed sufficiently while flowing.

Numerical Analysis of Size Reduction of Municipal Solid Waste Particles on the Traveling Grate of a Waste-to-Energy Combustion Chamber

2006 ◽  
Author(s):  
Masato Nakamura ◽  
Marco J. Castaldi ◽  
Nickolas J. Themelis
Keyword(s):  
Particle Size ◽  
Municipal Solid Waste ◽  
Combustion Chamber ◽  
Solid Waste ◽  
Size Reduction ◽  
Waste To Energy ◽  
Size Change ◽  
Model Combining ◽  
Shrinking Core ◽  
Waste Particles

The size reduction of municipal solid waste (MSW) particles on the reverse acting traveling grate of a waste-to-energy (WTE) combustion chamber was estimated by means of a numerical model combining the particle size distributions (PSD) of MSW and combustion residues and the Shrinking Core Model (SCM). This new integrated model was used to simulate the particle behavior on the grate. During their travel on the moving grate, the sizes of the particles are reduced by combustion, breakage, and compaction. This study shows the calculation of the particle size change using this model and comparison of the numerically derived PSDs of MSW and ash particles with experimental data. There is good agreement between calculated and measured values.

Investigation of the Particle Size Change of a La(Ni, Fe)O3 as a Cathode

2019 ◽  
Vol 35 (1) ◽  
pp. 2313-2319 ◽  
Author(s):  
Yoshiteru Yoshida ◽  
Reiichi Chiba ◽  
T. Komatsu ◽  
Masayuki Yokoo ◽  
Katsuya Hayashi ◽  
...  
Keyword(s):  
Particle Size ◽  
Size Change

scholarly journals Formulation of Bicelles Based on Lecithin-Nonionic Surfactant Mixtures

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3066
Author(s):  
Kenji Aramaki ◽  
Keita Adachi ◽  
Miho Maeda ◽  
Jitendra Mata ◽  
Junko Kamimoto-Kuroki ◽  
...  
Keyword(s):  
Particle Size ◽  
Nonionic Surfactant ◽  
Size Distribution ◽  
Soybean Lecithin ◽  
Low Cost ◽  
Surfactant Mixtures ◽  
Temperature Dependent ◽  
Size Change ◽  
Structure Transition ◽  
Biological Studies

Bicelles have been intensively studied for use as drug delivery carriers and in biological studies, but their preparation with low-cost materials and via a simple process would allow their use for other purposes as well. Herein, bicelles were prepared through a semi-spontaneous method using a mixture of hydrogenated soybean lecithin (SL) and a nonionic surfactant, polyoxyethylene cholesteryl ether (ChEO10), and then we investigated the effect of composition and temperature on the structure of bicelles, which is important to design tailored systems. As the fraction of ChEO10 (XC) was increased, a bimodal particle size distribution with a small particle size of several tens of nanometers and a large particle size of several hundred nanometers was obtained, and only small particles were observed when XC ≥ 0.6, suggesting the formation of significant structure transition (liposomes to bicelles). The small-angle neutron scattering (SANS) spectrum for these particles fitted a core-shell bicelle model, providing further evidence of bicelle formation. A transition from a monomodal to a bimodal size distribution occurred as the temperature was increased, with this transition taking place at lower temperatures when higher SL-ChEO10 concentrations were used. SANS showed that this temperature-dependent size change was reversible, suggesting the SL-ChEO10 bicelles were stable against temperature, hence making them suitable for several applications.

Thermal Conductivity of Metal-Oxide Nanofluids: Particle Size Dependence and Effect of Laser Irradiation

2006 ◽  
Vol 129 (3) ◽  
pp. 298-307 ◽  
Author(s):  
Sang Hyun Kim ◽  
Sun Rock Choi ◽  
Dongsik Kim
Keyword(s):  
Thermal Conductivity ◽  
Particle Size ◽  
Effective Thermal Conductivity ◽  
Laser Irradiation ◽  
Volume Fraction ◽  
Suspended Particle ◽  
Titanium Dioxide Nanoparticles ◽  
Size Change ◽  
Conductivity Enhancement ◽  
Wide Range

The thermal conductivity of water- and ethylene glycol-based nanofluids containing alumina, zinc-oxide, and titanium-dioxide nanoparticles is measured using the transient hot-wire method. Measurements are performed by varying the particle size and volume fraction, providing a set of consistent experimental data over a wide range of colloidal conditions. Emphasis is placed on the effect of the suspended particle size on the effective thermal conductivity. Also, the effect of laser-pulse irradiation, i.e., the particle size change by laser ablation, is examined for ZnO nanofluids. The results show that the thermal-conductivity enhancement ratio relative to the base fluid increases linearly with decreasing the particle size but no existing empirical or theoretical correlation can explain the behavior. It is also demonstrated that high-power laser irradiation can lead to substantial enhancement in the effective thermal conductivity although only a small fraction of the particles are fragmented.

scholarly journals Comparing SOA volatility distributions derived from isothermal SOA particle evaporation data and FIGAERO-CIMS measurements

2019 ◽  
Author(s):  
Olli-Pekka Tikkanen ◽  
Angela Buchholz ◽  
Arttu Ylisirniö ◽  
Siegfried Schobesberger ◽  
Annele Virtanen ◽  
...  
Keyword(s):  
Particle Size ◽  
Organic Compounds ◽  
Thermal Desorption ◽  
Process Modelling ◽  
Reasonable Assumption ◽  
Ionization Mass ◽  
Oxidation Condition ◽  
Size Change ◽  
Dry Conditions ◽  
Modelling Techniques

Abstract. The volatility distribution of the organic compounds present in SOA at different conditions is a key quantity that has to be captured in order to describe SOA dynamics accurately. The development of the filter inlet for gases and aerosols (FIGAERO) and its coupling to chemical ionization mass spectrometer (CIMS) has enabled near simultaneous sampling of gas and particle phases of secondary organic aerosol (SOA) through thermal desorption of the particles. The thermal desorption data has recently been shown to be interpretable as a volatility distribution with the use of positive matrix factorization (PMF) method. Similarly, volatility distribution can be inferred from isothermal particle evaporation experiments, when the particle size change measurements are analyzed with process modelling techniques. In this study we compare the volatility distributions that are retrieved from FIGAERO-CIMS and particle size change measurements during isothermal particle evaporation with process modelling techniques. We compare the volatility distributions at two different relative humidity (RH) and two oxidation condition. At high RH conditions, where particles are in a liquid state, we show that the volatility distributions derived the two ways are comparable within reasonable assumption of uncertainty in the effective saturation mass concentrations that are derived from FIGAERO-CIMS data. At dry conditions we demonstrate the volatility distributions are comparable in one oxidation condition and in the other oxidation condition the volatility distribution derived from the PMF analysis shows considerably more high volatility matter than the volatility distribution inferred from particle size change measurements. We also show that the Vogel-Tammann-Fulcher equation together with a recent glass transition temperature parametrization for organic compounds and PMF derived volatility distribution estimate are consistent with the observed isothermal evaporation under dry conditions within the reported uncertainties. We conclude that the FIGAERO-CIMS measurements analyzed with the PMF method are a promising method for inferring organic compounds' volatility distribution, but care has to be taken when the PMF factors are interpreted. Future process modelling studies about SOA dynamics and properties could benefit from simultaneous FIGAERO-CIMS measurements.

scholarly journals Comparing secondary organic aerosol (SOA) volatility distributions derived from isothermal SOA particle evaporation data and FIGAERO–CIMS measurements

2020 ◽  
Vol 20 (17) ◽  
pp. 10441-10458 ◽  
Author(s):  
Olli-Pekka Tikkanen ◽  
Angela Buchholz ◽  
Arttu Ylisirniö ◽  
Siegfried Schobesberger ◽  
Annele Virtanen ◽  
...  
Keyword(s):  
Particle Size ◽  
Organic Compounds ◽  
Thermal Desorption ◽  
Process Modeling ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Oxidation Condition ◽  
Size Change ◽  
Modeling Techniques ◽  
Dry Conditions

Abstract. The volatility distribution of the organic compounds present in secondary organic aerosol (SOA) at different conditions is a key quantity that has to be captured in order to describe SOA dynamics accurately. The development of the Filter Inlet for Gases and AEROsols (FIGAERO) and its coupling to a chemical ionization mass spectrometer (CIMS; collectively FIGAERO–CIMS) has enabled near-simultaneous sampling of the gas and particle phases of SOA through thermal desorption of the particles. The thermal desorption data have been recently shown to be interpretable as a volatility distribution with the use of the positive matrix factorization (PMF) method. Similarly, volatility distributions can be inferred from isothermal particle evaporation experiments when the particle size change measurements are analyzed with process-modeling techniques. In this study, we compare the volatility distributions that are retrieved from FIGAERO–CIMS and particle size change measurements during isothermal particle evaporation with process-modeling techniques. We compare the volatility distributions at two different relative humidities (RHs) and two oxidation conditions. In high-RH conditions, where particles are in a liquid state, we show that the volatility distributions derived via the two ways are similar within a reasonable assumption of uncertainty in the effective saturation mass concentrations that are derived from FIGAERO–CIMS data. In dry conditions, we demonstrate that the volatility distributions are comparable in one oxidation condition, and in the other oxidation condition, the volatility distribution derived from the PMF analysis shows considerably more high-volatility matter than the volatility distribution inferred from particle size change measurements. We also show that the Vogel–Tammann–Fulcher equation together with a recent glass transition temperature parametrization for organic compounds and PMF-derived volatility distribution estimates are consistent with the observed isothermal evaporation under dry conditions within the reported uncertainties. We conclude that the FIGAERO–CIMS measurements analyzed with the PMF method are a promising method for inferring the volatility distribution of organic compounds, but care has to be taken when the PMF factors are analyzed. Future process-modeling studies about SOA dynamics and properties could benefit from simultaneous FIGAERO–CIMS measurements.

scholarly journals Preparation of red elemental nanoselenium by Arabic gum template method

2021 ◽  
Vol 267 ◽  
pp. 02014
Author(s):  
Qingbing Guo ◽  
Xuegui Lin ◽  
Ming He ◽  
Guojie Wu
Keyword(s):  
Particle Size ◽  
Mass Fraction ◽  
Orthogonal Experiment ◽  
Nanometer Scale ◽  
Process Conditions ◽  
Elemental Selenium ◽  
Optimal Process ◽  
Size Change ◽  
Arabic Gum ◽  
Particle Size Analyzer

Red elemental nanoselenium was prepared by reducing sodium selenite with ascorbic acid using Arabic resin as template in this study. The factors effecting on the particle size change of nanoselenium such as reaction time, reactant concentration, template mass fraction and reaction temperature were studied. The orthogonal experiment L9(34) was designed to determine the optimal process conditions. The elemental nanoselenium was characterized by IR and particle size analyzer. The results showed that the stable red elemental selenium with nanometer scale was prepared.

Investigation on Corrosion Base Characteristics and Deep Dehydration Technology of Micro-Droplets in Oil Pipelines

2019 ◽  
Author(s):  
Kai Guo ◽  
Yuling Lv ◽  
Limin He ◽  
Xiaoming Luo ◽  
Donghai Yang
Keyword(s):  
Particle Size ◽  
Electric Field ◽  
Crude Oil ◽  
Pitting Corrosion ◽  
Dispersed Phase ◽  
Water Droplets ◽  
Size Change ◽  
Long Distance ◽  
Oil Pipelines

Abstract Corrosion is an important cause of steel pipeline failure and oil leakage, especially local pitting corrosion in long distance crude oil pipelines. Deep dehydration is of great significance to pipeline anticorrosion, however, further experimental results show that it is very difficult to achieve deep dehydration by a single electric field. Recent studies have shown that the particle size change of dispersed phase for the emulsion with large droplets after electromagnetic synergistic treatment is more obvious than that of a single electric field. In this study, the effect of micro-droplets on corrosion of oil pipelines are revealed. The role of micro-droplets in the process of microbial corrosion and electrochemical corrosion in a strong or weak acid solution for oil pipelines was summarized. A structural model of on-line tubular electromagnetic synergistic intensification coalescing device was established. The size change of particle of the dispersed phase in emulsions was studied. Crude oil and water were used as experimental materials, and the particle size distribution of dispersed phase in emulsions was tested by the evaluation system. The results showed that mean radius, d10 and d50 of water droplets in emulsion treated by electromagnetic synergism are larger than those treated by a single electric field. Strengthening droplets coalescence by electromagnetic synergism is also effective on emulsions whose particle size of the dispersed phase is less than 100μm. The role of micro-droplets in pitting corrosion is summarized based on corrosion channels. In the process of microbial corrosion and electrochemical corrosion in strong or weak acid solution, the role of water is presented in two aspects like participating in the reaction and providing ion electron transmission media. Analogous to culture medium, micro water droplets can be called corrosion medium for pitting corrosion in long-distance crude oil pipelines. A structural model of on-line tubular electromagnetic synergistic intensification coalescing device was established, including an electric field generation device and a magnetic field excitation component with orthogonal distribution and synchronous synergy. And emulsions are treated by electric and magnetic fields while flowing through the medium channel. The particle size change of dispersed phase in emulsions with average particle size of dispersed phase less than 100μm was experimental studied. It is found that mean radius, d10 and d50 of water droplets in emulsion treated by electromagnetic synergism are larger than that by a single electric field. Therefore, electromagnetic synergism can further enhance the dehydration depth compared with a single electric field.

Sign in / Sign up

Export Citation Format

Share Document