Wide-range meter for measuring average particle sizes in emulsions and suspensions

1986 ◽  
Vol 29 (6) ◽  
pp. 581-584 ◽  
Author(s):  
A. A. Rokhlenko
Keyword(s):  
Average Particle ◽  
Particle Sizes ◽  
Wide Range ◽  
Emulsions And Suspensions

Effects of Multiple Impacts and Size Distribution of Particles on Erosion Predictions Using CFD

2007 ◽  
Author(s):  
Yongli Zhang ◽  
Brenton S. McLaury ◽  
Siamack A. Shirzai
Keyword(s):  
Experimental Data ◽  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Target Material ◽  
Average Particle ◽  
Multiple Impacts ◽  
Cfd Simulations ◽  
Erosion Damage ◽  
Wide Range

Erosion equations are usually obtained from experiments by impacting solid particles entrained in a gas or liquid on a target material. The erosion equations are utilized in CFD (Computational Fluid Dynamics) models to predict erosion damage caused by solid particle impingements. Many erosion equations are provided in terms of an erosion ratio. By definition, the erosion ratio is the mass loss of target material divided by the mass of impacting particles. The mass of impacting particles is the summation of (particle mass × number of impacts) of each particle. In erosion experiments conducted to determine erosion equations, some particles may impact the target wall many times and some other particles may not impact the target at all. Therefore, the experimental data may not reflect the actual erosion ratio because the mass of the sand that is used to run the experiments is assumed to be the mass of the impacting particles. CFD and particle trajectory simulations are applied in the present work to study effects of multiple impacts on developing erosion ratio equations. The erosion equation as well as the CFD-based erosion modeling procedure is validated against a variety of experimental data. The results show that the effect of multiple impacts is negligible in air cases. In water cases, however, this effect needs to be accounted for especially for small particles. This makes it impractical to develop erosion ratio equations from experimental data obtained for tests with sand in water or dense gases. Many factors affecting erosion damage are accounted for in various erosion equations. In addition to some well-studied parameters such as particle impacting speed and impacting angle, particle size also plays a significant role in the erosion process. An average particle size is usually used in analyzing experimental data or estimating erosion damage cases of practical interest. In petroleum production applications, however, the size of sand particles that are entrained in produced fluids can vary over a fairly broad range. CFD simulations are also performed to study the effect of particle size distribution. In CFD simulations, particle sizes are normally distributed with the mean equaling the average size of interest and the standard deviation varying over a wide range. Based on CFD simulations, an equation is developed and can be applied to account for the effect of the particle size distribution on erosion prediction for gases and liquids.

scholarly journals Commercial Cokes and Graphites as Anode Materials for Lithium - Ion Cells

1997 ◽  
Vol 496 ◽  
Author(s):  
David J. Derwin ◽  
Kim Kinoshita ◽  
Tri D. Tran ◽  
Peter Zaleski
Keyword(s):  
Electron Microscopy ◽  
Ethylene Carbonate ◽  
Average Particle Size ◽  
Chemical Properties ◽  
Lithium Ion ◽  
Reversible Capacity ◽  
Bet Surface Area ◽  
Average Particle ◽  
Electrochemical Characteristics ◽  
Wide Range

AbstractSeveral types of carbonaceous materials from Superior Graphite Co. were investigated for lithium ion intercalation. These commercially available cokes, graphitized cokes and graphites have a wide range of physical and chemical properties. The coke materials were investigated in propylene carbonate based electrolytes and the graphitic materials were studied in ethylene carbonate / dimethyl solutions to prevent exfoliation. The reversible capacities of disordered cokes are below 230 mAh / g and those for many highly ordered synthetic (artificial) and natural graphites approached 372 mAh / g (LiC6). The irreversible capacity losses vary between 15 to as much as 200 % of reversible capacities for various types of carbon. Heat treated cokes with the average particle size of 10 microns showed marked improvements in reversible capacity for lithium intercalation. The electrochemical characteristics are correlated with data obtained from scanning electron microscopy (SEM), high resolution transmission electron microscopy (TAM), X - ray diffraction (XRD) and BET surface area analysis. The electrochemical performance, availability, cost and manufacturability of these commercial carbons will be discussed.

Effects of fines on liquefaction behaviour in well-graded materials

2017 ◽  
Vol 54 (10) ◽  
pp. 1460-1471 ◽  
Author(s):  
Katherine A. Kwa ◽  
David W. Airey
Keyword(s):  
Critical State ◽  
Soil Mechanics ◽  
State Parameter ◽  
Triaxial Tests ◽  
Particle Sizes ◽  
Graded Materials ◽  
Fines Content ◽  
Cyclic Resistance ◽  
Wide Range ◽  
Soil Behaviour

This study uses a critical state soil mechanics perspective to understand the mechanics behind the liquefaction of metallic ores during transport by ship. These metallic ores are transported at relatively low densities and have variable gradings containing a wide range of particle sizes and fines contents. The effect of the fines content on the location of the critical state line (CSL) and the cyclic liquefaction behaviour of well-graded materials was investigated by performing saturated, standard drained and undrained monotonic and compression-only cyclic triaxial tests. Samples were prepared at four different gradings containing particle sizes from 9.5 mm to 2 μm with fines (<75 μm) contents of 18%, 28%, 40%, and 60%. In the e versus log[Formula: see text] plane, where e is void ratio and [Formula: see text] is mean effective stress, the CSLs shifted upwards approximately parallel to one another as the fines content was increased. Transitional soil behaviour was observed in samples containing 28%, 40%, and 60% fines. A sample’s cyclic resistance to liquefaction depended on a combination of its density and state parameter, which were both related to the fines content. Samples with the same densities were more resistant to cyclic failure if they contained higher fines contents. The state parameter provided a useful prediction for general behavioural trends of all fines contents studied.

scholarly journals Synthesis and Optical Performances of a Waterborne Polyurethane-Based Polymeric Dye

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Xianhai Hu ◽  
Xingyuan Zhang ◽  
Jin Liu
Keyword(s):  
Molecular Weight ◽  
Particle Size ◽  
Waterborne Polyurethane ◽  
Average Particle ◽  
Particle Sizes ◽  
Hypsochromic Shift ◽  
Absorption Bands ◽  
Polymeric Dye ◽  
Emulsion Particle ◽  
Increasing Temperature

A waterborne polyurethane-based polymeric dye (WPU-CFBB) was synthesized by anchoring 1, 4-bis(methylamino)anthraquinone (CFBB) to waterborne polyurethane chains. The number molecular weight, glass transition temperature, and average emulsion particle size for the polymeric dye were determined, respectively. This polymeric dye exhibited intriguing optical behaviors. The polymeric dye engendered two new absorption bands centered at about 520 nm and 760 nm if compared with CFBB in UV-vis spectra. The 760 nm peak showed hypsochromic shift with the decrease of average particle sizes. The polymeric dye dramatically demonstrated both hypsochromic and bathochromic effects with increasing temperature. The fluorescence intensity of the polymeric dye was much higher than that of CFBB. It was found that the fluorescence intensities would be enhanced from 20°C to 40°C and then decline from 40°C to 90°C. The fluorescence of the polymeric dye emulsion was very stable and was not sensitive to quenchers.

scholarly journals HOMOGENIZATION OF PARTICLE SIZES IN LaTiO2N OXYNITRIDE PIGMENTS BY BEAD-MILLING TECHNIQUE

2012 ◽  
Vol 06 ◽  
pp. 215-220 ◽  
Author(s):  
KAORU SHINNOU ◽  
HIRONORI FUJITO ◽  
TOMOOKI KAWASAKI ◽  
HIDEHITO ANDO ◽  
MAIKO MITO ◽  
...  
Keyword(s):  
Ball Milling ◽  
Absorption Edge ◽  
Aqueous Suspension ◽  
Wavelength Region ◽  
Average Particle ◽  
Particle Sizes ◽  
Bead Milling ◽  
Primary Particles ◽  
Diffuse Reflectivity

Diffuse reflectivity in the longer wavelength region after the absorption edge was studied on the LaTiO 2 N nitrided. It was discussed in the viewpoint of particle sizes by use of ball milling and bead milling technique. The diffuse reflectivity after absorption edge of the LaTiO 2 N powders got lower in accordance with the reduction of particle sizes. In case of LaTiO 2 N aqueous suspension after the bead-milling treatment in which the primary particles were well dispersed, remarkable enhancement of the diffuse reflectivity was observed with decreasing the average particle sizes.

Molecular Dynamics Study of Anatase TiO2 Nanoparticles in Water and Vacuum Environments

2012 ◽  
Author(s):  
George Okeke ◽  
Robert B. Hammond ◽  
S. Joseph Antony
Keyword(s):  
Molecular Dynamics ◽  
Surface Tension ◽  
Surface Energy ◽  
Tio2 Nanoparticles ◽  
Anatase Tio2 ◽  
Particle Sizes ◽  
Metallic Oxides ◽  
Wide Range ◽  
Enhanced Properties ◽  
Dynamics Simulations

Nanoparticles are nanometer sized metallic oxides which possess enhanced properties that are desirable to a wide range of industries. In this study, we investigate structural and surface properties of anatase TiO2 nanoparticles in vacuum and water environments using molecular dynamics simulations. The particle sizes ranged from 2 to 6 nm and simulations were performed at 300 K. Surface energy of the particles in vacuum was seen to be higher than that of the particles in water by about 100% for the smaller particles (i.e. 2 and 3nm) and about 60% for the larger particles (i.e. 4 to 6 nm). Surface energy of the particles in both environments, is seen to increase to a maximum (optimum value) as the particle size increases after which no further significant increase is observed. In vacuum, studies carried out at temperatures ranging from 300–2500 K showed a high dependence of surface energy on temperature. The estimated surface tension of water is seen to agree quite well with that of experiments.

Effects of Dissolving Agents on Particle Size Reduction of Titanium Dioxide Synthesized by Solution Combustion Technique

2016 ◽  
Vol 690 ◽  
pp. 236-239
Author(s):  
Oratai Jongprateep ◽  
Rachata Puranasamriddhi
Keyword(s):  
Particle Size ◽  
Titanium Dioxide ◽  
Sulfuric Acid ◽  
Nitric Acid ◽  
Average Particle Size ◽  
Average Particle ◽  
Particle Sizes ◽  
Solution Combustion ◽  
Initial Reagent ◽  
Combustion Technique

High photocatalytic activity of nanoparticulate titanium dioxide has attracted worldwide attention. Synthesis techniques of the nanoparticles, however, often require high energy supply or costly initial reagents. Solution combustion technique is an energy-effective technique capable of synthesizing nanosized titanium powders. This research aimed at utilizing a less expensive initial reagent in synthesis of nanoparticulate titanium dioxide by the solution combustion technique. The research also examined effects of dissolving agents on chemical composition and particle sizes of the synthesized powders. A low-cost initial reagent, titanium dioxide with average particle size of 154 nanometers, was dissolved in sulfuric acid or dispersed in nitric acid prior to the combustion. Experimental results revealed that the pure anatase phase titanium dioxide was successfully obtained in powders prepared from both sulfuric acid and nitric acid. The average particle size of the powder prepared from sulfuric acid was 77 nanometers, while that of the powder prepared from nitric acid was 117 nanometers. The difference in particle sizes was attributed to solubility of the initial reagent in the acid. Complete solution of initial reagent in sulfuric acid was the main factor attributed to finer particle size.

scholarly journals Biogenic silver nanoparticles from Trichodesma indicum aqueous leaf extract against Mythimna separata and evaluation of its larvicidal efficacy

2017 ◽  
Vol 57 (2) ◽  
pp. 194-200 ◽  
Author(s):  
Abdul A. Buhroo ◽  
Gousul Nisa ◽  
Syed Asrafuzzaman ◽  
Ram Prasad ◽  
Razia Rasheed ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Leaf Extract ◽  
Average Particle ◽  
Particle Sizes ◽  
Mythimna Separata ◽  
Ag Nps ◽  
Leaf Extracts ◽  
Tem Analysis ◽  
Vis Spectroscopy ◽  
Aqueous Leaf Extract

AbstractThe present exploration is focused on the bio-fabrication of silver nanoparticles (Ag NPs) usingTrichodesma indicumaqueous leaf extract as a reducing agent. The synthesized Ag NPs were productively characterized by UV-vis spectroscopy, XRD, and TEM studies. The photosynthesis of Ag NPs was done at room temperature for 24 h and at 60°C. The green synthesis of spherical-shaped Ag NPs bio-fabricated fromT. indicumwith a face centred cubic structure showed average particle sizes of 20–50 nm, which is inconsistent with the particle size calculated by the XRD Scherer equation and TEM analysis. We further explored the larvicidal efficacy of biosynthesized Ag NPs with leaf extracts ofT. indicumagainstMythimna separata. The results showed that Ag NPs (20–50 nm) ofT. indicumpossess good larvicidal activity againstM. separatawith an LC50of 500 ppm. Thus, we can advocate that Ag NPs of 20–50 nm size extracted fromT. indicummay be considered in the pest management programme ofM. separatain future.

scholarly journals Physicochemical Properties of Hom Nil (Oryza sativa) Rice Flour as Gluten Free Ingredient in Bread

Foods ◽  
2018 ◽  
Vol 7 (10) ◽  
pp. 159 ◽  
Author(s):  
Lalana Thiranusornkij ◽  
Parichart Thamnarathip ◽  
Achara Chandrachai ◽  
Daris Kuakpetoon ◽  
Sirichai Adisakwattana
Keyword(s):  
Oryza Sativa ◽  
Physicochemical Properties ◽  
Amylose Content ◽  
Antioxidant Properties ◽  
Rice Flour ◽  
Total Phenolic ◽  
Average Particle ◽  
Particle Sizes ◽  
Gluten Free ◽  
Antioxidant Power

Hom Nil (Oryza sativa), a Thai black rice, contains polyphenolic compounds which have antioxidant properties. The objective of this study was to investigate physicochemical properties of Hom Nil rice flour (HN) and its application in gluten free bread by using Hom Mali 105 rice flour (HM) as the reference. The results demonstrated that HN flour had significantly higher average particle sizes (150 ± 0.58 μm), whereas the content of amylose (17.6 ± 0.2%) was lower than HM flour (particle sizes = 140 ± 0.58 μm; amylose content = 21.3 ± 0.6%). Furthermore, HN contained higher total phenolic compounds (TPC) (2.68 ± 0.2 mg GAE/g flour), total anthocyanins (293 ± 30 mg cyanidin-3-glucoside/g flour), and the ferric reducing antioxidant power (FRAP) (73.5 ± 1.5 mM FeSO4/g) than HM flour (TPC = 0.15 mg GAE/g flour and FRAP = 2.24 mM FeSO4/g flour). In thermal properties, the onset temperature (To), the peak temperature (Tp) and the conclusion (Tc) temperature of HN flour were similar to the values of HM flour. However, HN flour had lower enthalpy change (ΔH) than HM flour. The results showed that HN flour had lower swelling power and higher solubility than HM flour at the temperature between 55 °C and 95 °C. In pasting properties, HN flour also showed lower peak, trough and breakdown viscosity than HM flour. In addition, the bread samples prepared by HN flour had higher value of hardness and lower value of cohesiveness than the bread prepared from HM flour. Taken together, the findings suggest that HN flour could be used as an alternative gluten-free ingredient for bread product.

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