Pulsed Wire Discharge Apparatus for Mass Production of Nanosized Powders

2006 ◽  
Vol 11-12 ◽  
pp. 315-318 ◽  
Author(s):  
Seigo Nishimura ◽  
Y. Hayashi ◽  
Tsuneo Suzuki ◽  
Tadachika Nakayama ◽  
Hisayuki Suematsu ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Mass Production ◽  
Nanosized Powders ◽  
Pulsed Wire Discharge ◽  
Surface Diameter ◽  
Median Diameter ◽  
The Mean

A pulsed wire discharge (PWD) apparatus for mass production of nanosized powders was developed. The apparatus had a wire feeder, and could prepare 1.5 g of Cu powder in 200 sec. The mean surface diameter of Cu powder was 86 nm. The particle size distribution of the powder prepared by 100 discharges was increased than that by one discharge. In addition, the median diameter of the powder after the 100 discharges was larger than that by one discharge. A part of the nanosized powders in production chamber of the apparatus would be grown by the deposition of plasma or vapor formed by the next discharge.

scholarly journals Particle Size Distribution of Copper Nanosized Powders Prepared by Pulsed Wire Discharge

2005 ◽  
Vol 125 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Keiichi Murai ◽  
Chuhyun Cho ◽  
Hisayuki Suematsu ◽  
Weihua Jiang ◽  
Kiyoshi Yatsui
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Nanosized Powders ◽  
Pulsed Wire Discharge

Batch Precipitation of Lead Iodide

1994 ◽  
Vol 59 (6) ◽  
pp. 1301-1304
Author(s):  
Jaroslav Nývlt ◽  
Stanislav Žáček
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Crystal Size ◽  
Lead Nitrate ◽  
Lead Iodide ◽  
Constant Rate ◽  
Mean Size ◽  
The Mean

Lead iodide was precipitated by a procedure in which an aqueous solution of potassium iodide at a concentration of 0.03, 0.10 or 0.20 mol l-1 was stirred while an aqueous solution of lead nitrate at one-half concentration was added at a constant rate. The mean size of the PbI2 crystals was determined by evaluating the particle size distribution, which was measured sedimentometrically. The dependence of the mean crystal size on the duration of the experiment exhibited a minimum for any of the concentrations applied. The reason for this is discussed.

scholarly journals MINERAL ABUNDANCE AND PARTICLE SIZE DISTRIBUTION DERIVED FROM IN-SITU SPECTRA MEASUREMENTS OF YUTU ROVER OF CHANG’E-3

2017 ◽  
Vol XLII-3/W1 ◽  
pp. 85-89
Author(s):  
H. Lin ◽  
X. Zhang ◽  
Y. Yang ◽  
X. Wu ◽  
D. Guo
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Landing Site ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Particle Sizes ◽  
The Mean ◽  
The Difference ◽  
Yutu Rover

From geologic perspective, understanding the types, abundance, and size distributions of minerals allows us to address what geologic processes have been active on the lunar and planetary surface. The imaging spectrometer which was carried by the Yutu Rover of Chinese Chang’E-3 mission collected the reflectance at four different sites at the height of ~ 1 m, providing a new insight to understand the lunar surface. The mineral composition and Particle Size Distribution (PSD) of these four sites were derived in this study using a Radiative Transfer Model (RTM) and Sparse Unmixing (SU) algorithm. The endmembers used were clinopyroxene, orthopyroxene, olivine, plagioclase and agglutinate collected from the lunar sample spectral dataset in RELAB. The results show that the agglutinate, clinopyroxene and olivine are the dominant minerals around the landing site. In location Node E, the abundance of agglutinate can reach up to 70 %, and the abundances of clinopyroxene and olivine are around 10 %. The mean particle sizes and the deviations of these endmembers were retrieved. PSDs of all these endmembers are close to normal distribution, and differences exist in the mean particle sizes, indicating the difference of space weathering rate of these endmembers.

Analysis of the Mean Diameters and Particle-Size Distribution in Powders

2010 ◽  
Vol 27 (5-6) ◽  
pp. 158-164 ◽  
Author(s):  
Pedro González-Tello ◽  
Fernando Camacho ◽  
José. M. Vicaria ◽  
Pedro A. González
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
The Mean

Laboratory evaluation of airborne particulate control treatments for simulated aircraft crash recovery operations involving carbon fiber composite materials

2015 ◽  
Vol 13 (5) ◽  
pp. 468 ◽  
Author(s):  
Matthew Ferreri, MS, CIH ◽  
Jeremy Slagley, PhD, CIH, CSP ◽  
Daniel Felker, PhD
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Composite Fiber ◽  
Airborne Particulate ◽  
Treatment Protocols ◽  
Median Diameter ◽  
Particulate Control ◽  
Crash Recovery ◽  
Aircraft Crash

Objective: This study compared four treatment protocols to reduce airborne composite fiber particulates during simulated aircraft crash recovery operations. Design: Four different treatments were applied to determine effectiveness in reducing airborne composite fiber particulates as compared to a “no treatment” protocol. Both “gold standard” gravimetric methods and real-time instruments were used to describe mass per volume concentration, particle size distribution, and surface area. The treatment protocols were applying water, wetted water, wax, or aqueous film-forming foam (AFFF) to both burnt and intact tickets of aircraft composite skin panels. The tickets were then cut using a small high-speed rotary tool to simulate crash recovery operations.Setting: Aerosol test chamber.Subjects, participants: None.Interventions: Airborne particulate control treatments.Main outcome measures: Measures included concentration units of milligrams per cubic meter of air, particle size distribution as described by both count median diameter and mass median diameter and geometric standard deviation of particles in micrometers, and surface area concentration in units of square micrometers per cubic centimeter. Finally, a Monte Carlo simulation was run on the particle size distribution results. Comparison was made via one-way analysis of variance.Results: A significant difference (p < 0.0001) in idealized particle size distribution was found between the water and wetted water treatments as compared to the other treatments for burnt tickets.Conclusions: Emergency crash recovery operations should include a treatment of the debris with water or wetted water. The resulting increase in particle size will make respiratory protection more effective in protecting the response crews.

scholarly journals Effect of particle size distribution on strength of precipitation-hardened alloys

2004 ◽  
Vol 19 (9) ◽  
pp. 2765-2773 ◽  
Author(s):  
A.J. Kulkarni ◽  
K. Krishnamurthy ◽  
S.P. Deshmukh ◽  
R.S. Mishra
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Particle Distribution ◽  
General Trend ◽  
Dislocation Motion ◽  
Effect Of Particle Size ◽  
The Mean ◽  
Simulation Results ◽  
Critical Resolved Shear Stress

Aging of precipitation hardened alloys results in particle coarsening, which in turn affects the strength. In this study, the effect of particle size distribution on the strength of precipitation-hardened alloys was considered. To better represent real alloys, the particle radii were distributed using the Wagner and Lifshitz and Slyozov (WLS) particle size distribution theory. The dislocation motion was simulated for a range of mean radii and the critical resolved shear stress (CRSS) was calculated in each case. Results were also obtained by simulating the dislocation motion through the same system but with the glide plane populated by equal strength particles, which represent mean radii for each of the aging times. The CRSS value with the WLS particle distribution tends to decrease for lower radii than it does for the mean radius approach. The general trend of the simulation results compares well with the analytical values obtained using the equation for particle shearing and the Orowan equation.

scholarly journals Comparison of hazes in freshly bottled and aged beers by multiple angle turbidimetry

2010 ◽  
Vol 28 (No. 1) ◽  
pp. 36-43
Author(s):  
P. Sladký ◽  
R. Koukol
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Scattered Light ◽  
Distribution Measurement ◽  
Particle Size Distribution Measurement ◽  
Mean Size ◽  
The Mean ◽  
Dual Angle

The hazes of freshly bottled and aged pale lager beers determined with the 12° and 90° dual angle laboratory hazemeters and 10° to 90° range photogoniometer were compared and evaluated. The instruments were standardised in EBC formazin units. In freshly bottled beer, the forward (12°–25°) haze values were smaller approximately by a factor of three than the nephelometric (90°) values which yielded 0.33 EBC units. In aged beer, the forward haze was greater than the nephelometric one. Whereas the aged beer showed the greatest and the fresh beer the lowest intensity of scattered light, the formazin suspension intensity was in between. Due to the standardisation of the beer scattered intensities by relation to that of formazin, the standardised nephelometric haze in non-aged beer was greater than the forward haze, and vice versa in aged beer. The greater forward than the nephelometric haze in aged beer was caused by the growth of haze particles above the mean size of formazin particles which was larger than 2 &mu;m as confirmed by the particle size distribution measurement.

scholarly journals Conductivity prediction of proppant-packs based on particle size distribution under variable stress conditions

2020 ◽  
Vol 205 ◽  
pp. 03010
Author(s):  
Tiancheng Liang ◽  
Jinwei Zhang ◽  
Chuanyou Meng ◽  
Nailing Xiu ◽  
Bo Cai ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Hydraulic Fracturing ◽  
Size Distribution ◽  
Particle Diameter ◽  
Particle Packing ◽  
Stress Conditions ◽  
Sieve Analysis ◽  
Proper Size ◽  
Median Diameter

The conductivity of the proppant-packs is critical in the productivity of hydraulically fractured wells. Proppants are also the best medium for studying particle packing. Sand and ceramic media are two most common proppants used for hydraulic fracturing. This study focuses on investigate the relation between conductivity and properties of proppant-packs, the particle-size distribution, porosity and mean particle diameter have been measured. The porosity of the proppant pack under zero pressure is determined from bulk density and apparent density. To accurately measure the porosity under variable closed stress conditions, the compressed width was taken into consideration. The particle size distribution was measured from sieve analysis. The paper presents results obtained by conducting routine conductivity test on a variety of proppants. The conductivity-porosity relationships are nonlinear. The conductivity is most sensitive to mean grain size, followed by closed stress, and then sorting. Larger median diameter always correlates to higher conductivity at low stress. Loss of conductivity with stress is more severe for large particles sands than small particles. The binomial method can be used to calculate the conductivity of different types and mesh proppants, which is shown to fit conductivity-mean diameter data successfully. The research is of guiding significance to choose the proper size distribution proppants in hydraulic fracturing. Meanwhile, the binomial method is a better predictor of proppant-packs conductivity based on particle size distribution.

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