scholarly journals Toward the Prediction of Bed Load Rating Curve Parameter Values: The Influence of Scale, Particle Size, and Entrainment Threshold

2018 ◽  
Vol 54 (5) ◽  
pp. 3313-3334 ◽  
Author(s):  
D. Gaeuman ◽  
R. L. Stewart ◽  
S. Pittman
Keyword(s):  
Particle Size ◽  
Bed Load ◽  
Load Rating ◽  
Rating Curve ◽  
Curve Parameter ◽  
Scale Particle ◽  
Parameter Values

Surface Modified Boehmite Aluminas: A Versatile Approach to Nano-scale Particle Dispersion and Nanocomposites

2005 ◽  
Vol 879 ◽  
Author(s):  
Steven L. Baxter
Keyword(s):  
Particle Size ◽  
Physical Property ◽  
Particle Dispersion ◽  
Aqueous Systems ◽  
Nano Scale ◽  
Organic Matrices ◽  
Crystallite Sizes ◽  
Scale Particle ◽  
Physical Property Data ◽  
Surface Modified

AbstractCertain forms of monohydrate aluminum oxide, commonly known as boehmite or pseudoboehmite alumina, are known to disperse in water at low pH to nano-scale dimensions. The upsurge of interest in nano-scale structures has prompted our study of the surface modification of nano-scale boehmite aluminas with organic acids in order to achieve dispersion of these materials in non-aqueous systems and alkaline aqueous systems.This paper discusses the variety of modifiers used to achieve compatibilization and dispersion of nano-sized particles of these boehmite aluminas in aqueous and organic matrices. Organic modification of a variety of crystallite sizes (5-60 nm) and shapes (plates, needles, blocks) has been achieved, including materials of high aspect ratio. We describe the properties of these dispersions, including primary particle size, dispersed particle size, and surface charge. Finally, we present physical property data of polymer nanocomposites prepared from these materials. These materials are based on a commercial process which has been in operation for over 40 years and which has global production capacities of 70,000 tons per annum.

Granulometric Characterization of Flotation Products

2012 ◽  
Vol 727-728 ◽  
pp. 1902-1907
Author(s):  
R.C. Santana ◽  
M.A. Santos ◽  
T.C.M. Santos ◽  
T.A.A. Souza ◽  
Carlos Henrique Ataíde ◽  
...  
Keyword(s):  
Particle Size ◽  
Fine Particle ◽  
Column Height ◽  
Particle Size Fractions ◽  
Granulometric Analysis ◽  
Fine Particle Size ◽  
Distribution Parameters ◽  
Parameter Values ◽  
Feed Samples

This work aimed on the granulometric characterization of flotation products and to analyze the effect of the variables (that were investigated in a flotation work) on the particle size distribution parameters. Besides to compare the parameter values of the granulometric analysis for the concentrate and tailing both results were compared with the parameter values of the flotation feed samples. The analyzed parameters showed lower values for the concentrate products as compared with the parameters for tailing and feed samples. For coarse and fine particle size fractions the column height was the variable that more influenced on the parameter values.

scholarly journals Annual hysteresis in bed load rating curves

1998 ◽  
Vol 34 (9) ◽  
pp. 2393-2399 ◽  
Author(s):  
Douglas B. Moog ◽  
Peter J. Whiting
Keyword(s):  
Bed Load ◽  
Load Rating ◽  
Rating Curves

scholarly journals Laboratory flume experiments with the Swiss plate geophone bed load monitoring system: 1. Impulse counts and particle size identification

2016 ◽  
Vol 52 (10) ◽  
pp. 7744-7759 ◽  
Author(s):  
Carlos R. Wyss ◽  
Dieter Rickenmann ◽  
Bruno Fritschi ◽  
Jens M. Turowski ◽  
Volker Weitbrecht ◽  
...  
Keyword(s):  
Particle Size ◽  
Monitoring System ◽  
Bed Load ◽  
Flume Experiments ◽  
Laboratory Flume ◽  
Load Monitoring ◽  
System 1

scholarly journals Dry magnetic separation technology for the recovery of iron minerals in fine-grained steel slag

2020 ◽  
Vol 40 (1) ◽  
pp. 7-16
Author(s):  
Liang Chang Shi ◽  
Nan Sheng Wang ◽  
Gan Cheng
Keyword(s):  
Particle Size ◽  
Magnetic Separation ◽  
Steel Slag ◽  
Separation Distance ◽  
Magnetic Separator ◽  
Separation Technology ◽  
Fine Grained ◽  
Dry Magnetic Separation ◽  
Concentrate Grade ◽  
Parameter Values

Using the MagNet software package, a permanent magnetic circuit was simulated and a sectorially-spliced magnetic system was designed. Consequently, a new roller permanent magnetic separator with different magnetic field intensities in each roller was developed. The modular structural design allows fine-grained minerals with different magnetic susceptibility to be separated in one pass, according to their different processing characteristic. Steel slag, selected from a factory, was crushed, ground and sieved into different particle size ranges for the single-factor magnetic separation experiments. It was determined that the optimum value ranges for the particle size, magnetic separation distance and rotating frequency were 0.15 mm-0.3 mm, 10 mm-12 mm, 40 Hz～60Hz, respectively; using the chosen parameter values of 0.2mm, 11mm, and 40Hz, the concentrate recovery and concentrate grade of the new separation technology reached up to 52.78% and 64.74%, in comparisson with the existing technology. Thus, it was demonstrated that the self-developed separation technology has the potential to improve the iron recovery of the fine-grained steel slag.

scholarly journals Aircraft Observations of Ice Particle Properties in Stratiform Precipitating Clouds

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Tuanjie Hou ◽  
Hengchi Lei ◽  
Zhaoxia Hu ◽  
Jun Zhou
Keyword(s):  
Particle Size ◽  
Northern China ◽  
Size Spectrum ◽  
Airborne Measurements ◽  
Particle Properties ◽  
Stratiform Clouds ◽  
Convective Cells ◽  
Parameter Values ◽  
Ice Water ◽  
Precipitating Clouds

This study presented airborne measurements of ice particle properties in three stratiform precipitating clouds over northern China. By using horizontal observations at selected altitudes, the distributions of ice water content (IWC), particle habits, and particle size spectrum parameters were investigated. The cloud cases were characterized by high IWC values due to the existence of embedded convective cells. Liquid water contents were rather low with the maxima of less than 0.3 g m−3and the general values of less than 0.1 g m−3. The occurrence of large dendritic crystals as well as rimed capped columns and branched crystals indicated that ice seeding from the above cloud layer (6 km altitude or above) contributed significantly to both high ice crystal number concentrations and IWCs. Horizontal observations at selected levels suggested the general decreasing trend of IWC with decreasing temperature only in part of the cloud layers but not throughout the cold layer of the multilayered stratiform clouds. Both exponential and gamma functions were used to characterize the particle size spectrum parameters. The slope parameter values of exponential distributions were primarily in the range of 103–104 m−1. In comparison, slope values of the gamma distribution fits spanned more and a relationship was found between the dispersion and slope values.

Microwave and electrochemical assisted synthesis of chlorinated iron phthalocyanine nanoparticles

2017 ◽  
Vol 46 (2) ◽  
pp. 156-160 ◽  
Author(s):  
Behnam Seyyedi
Keyword(s):  
Particle Size ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
High Efficiency ◽  
Reduction Reaction ◽  
Metal Catalyst ◽  
Iron Phthalocyanine ◽  
Aromatic Rings ◽  
Content Type ◽  
Scale Particle

Purpose The paper introduces a microwave and electrochemical-assisted method for synthesis of chlorine-derived iron phthalocyanine pigment and oxygen reduction reaction catalyst nanoparticles. The aims of this study are to investigate the possibility of nano-scale particle size (<35 nm), high-efficiency product reaction, remove acidic wastewater, time optimization and maximize number of chlorine on aromatic rings. Design/methodology/approach The paper presents a combined synthesis technique, which does not have the problems of the conventional methods. Chlorinated iron phthalocyanine nanoparticles have been fabricated using phthalic anhydride, urea (high purity), electrochemical-generated iron (II) cations and microwave irradiation as promoter. The approach yields a product of high quality, uniform particle size distribution and high efficiency and that was environment-friendly. Findings The particle size and time needed for the production of chlorinated iron phthalocyanine were about 35 nm and 7 min, respectively. Research limitations/implications The catalyst, that is used in this method, should be weighed carefully. In addition, the solvent should be a saturated solution of NaCl in water. Practical implications The method provides a simple and practical solution to improving the synthesis of an iron-based catalyst for oxygen reduction reaction. Originality/value The combined method for synthesis of chlorinated iron phthalocyanine was novel and can find numerous applications in the industry, especially as an oxygen reduction reaction non-precious metal catalyst.

Study on Milling Periods on the Iron Mill Scale Particle Size and Properties

2012 ◽  
Vol 626 ◽  
pp. 1001-1005 ◽  
Author(s):  
Mohd Zaki Ruhiyuddin ◽  
Che Pa Faizul ◽  
Darus Murizam ◽  
A.R.M. Nazri
Keyword(s):  
Particle Size ◽  
Milling Process ◽  
Optimum Size ◽  
Steel Mill ◽  
Mill Scale ◽  
Rolling Ball ◽  
Scale Properties ◽  
Scale Particle ◽  
Average Size ◽  
The Relationship

The relations between the milling periods with the iron mill scale particle size have been studied. Iron mill scale has been chosen for this research due to the nature of itself, as a by-product. From this research, the average optimum size for the final iron mill scale particle size intended to produce is at 300 μm. Raw iron mill scale received from the industries was in the form of chip with the average size of 10 mm across and 1.5 mm thickness. Three different samples from three different steel mill companies have been used for this study. Rolling ball mill has been used to mill the iron mill scale with two different milling periods, which were two hours and six hours. After the milling process, the iron mill scale was sieved using sieving machine to a few specified grating sizes. Weight of each sample collected from each grating size was calculated in order to get the percentage of the particle size distribution of the iron mill scale after the milling process. Sample collected from Steel Mill 1 (SM1) and Steel Mill 3 (SM3) showing finer particle size produced after the milling period of six hours as compared to two hours. However sample from Steel Mill 2 (SM2) showing different trend of particle size collected as compared to SM1 and SM3. Coarser particle size was collected after the milling periods of six hours as compared to two hours. Characterization process have been conducted to all mill scale samples from each steel mill company in order to determine the relationship between the mill scale properties and the result gathered after the milling process.

scholarly journals Spatial total load rating curve for a large river: a case study of the Tigris River at Baghdad

2019 ◽  
Vol 18 (3) ◽  
pp. 363-376 ◽  
Author(s):  
Ammar A. Ali ◽  
Nadhir A. Al-Ansari ◽  
Qusay Al-Suhail ◽  
Sven Knutsson
Keyword(s):  
Large River ◽  
Load Rating ◽  
Rating Curve ◽  
Total Load ◽  
Tigris River
Sign in / Sign up

Export Citation Format

Share Document