scholarly journals Remote Optical Diagnostics of Nonstationary Aerosol Media in a Wide Range of Particle Sizes

10.5772/35215 ◽  
2012 ◽  
Author(s):  
Olga Kudryashova ◽  
Anatoly Pavlenko ◽  
Boris Vorozhtsov ◽  
Sergey Titov ◽  
Vladimir Arkhipov ◽  
...  
Keyword(s):  
Optical Diagnostics ◽  
Particle Sizes ◽  
Wide Range

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.

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.

scholarly journals Sorting of Particles Using Inertial Focusing and Laminar Vortex Technology: A Review

Micromachines ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 594 ◽  
Author(s):  
Annalisa Volpe ◽  
Caterina Gaudiuso ◽  
Antonio Ancona
Keyword(s):  
Particle Sizes ◽  
Label Free ◽  
Comprehensive Overview ◽  
Efficient Manner ◽  
Medical Treatments ◽  
Inertial Focusing ◽  
Physical Mechanisms ◽  
Micro Fluidics ◽  
Wide Range ◽  
Sample Separation

The capability of isolating and sorting specific types of cells is crucial in life science, particularly for the early diagnosis of lethal diseases and monitoring of medical treatments. Among all the micro-fluidics techniques for cell sorting, inertial focusing combined with the laminar vortex technology is a powerful method to isolate cells from flowing samples in an efficient manner. This label-free method does not require any external force to be applied, and allows high throughput and continuous sample separation, thus offering a high filtration efficiency over a wide range of particle sizes. Although rather recent, this technology and its applications are rapidly growing, thanks to the development of new chip designs, the employment of new materials and microfabrication technologies. In this review, a comprehensive overview is provided on the most relevant works which employ inertial focusing and laminar vortex technology to sort particles. After briefly summarizing the other cells sorting techniques, highlighting their limitations, the physical mechanisms involved in particle trapping and sorting are described. Then, the materials and microfabrication methods used to implement this technology on miniaturized devices are illustrated. The most relevant evolution steps in the chips design are discussed, and their performances critically analyzed to suggest future developments of this technology.

scholarly journals A green chemical route for the synthesis of Mn3O4 nanoparticles

2009 ◽  
Vol 7 (3) ◽  
pp. 555-559 ◽  
Author(s):  
Zehra Durmus ◽  
Hüseyin Kavas ◽  
Abdulhadi Baykal ◽  
Muhammet Toprak
Keyword(s):  
Room Temperature ◽  
Particle Sizes ◽  
Chemical Route ◽  
Tem Analysis ◽  
X Ray ◽  
Profile Fitting ◽  
Transmission Electron ◽  
Wide Range ◽  
Long Range Interactions ◽  
Mn3o4 Nanoparticles

AbstractA novel environmental friendly, room temperature route using an ionic liquid 1-n-butyl-3-methylimidazolium hydroxide ([BMIM]OH) for the synthesis of Mn3O4 nanoparticles is presented. The product was characterized using Fourier transform infrared spectroscopy, X-ray powder diffraction, and transmission electron microscopy. Phase purity was confirmed by XRD, and X-ray line profile fitting determined a crystallite size of 42 ± 11 nm. TEM analysis revealed various morphologies. EPR measurements have indicated the existence of long-range interactions, due to the wide range of particle sizes and morphologies observed.

Rheology of Plastisols of Poly(Vinyl Chloride)

1979 ◽  
Vol 52 (3) ◽  
pp. 676-691 ◽  
Author(s):  
E. A. Collins ◽  
D. J. Hoffmann ◽  
P. L. Soni
Keyword(s):  
Flow Behavior ◽  
Basic Mechanism ◽  
Particle Sizes ◽  
Solvent Interaction ◽  
Factors Affecting ◽  
Shear Rates ◽  
Wide Range ◽  
Size Of Particles ◽  
Increasing Temperature ◽  
Future Work

Abstract The viscosity of PVC plastisols is seen to be affected by numerous variables. Increase in concentration of the resin causes the viscosity to rise, with the increase being more abrupt at the higher concentrations. Deviation from Newtonian behavior also increases with concentration. Decrease in the size of particles results in an increase in viscosity, the effect being more pronounced at low shear rates. Broadening the distribution of particle sizes results in a decrease in viscosity. Porous particles yield plastisols with higher viscosity as compared to nonporous compact particles. The type of plasticizer also affects the viscosity. A plasticizer which is a better solvent for PVC (low value of polymer-solvent interaction parameter, χ) results in a higher viscosity due to an increase in the amount of dissolved polymer. Additives such as alcohols and soaps affect the viscosity in an, as yet, unknown way. Fillers, heat stabilizers, and pigments also increase the viscosity. With increasing temperature, the viscosity first decreases, passes through a minimum and then increases until gelation. With further rise in temperature the viscosity again decreases and then levels out before degradation occurs. In future work, particular emphasis needs to be given to the understanding of the basic mechanism involved in the effect of additives on the flow behavior. Systematic experiments with a range of well-defined particle sizes and over a wide range of shear rates are also needed. A better understanding of the factors affecting the behavior of plastisols will go a long way in changing the art of plastisol formulation to a science.

scholarly journals Resuspension processes in a wide range of particle sizes

2021 ◽  
Vol 249 ◽  
pp. 01003
Author(s):  
Ana María Vidales ◽  
Jesica Benito ◽  
Rodolfo Uñac ◽  
Luc Oger ◽  
Irene Ippolito
Keyword(s):  
Granular Matter ◽  
Time Moment ◽  
Particle Surface ◽  
Critical Conditions ◽  
External Boundary ◽  
Particle Sizes ◽  
Wide Range ◽  
Applied Forces ◽  
The Individual ◽  
Size Scales

Particulate matter offers a broad spectrum of phenomena, well known in the granular matter community. This fact is not only related to the individual or collective behaviour that grains can present depending on the external boundary conditions and/or internal interactions but, to the wide range of particle sizes. This feature confers the possibility of studying a particular phenomenon in different size scales. The main goal of this paper is to describe the detachment of particles from surfaces, where particles go from tens of microns to several millimetres, in a variety of scenarios. All the studied systems presented here have in common the need to determine the critical conditions to lose the equilibrium balance, initiating incipient motion. Solving the right time moment for particle resuspension, consideration of the local interactions between particle, surface and external applied forces can be achieved from different modelling approaches, from deterministic dynamics to statistical mechanics. This paper focuses on some of these approaches performed recently on grains through different size scales.

A universal approach to the preparation of colloidal mesoporous platinum nanoparticles with controlled particle sizes in a wide range from 20 nm to 200 nm

2014 ◽  
Vol 16 (19) ◽  
pp. 8787-8790 ◽  
Author(s):  
Cuiling Li ◽  
Masataka Imura ◽  
Yusuke Yamauchi
Keyword(s):  
Platinum Nanoparticles ◽  
Surfactant Concentration ◽  
Pt Nanoparticles ◽  
Particle Sizes ◽  
Universal Method ◽  
Wide Range ◽  
Universal Approach ◽  
20 Nm ◽  
Mesoporous Platinum

We report a universal method for the preparation of mesoporous Pt nanoparticles with tunable particle sizes by changing the surfactant concentration.

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