scholarly journals Influence of Starting Material Particle Size on Pellet Surface Roughness

2013 ◽  
Vol 15 (1) ◽  
pp. 131-139 ◽  
Author(s):  
Srimanta Sarkar ◽  
Bee Hwee Ang ◽  
Celine Valeria Liew
Keyword(s):  
Surface Roughness ◽  
Particle Size ◽  
Starting Material ◽  
Material Particle ◽  
Pellet Surface

Influence of Abrasive on Planarization Polishing with the Tiny-Grinding Wheel Cluster Based on the Magnetorheological Effect

2009 ◽  
Vol 76-78 ◽  
pp. 229-234 ◽  
Author(s):  
Qiu Sheng Yan ◽  
Yong Yang ◽  
Jia Bin Lu ◽  
Wei Qiang Gao
Keyword(s):  
Surface Roughness ◽  
Particle Size ◽  
Material Removal Rate ◽  
Material Removal ◽  
Magnetic Particles ◽  
Optical Glass ◽  
Removal Rate ◽  
Grinding Wheel ◽  
Material Particle ◽  
Material Removal Model

Experiments were conducted to polish optical glass with the magnetorheological (MR) effect-based tiny-grinding wheel cluster, and the influences of abrasive material, particle size and content on the material removal rate and surface roughness are investigated. The experimental results indicate that: the higher the hardness of abrasives, the higher the material removal rate, but the abrasives with lower hardness can obtain lower surface roughness. The better polishing quality of the workpiece can be obtained when the particle size of abrasives is similar to the particle size of magnetic particles. Moreover, the content of abrasives has an optimum value, and the material removal rate and the surface quality can not be improved further when the content of abrasives exceeds the optimum value. On the basis of above, the material removal model of the new planarization polishing technique is presented.

scholarly journals Leaching Behaviour of Construction and Demolition Wastes and Recycled Aggregates: Statistical Analysis Applied to the Release of Contaminants

2021 ◽  
Vol 11 (14) ◽  
pp. 6265
Author(s):  
Alessandra Diotti ◽  
Giovanni Plizzari ◽  
Sabrina Sorlini
Keyword(s):  
Particle Size ◽  
Statistical Analysis ◽  
Raw Materials ◽  
Primary Source ◽  
Recycled Aggregates ◽  
Critical Parameters ◽  
Material Particle ◽  
Analysis Methodology ◽  
Construction And Demolition Wastes ◽  
Leaching Behaviour

Construction and demolition wastes represent a primary source of new alternative materials which, if properly recovered, can be used to replace virgin raw materials partially or totally. The distrust of end-users in the use of recycled aggregates is mainly due to the environmental performance of these materials. In particular, the release of pollutants into the surrounding environment appears to be the aspect of greatest concern. This is because these materials are characterized by a strong heterogeneity which can sometimes lead to contaminant releases above the legal limits for recovery. In this context, an analysis of the leaching behaviour of both CDWs and RAs was conducted by applying a statistical analysis methodology. Subsequently, to evaluate the influence of the particle size and the volumetric reduction of the material on the release of contaminants, several experimental leaching tests were carried out according to the UNI EN 12457-2 and UNI EN 12457-4 standards. The results obtained show that chromium, mercury, and COD are the most critical parameters for both CDWs and RAs. Moreover, the material particle size generally affects the release of contaminants (i.e., finer particles showed higher releases), while the crushing process does not always involve higher releases than the sieving process.

Assessment of Lost Circulation Material Particle-Size Distribution on Fracture Sealing: A Numerical Study

2022 ◽  
pp. 1-15
Author(s):  
Lu Lee ◽  
Arash Dahi Taleghani
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Numerical Study ◽  
Fluid Loss ◽  
Material Particle ◽  
Lost Circulation ◽  
Fracture Sealing ◽  
Discrete Element Methods ◽  
Lost Circulation Materials

Summary Lost circulation materials (LCMs) are essential to combat fluid loss while drilling and may put the whole operation at risk if a proper LCM design is not used. The focus of this research is understanding the function of LCMs in sealing fractures to reduce fluid loss. One important consideration in the success of fracture sealing is the particle-size distribution (PSD) of LCMs. Various studies have suggested different guidelines for obtaining the best size distribution of LCMs for effective fracture sealing based on limited laboratory experiments or field observations. Hence, there is a need for sophisticated numerical methods to improve the LCM design by providing some predictive capabilities. In this study, computational fluid dynamics (CFD) and discrete element methods (DEM) numerical simulations are coupled to investigate the influence of PSD of granular LCMs on fracture sealing. Dimensionless variables were introduced to compare cases with different PSDs. We validated the CFD-DEM model in reproducing specific laboratory observations of fracture-sealing experiments within the model boundary parameters. Our simulations suggested that a bimodally distributed blend would be the most effective design in comparison to other PSDs tested here.

scholarly journals Effect of particle size distribution on rheological properties of chocolate

2020 ◽  
Vol 11 (11) ◽  
pp. 9547-9559
Author(s):  
Annika Feichtinger ◽  
Elke Scholten ◽  
Guido Sala
Keyword(s):  
Surface Roughness ◽  
Particle Size ◽  
Particle Size Distribution ◽  
Rheological Properties ◽  
Size Distribution ◽  
Particle Shape ◽  
Size Ratio ◽  
Particle Size Ratio ◽  
Effect Of Particle Size

Particle size distribution and particle size ratio have an important effect on rheological properties of model chocolate samples, but also other factors like particle shape, surface roughness and hydrophilicity should be taken into account.

scholarly journals Effect of Material Particle Size on Reduction rate of Hematite and Quaternary Calcium Ferrite Mixtures

2013 ◽  
Vol 99 (6) ◽  
pp. 401-406 ◽  
Author(s):  
Daisuke Noguchi ◽  
Ryouta Ikezaki ◽  
Ko-Ichiro Ohno ◽  
Takayuki Maeda ◽  
Kouki Nishioka ◽  
...  
Keyword(s):  
Particle Size ◽  
Reduction Rate ◽  
Calcium Ferrite ◽  
Material Particle

Experimental XRF Calculation Method with Correction for a Polydisperse Material Particle Size

1991 ◽  
Vol 35 (B) ◽  
pp. 1055-1061
Author(s):  
V. V. Zagorodny ◽  
V. I. Karmanov
Keyword(s):  
Particle Size ◽  
Sample Preparation ◽  
Particle Size Distribution ◽  
Fluorescence Intensity ◽  
Calculation Method ◽  
Multicomponent Mixtures ◽  
Material Particle ◽  
Polydisperse Material ◽  
Multicomponent Material ◽  
Welding Materials

AbstractA new experimental calculation method for polydisperse (i.e. heterogeneous) multicomponent material analysis has been developed using the dependence of element fluorescence intensity on the particle size and its distribution in the specimen. It is shown that correction of the influence of matrix particle size is possible using this experimental calculation method. For its application, the information on particle size distribution for each of the components is sufficient. Sample preparation includes only the pelleting of specimens under standard conditions. The efficiency of the method proposed is demonstrated by the analysis of the multicomponent mixtures of welding materials.

Fundamental Studies on the Mechanisms of Oxide CMP

2000 ◽  
Vol 613 ◽  
Author(s):  
Uday Mahajan ◽  
Seung-Mahn Lee ◽  
Rajiv K. Singh
Keyword(s):  
Surface Roughness ◽  
Particle Size ◽  
Wear Rate ◽  
Removal Rate ◽  
Polished Surface ◽  
Electrostatic Repulsion ◽  
Polishing Process ◽  
Negative Surface ◽  
Negative Surface Charge ◽  
Slurry Stability

ABSTRACTIn this paper, results of studies on the addition of salt to a polishing slurry, in terms of its effect on slurry stability, SiO2 polishing rate and surface roughness of the polished surface are presented. Three salts, viz. LiCl, NaCl and KCl were selected, and three concentrations were tested. Polishing rate measurements using these slurries show that adding salt leads to increased removal rate without affecting surface roughness significantly. Based on these results, we can say that the agglomerates formed by adding salt to the slurry are fairly soft and easily broken during the polishing process. In addition, turbidity and particle size measurements show that significant coagulation of the particles in the slurry occurs only at the highest salt concentration, and is fastest for LiCl and NaCl, with KCl showing the slowest coagulation. From these results, it can be concluded that the enhancement in polish rate is due to increased contact at the wafer-pad-slurry interface, and not due to formation of larger agglomerated particles in the slurry. This is because of reduced electrostatic repulsion between these three surfaces, due to the screening of their negative surface charge by the metal ions in solution, resulting in a higher wear rate.

Effect of Ni film structure and surface morphology on the growth of graphene by PECVD

2018 ◽  
Vol 11 (01) ◽  
pp. 1850011
Author(s):  
Lipeng Ren ◽  
Wei Wang ◽  
Chenglei Yu ◽  
Saisai Duan ◽  
Wenjing Ma ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Particle Size ◽  
Electron Beam ◽  
Low Temperature ◽  
Surface Morphology ◽  
Silicon Substrate ◽  
Amorphous State ◽  
Electron Beam Evaporation ◽  
Film Structure ◽  
Bilayer Structure

In this work, Ni films with the thickness of 50[Formula: see text]nm were deposited on (110) silicon substrate by electron beam evaporation at the temperature of 125[Formula: see text]C, 300[Formula: see text]C and 500[Formula: see text]C. Graphene was prepared on Ni films by PECVD to study the effect of Ni film structure and surface morphology on the graphene grown by PECVD. The result shows that the particle size and surface roughness of Ni film increase, as the temperature of substrate go up. The Ni film deposited at 125[Formula: see text]C exhibits amorphous state, and the Ni films deposited at 300[Formula: see text]C and 500[Formula: see text]C exhibit (111) microcrystal structure. The graphene grown on the microcrystalline Ni film deposited at 300[Formula: see text]C is the bilayer structure with less defects and uniform morphology. The graphene prepared on the microcrystalline Ni film deposited at 500[Formula: see text]C has more defects, layers and obvious plane undulation. The analysis indicates that microcrystalline Ni film deposited at 300[Formula: see text]C can be used by PECVD at low temperature to prepare a bilayer graphene with less defects and uniform morphology.

scholarly journals Physicochemical Characterization of a Dental Eggshell Powder Abrasive Material

2017 ◽  
Vol 15 (4) ◽  
pp. e341-e346 ◽  
Author(s):  
Stanley C. Onwubu ◽  
Anisa Vahed ◽  
Shalini Singh ◽  
Krishnan M. Kanny
Keyword(s):  
Surface Roughness ◽  
Particle Size ◽  
Ftir Spectroscopy ◽  
Physicochemical Characterization ◽  
Xrd Analysis ◽  
Physicochemical Characteristics ◽  
Threshold Limit Value ◽  
Abrasive Material ◽  
Limit Value ◽  
Transmission Electron

Background This study aimed to determine the physicochemical characteristics of an eggshell-based dental abrasive material. Methods The eggshell powder abrasive material (EPAM) was synthesized by ball milling eggshell powder and surfactants. Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM) and a laser diffraction particle size analyzer (PSA) were used to characterize EPAM. In addition, the abrasive characteristics of EPAM were evaluated by comparison using poly(methyl methacrylate) (PMMA) resins. Surface roughness (Ra) was measured using a profilometer. Results The FTIR spectroscopy and XRD analysis confirmed that the carbonate product was primarily calcite (97.3%) with traces of graphite 2H (1.3%) and thenardite (1.4%). The TEM imagery revealed irregular particles in EPAM. The PSA analysis of the particle size distribution showed EPAM to be a superfine powder (0.3 μm to 50 nm). In addition, the 50-nm EPAM (Ra = 0.04 μm) measured the lowest Ra value when compared with pumice (Ra = 0.08 μm). Conclusions The salient features of this study indicate that EPAM can naturally replace calcite, which is generally mined and used as a dental abrasive material. In addition, and regarding the abrasive characteristics of EPAM in reducing the surface roughness of PMMA resin specimens, this study conclusively showed that EPAM effectively reduces the surface roughness below the threshold limit value of 0.2 μm. Potentially, EPAM could reduce waste disposal problems while enabling an economic benefit from using eggshell waste material.

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