scholarly journals Particle Size Parameters of Particulate Matter Suspended in Coastal Waters and Their Use as Indicators of Typhoon Influence

2020 ◽  
Vol 12 (16) ◽  
pp. 2581
Author(s):  
Yanxia Liu ◽  
Haijun Huang ◽  
Liwen Yan ◽  
Xiguang Yang ◽  
Haibo Bi ◽  
...  
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Power Law ◽  
Average Particle Size ◽  
Dynamic Processes ◽  
Average Particle ◽  
Suspended Particulate ◽  
Near Shore

The power law particle size distribution (PSD) slope parameter is commonly used to characterize sediment fluxes, resuspension, aggregates, and settling rates in coastal and estuarine waters. However, particle size distribution metrics are also very useful for understanding sediment source and dynamic processes. In this study, a method was proposed to employ the particle size parameters commonly used in sedimentary geology (average particle size (ø), sorting, skewness, and kurtosis) as indicators of changes in sediment dynamic processes, and MODIS images were used to estimate these parameters. The particle size parameters were estimated using a Mie scattering model, Quasi-Analytical Algorithm (QAA) analysis algorithm, and least squares QR decomposition (LSQR) solution method based on the relationship between the power law distribution of the suspended particles and their optical scattering properties. The estimates were verified by field measurements in the Yellow Sea and Bohai Sea regions of China. This method provided good estimates of the average particle size (ø), sorting, and kurtosis. A greater number of wavebands (39) was associated with more accurate particle size distribution curves. Furthermore, the method was used to monitor changes in suspended particulate matter in the vicinity of the Heini Bay of China before and after the passage of a strong storm in August 2011. The particle size parameters represented the influence of a strong typhoon on the distribution of the near-shore sediment and, together with the PSD slope, comprehensively reflected the changes in the near-shore suspended particulate matter. This method not only established the relationship between remote sensing monitoring and the historical sediment record, it also extends the power law model to the application of sediment source and dynamic processes in coastal waters.

scholarly journals Particle Size Distribution of E-Cigarette Aerosols and the Relationship to Cambridge Filter Pad Collection Efficiency

2015 ◽  
Vol 26 (4) ◽  
Author(s):  
Steven L. Alderman ◽  
Chen Song ◽  
Serban C. Moldoveanu ◽  
Stephen K. Cole
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Propylene Glycol ◽  
Collection Efficiency ◽  
Transmission Measurement ◽  
Average Particle ◽  
Electrical Mobility ◽  
Total Particulate Matter

AbstractThe relatively volatile nature of the particulate matter fraction of e-cigarette aerosols presents an experimental challenge with regard to particle size distribution measure-ments. This is particularly true for instruments requiring a high degree of aerosol dilution. This was illustrated in a previous study, where average particle diameters in the 10-50 nm range were determined by a high-dilution, electrical mobility method. Total particulate matter (TPM) masses calculated based on those diameters were orders of magnitude smaller than gravimetrically determined TPM. This discrepancy was believed to result from almost complete particle evaporation at the dilution levels of the electrical mobility analysis. The same study described a spectral transmission measurement of e-cigarette particle size in an undiluted state, and reported particles from 210-380 nm count median diameter. Observed particle number concentrations were in the 10Described here is a study in which e-cigarette aerosols were collected on Cambridge filters with adsorbent traps placed downstream in an effort to capture any material passing through the filter. Amounts of glycerin, propylene glycol, nicotine, and water were quantified on the filter and downstream trap. Glycerin, propylene glycol, and nicotine were effciently captured (> 98%) by the upstream Cambridge filter, and a correlation was observed between filtration efficiency and the partial vapor pressure of each component. The present analysis was largely inconclusive with regard to filter efficiency and particle-vapor partitioning of water. [Beitr. Tabakforsch. Int. 26 (2014) 183-190]

Particle Size Distribution of ZrO2:Pr3+ – Influences of pH, High Power Ultrasound, Surfactant and Dopant Quantity

2007 ◽  
Vol 128 ◽  
pp. 97-100 ◽  
Author(s):  
Stephanie Möller ◽  
Janusz D. Fidelus ◽  
Witold Łojkowski
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
High Power ◽  
Average Particle Size ◽  
Sodium Dodecyl ◽  
Average Particle ◽  
Power Ultrasound ◽  
High Power Ultrasound ◽  
Influence Of Ph

The aim of the work was to examine the influence of pH, high power ultrasound, surfactant and dopant quantity on the particle size distribution of ZrO2:Pr3+, with praseodymium content varying between 0.05 and 10 %. The nanopowders were obtained via a hydrothermal microwave driven process. To establish if the dopant was located on the surface of the zirconia nanoparticles, the particle size distribution, as a function of pH, was measured to obtain an estimate of the isoelectric point of the samples. All results indicated that the dopant was concentrated on the surface: the measurements of the particle size distribution show that the pH corresponding to maximum average particle size changes towards higher values when the Pr content increases. Measurements of the particle size distribution dependency on the application of high power ultrasound and the addition of the sodium dodecyl sulphate surfactant show that, under certain conditions, there is a better stabilisation of the nanopowders in a dispersion and undesirable agglomeration is hindered.

The Influence of Milling Regimes in Beater Mill on Particle Size Distribution and Structural Characteristics of Strontium Hexaferrite Powder

2018 ◽  
Vol 284 ◽  
pp. 158-162
Author(s):  
I.N. Yegorov ◽  
Nikolay Ya. Egorov
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Fluidized Bed ◽  
Structural Parameters ◽  
Average Particle Size ◽  
Strontium Hexaferrite ◽  
Average Particle ◽  
Electromagnetic Effect ◽  
Coarse Material

The paper experimentally substantiates effectiveness of method of milling particulate ferromagnetic materials in magneto fluidized bed. Comparative results of particle size distributions and structural parameters of strontium hexaferrite SrFe12O19 powder obtained by milling coarse material in beater mill without electromagnetic effect and in same mill with formation of magneto fluidized bed from mill material are presented. The magneto fluidized bed is formed by constant and alternating gradient magnetic fields with induction lines that are mutually perpendicular and parallel to the plane of rotating beaters. It is shown that application of electromagnetic effect to milling coarse material in beater mill allowed to greatly intensify that process, significantly increase powder quality: increase particle size distribution uniformity and decrease average particle size from 1558.50 μm to 0.56 μm after 120 minutes of processing in the mill. X-ray diffraction analysis showed that milling in beater mill in magneto fluidized bed leads to reduction of coherent-scattering region size, increase of lattice microstrain and dislocation density, making powder more active during sintering process.

Obtaining and Research of Additive Products from Electro-Erosive Cobalt-Chrome Powders

2020 ◽  
Vol 989 ◽  
pp. 801-805
Author(s):  
Evgeniy V. Ageev ◽  
O.G. Loktionova ◽  
A.Y. Altukhov
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Average Particle Size ◽  
Experimental Studies ◽  
Average Particle ◽  
Cobalt Chromium ◽  
Technical Literature ◽  
Specific Particle ◽  
Cobalt Chrome

The main requirement for powders for additive machines is the spherical shape of the particles. Such particles most compactly fit into a certain volume and provide the “fluidity” of the powder composition in the material supply systems with minimal resistance. Based on the peculiarities of the methods of obtaining spherical powders in order to obtain spherical granules of a regulated grain size, the technology of electroerosive dispersion, which is distinguished by relatively low energy costs and ecological cleanliness of the process, is proposed. The main advantage of the proposed technology is the use of waste as raw materials, which is much cheaper than the pure components used in traditional technologies. In addition, this technology is powder, which allows to obtain powder-alloys. The widespread use of the method of EED for the processing of metal waste into powders for the purpose of their reuse and application in additive technologies is hampered by the lack of complete information in the scientific and technical literature on the influence of the original composition, modes and media on the properties of powders and technologies of practical application. Therefore, the development of technologies for the reuse of EED powders and the evaluation of the effectiveness of their use requires the conduct of comprehensive theoretical and experimental studies. The purpose of this work was to obtain and study additive products from electroerosive cobalt-chromium powders of a specific particle size distribution and to study their microstructure. The granulometry of the obtained powders was determined on a laser analyzer of particle sizes “Analysette 22 NanoTec”. The microstructure of additive samples from cobalt-chromium powders (by transverse polishing) was investigated by optical microscopy on an inverted optical microscope OLYMPUS GX51. On the basis of completed studies, aimed at obtaining and studying additive products from electroerosive cobalt-chrome powders of a specific particle size distribution, and studying their microstructure, it was found that additive samples, obtained from a cobalt-chrome powder with an average particle size of 35,68 microns, have practically no pores.

Nearfield development of the negatively buoyant Rhône River inflow into Lake Geneva as an interflow: suspended particulate matter and associated fluxes.

2021 ◽  
Author(s):  
Violaine Piton ◽  
Frédéric Soulignac ◽  
Ulrich Lemmin ◽  
Graf Benjamin ◽  
Htet Kyi Wynn ◽  
...  
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Suspended Particulate Matter ◽  
Fine Particles ◽  
River Plume ◽  
Lake Geneva ◽  
Suspended Particulate ◽  
Negatively Buoyant

<p>River inflows have a major influence on lake water quality through their input of sediments, nutrients and contaminants. It is therefore essential to determine their pathways, their mixing with ambient waters and the amount and type of Suspended Particulate Matter (SPM) they carry. Two field campaigns during the stratified period took place in Lake Geneva, Switzerland, in the vicinity of the Rhône River plume, at high and intermediate river discharge. Currents, water and sediment fluxes, temperature, turbidity and particle size distribution were measured along three circular transects located at 400, 800 and 1500 m in front of the river mouth. During the surveys, the lake was thermally stratified, the negatively buoyant Rhône River plume plunged and intruded into the metalimnion as an interflow and flowed out in the streamwise direction. Along the pathway, interflow core velocities, SPM concentrations and volumes of particles progressively decreased with the distance from the mouth (by 2-3 times), while interflow cross sections and plume volume increased by 2-3 times due to entrainment of ambient water. The characteristics of the river outflow determined the characteristics of the interflows: i.e. interflow fluxes and concentrations were the highest at high discharge. Both sediment settling and interflow dilution contributed to the observed decrease of sediment discharge with distance from the mouth. The particle size distribution of the interflow was dominated by fine particles (<32 μm), which were transported up to 1500 m away from the mouth and most likely beyond, while large particles (>62 μm) have almost completely settled out before reaching 1500 m. </p>

scholarly journals Preparation and Characterization of NiO Nanoparticles by Anodic Arc Plasma Method

2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
Hongxia Qiao ◽  
Zhiqiang Wei ◽  
Hua Yang ◽  
Lin Zhu ◽  
Xiaoyan Yan
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Specific Surface ◽  
Size Distribution ◽  
Surface Area ◽  
Specific Surface Area ◽  
Average Particle Size ◽  
Average Particle ◽  
Arc Plasma ◽  
Nio Nanoparticles

NiO nanoparticles with average particle size of 25 nm were successfully prepared by anodic arc plasma method. The composition, morphology, crystal microstructure, specific surface area, infrared spectra, and particle size distribution of product were analyzed by using X-ray diffraction (XRD), transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED), Fourier transform infrared (FTIR) spectrum, and Brunauer-Emmett-Teller (BET)N2adsorption. The experiment results show that the NiO nanoparticles are bcc structure with spherical shape and well dispersed, the particle size distribution ranging from 15 to 45 nm with the average particle size is about 25 nm, and the specific surface area is 33 m2/g. The infrared absorption band of NiO nanoparticles shows blue shifts compared with that of bulk NiO.

Preparation of Monodispersed and Nano-Sized Spherical SiO2 Particles by Emulsion Method

2004 ◽  
Vol 449-452 ◽  
pp. 1161-1164 ◽  
Author(s):  
Jong Hwa Baek ◽  
Young Soo Kang ◽  
Seog Young Yoon ◽  
Hong Chae Park
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Mixing Time ◽  
Average Particle Size ◽  
Average Particle ◽  
Amorphous Sio2 ◽  
Emulsion Method ◽  
Sio2 Particles ◽  
20 Nm

Spherical nano-sized SiO2 particles have been synthesized from sodium silicate by emulsion method. The influence of emulsifier content and mixing time on the morphology and particle size distribution of the resulting materials was investigated. The characteristics of the obtained SiO2 particles were examined by means of XRD, SEM, TEM, and PSA. The monodispersed shperical SiO2 with the average particle size 20 nm was obtained at a emulsifer content of 3vol% and mixing time of 60 min using ultrasonic disruptor. After calcining at 1200oC for 2 hrs, the amorphous SiO2 transformed wholly to the crystalline cristobalite. As increase in emulsifier content from 1 to 3 vol% did not nearly influence on the morphology of SiO2 particle but slightly changed the particle size distribution. The average particle size of SiO2 decreased significantly from 100 nm to 20 nm with increasing the mixing time.

Effects of Addition Amount, Particle Size Distribution and Average Particle Size of NaCl Porogen on the Pore Connectivity of Silk Fibroin (SF) /Hydroxyapatite (HA) Porous Composites

2011 ◽  
Vol 332-334 ◽  
pp. 1904-1909
Author(s):  
Zhen Ran Xia ◽  
Miao Liang Luo ◽  
Qin Zhang ◽  
Jing Qu ◽  
Ming Zhong Li
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Silk Fibroin ◽  
Average Particle Size ◽  
Bone Tissue Regeneration ◽  
Average Particle ◽  
Pore Connectivity ◽  
Porous Composites ◽  
Addition Amount

In order to investigate the effects of addition amount, particle size distribution and aver- age particle size of NaCl porogen on the pore connectivity of silk fibroin (SF) / hydroxyapatite (HA) porous composites. In this paper, the SF/HA composites were fabricated by means of isostatic pressing. The pore structure of SF/HA porous composites was observed by Scanning electron microscopy (SEM), and the air permeability was tested by home-made device. Results indicated that the larger addition amount of NaCl particles, the greater scope of NaCl particles size distribution and increased the average particle size of NaCl particles were able to make the pore connectivity of the material improved significantly. The materials with good pore connectivity, which were conducive to the immigration and adhesion of bone repair cells, information transmission and exchange with the outside tissue, and also benefit for bone tissue regeneration.

Particle Size Distribution of Aluminum Powders Obtained by Electric Explosion of Wires

2016 ◽  
Vol 712 ◽  
pp. 20-25
Author(s):  
Nikolay A. Yavorovsky ◽  
Alexey V. Pustovalov ◽  
Sergey P. Zhuravkov ◽  
Olga S. Lutoshkina
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Average Particle Size ◽  
Electric Explosion ◽  
Average Particle ◽  
Aluminum Powders

The paper describes the research into the effect of the energy supplied to the conductor at the time of explosion on the particle size distribution of aluminum powders obtained. Aluminum powders consist of at least three fractions with the average particle size of 20-100 μm, 1-5 μm, and 50-900 nm. The yield of each fraction and average particle size are determined by the level of energy supplied to the conductor.

Synchrotron X-Ray Scattering for the Structural Characterization of Catalysts

1986 ◽  
Vol 30 ◽  
pp. 389-394
Author(s):  
R. J. De Angelis ◽  
A. G. Dhere ◽  
M. A. Maginnis ◽  
P. J. Reucroft ◽  
G. E. Ice ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Profile Analysis ◽  
Average Particle Size ◽  
Initial Slope ◽  
Average Particle ◽  
Particle Size Range ◽  
Diffraction Profile ◽  
X Ray

Discussions exist in the literature concerning the application of single x-ray diffraction profile analysis to determine the average particle size, particle size distribution and root mean squared strain in catalytic systems. Nandi et al. have shown that the single order analysis can give erroneous strain results and is subject to error in the large particle size range. They further indicated that the initial slope of Stokes corrected Fourier coefficients gives more reliable average p article size than that which is calculated from single order peak shape analysis. There is apparent agreement that the average particle size and the particle size distribution measured by single order profile analysis, in small metal particle systems, are reliable.

Sign in / Sign up

Export Citation Format

Share Document