scholarly journals Factors Affecting the Particle Size of Bio-Calcium Carbonate Synthesized from Industrial Eggshell Waste

2018 ◽  
Vol 59 (8) ◽  
pp. 1220-1224 ◽  
Author(s):  
Ajchara I. Putkham ◽  
Somchai Ladhan ◽  
Apipong Putkham
Keyword(s):  
Particle Size ◽  
Calcium Carbonate ◽  
Factors Affecting ◽  
Eggshell Waste

scholarly journals A Numerical Study of the Effect of Particle Size on Particle Deposition on Turbine Vanes and Blades

2021 ◽  
Vol 13 (5) ◽  
pp. 168781402110178
Author(s):  
Zhengang Liu ◽  
Weinan Diao ◽  
Zhenxia Liu ◽  
Fei Zhang
Keyword(s):  
Particle Size ◽  
Particle Deposition ◽  
Numerical Study ◽  
Stokes Number ◽  
Capture Efficiency ◽  
Particle Capture ◽  
Factors Affecting ◽  
Pressure Surface ◽  
Deposition Area ◽  
Turbine Vanes

Particle deposition could decrease the aerodynamic performance and cooling efficiency of turbine vanes and blades. The particle motion in the flow and its temperature are two important factors affecting its deposition. The size of the particle influences both its motion and temperature. In this study, the motion of particles with the sizes from 1 to 20 μm in the first stage of a turbine are firstly numerically simulated with the steady method, then the particle deposition on the vanes and blades are numerically simulated with the unsteady method based on the critical viscosity model. It is discovered that the particle deposition on vanes mainly formed near the leading and trailing edge on the pressure surface, and the deposition area expands slowly to the whole pressure surface with the particle size increasing. For the particle deposition on blades, the deposition area moves from the entire pressure surface toward the tip with the particle size increasing due to the effect of rotation. For vanes, the particle capture efficiency increases with the particle size increasing since Stokes number and temperature of the particle both increase with its size. For blades, the particle capture efficiency increases firstly and then decreases with the particle size increasing.

scholarly journals Physicochemical factors affecting the wettability of copper mine blasting dust

2021 ◽  
Author(s):  
Longzhe Jin ◽  
Jianguo Liu ◽  
Jingzhong Guo ◽  
Jiaying Wang ◽  
Tianyang Wang
Keyword(s):  
Particle Size ◽  
Physicochemical Properties ◽  
Pore Structure ◽  
Total Pore Volume ◽  
Open Pit ◽  
X Rays ◽  
Factors Affecting ◽  
Copper Mine ◽  
Mineral Components ◽  
Hydrophobic Component

AbstractTo investigate the factors affecting the wettability of copper mine blasting dust, the primary blasting dust was collected from an open-pit copper mine and separated into hydrophilic blasting dust (HLBD) and hydrophobic blasting dust (HBBD) using water flotation method. The physicochemical properties of HLBD and HBBD were measured and compared with each other. The properties included particle size distributions (PSDs), micromorphologies, pore structures, mineral components and surface organic carbon functional groups. The results show that particle size and pore structure of the blasting dust are the main factors affecting its wettability. Specifically, particle size of HBBD is smaller than that of HLBD, and their respiratory dust (less than 10 µm) accounts for 61.74 vol% and 53.00 vol%, respectively. The pore structure of HBBD is more developed, and the total pore volume of HBBD is 1.66 times larger than that of HLBD. The identical mineral compositions were detected in HLBD and HBBD by X-rays diffraction (XRD); however, the surface organic hydrophobic component of HBBD is slightly larger than that of HLBD, this may be the reason for the poor wettability of HBBD. This study is significant to understand the effects of physicochemical properties of copper mine blasting dust on its wettability.

Particle Size, Structure and Powdering Process of Calcium Carbonate Nanoparticles Filled Powdered Styrene-Butadiene Rubber

2011 ◽  
Vol 415-417 ◽  
pp. 237-242
Author(s):  
Zhou Da Zhang ◽  
Xue Mei Chen ◽  
Guo Liang Qu
Keyword(s):  
Particle Size ◽  
Calcium Carbonate ◽  
Size Structure ◽  
Average Diameter ◽  
Rubber Matrix ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Particle Structure ◽  
Styrene Butadiene ◽  
New Particles

Calcium carbonate nanoparticles (nano-CaCO3) filled powdered styrene-butadiene rubber (P(SBR/CaCO3) was prepared by adding nano-CaCO3 particles, encapsulant and coagulant to styrene-butadiene rubber (SBR) latex by coacervation, and the particle size distribution, structure were studied. Scanning electron microscopy (SEM) was used to investigate the (P(SBR/CaCO3) particle structure, and a powdering model was proposed to describe the powdering process. The process includes: (i) the latex particles associated with the dispersed nano-CaCO3 particles (adsorption process) to form “new particles” and (ii) the formation of P(SBR/CaCO3) by coagulating “new particles”. The SEM results also shown that the nano-CaCO3 and rubber matrix have formed a macroscopic homogenization in the (P(SBR/CaCO3) particles and nano-CaCO3 dispersed uniformly in the rubber matrix with an average diameter of approximately 50 nm.

scholarly journals Nutrient accumulation and biomass production of alfafa after soil amendment with silicates

Revista CERES ◽  
2014 ◽  
Vol 61 (3) ◽  
pp. 406-413 ◽  
Author(s):  
Angélica Cristina Fernandes Deus ◽  
Leonardo Theodoro Bull ◽  
Juliano Corulli Corrêa ◽  
Roberto Lyra Villas Boas
Keyword(s):  
Particle Size ◽  
Calcium Carbonate ◽  
Soil Amendment ◽  
Soil Acidity ◽  
Steel Slag ◽  
The Other ◽  
Chemical Characteristics ◽  
Nutrient Accumulation ◽  
Particle Size Fractions ◽  
Soil Liming

Studies on the use of silicate correctives in agriculture show that they have great potential to improve soil chemical characteristics, however, little information is available on the reactivity rates of their particle-size fractions. This study investigated whether the reactivity rates obtained experimentally could be considered in the calculation of ECC (effective calcium carbonate) for soil liming, promoting adequate development of alfalfa plants. Six treatments were evaluated in the experiment, consisting of two slag types applied in two rates. The experimental ECC was used to calculate one of the rates and the ECC determined in the laboratory was used to calculate the other. Rates of limestone and wollastonite were based on the ECC determined in laboratory. The rates of each soil acidity corretive were calculated to increase the base saturation to 80%. The treatments were applied to a Rhodic Hapludox and an Alfisol Ferrudalfs. The methods for ECC determination established for lime can be applied to steel slag. The application of slag corrected soil acidity with consequent accumulation of Ca, P, and Si in alfalfa, favoring DM production.

scholarly journals Tailoring Adsorption Induced Switchability of a Pillared Layer MOF by Crystal Size Engineering

2020 ◽  
Author(s):  
Leila Abylgazina ◽  
Irena Senkovska ◽  
Sebastian Ehrling ◽  
Volodymyr Bon ◽  
Petko Petkov ◽  
...  
Keyword(s):  
Particle Size ◽  
Low Frequency ◽  
Polar Molecules ◽  
Adsorption Enthalpy ◽  
Factors Affecting ◽  
University Of Technology ◽  
Order Of Magnitude ◽  
Crystal Structural ◽  
Critical Particle Size ◽  
Characteristic Adsorption

The pillared layer framework DUT-8(Zn) (Zn<sub>2</sub>(2,6-ndc)<sub>2</sub>(dabco), 2,6-ndc = 2,6-naphthalenedicarboxylate, dabco = 1,4-diazabicyclo-[2.2.2]-octane, DUT = Dresden University of Technology) is a prototypical switchable MOF, showing characteristic adsorption and desorption induced open phase (<i>op</i>) to closed phase (<i>cp</i>) transformation associated with huge changes in cell volume. We demonstrate switchability strongly depends on a framework-specific critical particle size (d<i><sub>crit</sub></i>). The solvent removal process (pore desolvation stress contracting the framework) significantly controls the <i>cp</i>/<i>op</i> ratio after desolvation and, subsequently, the adsorption induced switchability characteristics of the system. After desolvation, the dense <i>cp</i> phase of DUT-8(Zn) shows no adsorption-induced reopening and therefore is non-porous for N<sub>2</sub> at 77 K and CO<sub>2</sub> at 195 K. However, polar molecules with a higher adsorption enthalpy, such as the polar molecules such as chloromethane at 249 K and dichloromethane (DCM) at 298 K can reopen the macro-sized crystals upon adsorption. For macro-sized particles, the outer surface energy is negligible and only the type of metal (Zn, Co, Ni) controls the DCM-induced gate opening pressure. The framework stiffness increases from Zn to Ni as confirmed by DFT calculations, X-ray crystal structural analyses, and low frequency Raman spectroscopy. The partial disintegration of the Zn based node hinges produces an overall increased stabilization of<i> cp </i>vs. <i>op</i> phase shifts the critical particle size at which switchability starts to become suppressed to even lower values (d<i><sub>crit</sub></i> < 200 nm) as compared to the Ni-based system (<i>d<sub>crit</sub></i> ≈ 500 nm). Hence, the three factors affecting switchability (energetics of the empty host, (<i>E<sub>op</sub>-E<sub>cp</sub></i>) (I), particle size (II), and desolvation stress (III)) appear to be of the same order of magnitude and should be considered collectively, not individually.

scholarly journals Paleolimnology of Lake Yamanaka as reflected on particle-size distribution

1970 ◽  
Vol 14 ◽  
pp. 35-42 ◽  
Author(s):  
Danda Pani Adhikari
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Size Distribution ◽  
Central Japan ◽  
Size Frequency Distribution ◽  
Factors Affecting ◽  
Mean Grain Size ◽  
The Mean ◽  
Main Factors ◽  
Lake Size

A 17.63 m long bore-hole core extracted from the deepest part of Lake Yamanaka, one of the Fuji-five Lakes at the northeasternfoot of Mount Fuji, central Japan, composed of sediment with intercalations of scoria fallout deposits. The sediment of the upper11.4 m was investigated for grain-size distribution by using a laser diffraction particle size analyser. The mean grain-size profileshowed various degrees of fluctuations, both short-and long-terms, and the size-frequency distribution revealed unimodal-trimodalmixing of sediments. Changes in lake size and water depth appear to be the main factors affecting the variability in the grain-sizedistribution and properties. The lake level appears low during 7000–5000 cal BP and 2800–1150 cal BP and relatively high during5000–2800 cal BP and 1150 cal BP– present.DOI: http://dx.doi.org/10.3126/bdg.v14i0.5437Bulletin of the Department of Geology Vol.14 2011, pp.35-42 

scholarly journals Study on Change Rules of Factors Affecting Gas Loss during Coalbed Air Reverse Circulation Sampling

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Demin Chen ◽  
Wei Long ◽  
Yanyan Li ◽  
Rui Zhang
Keyword(s):  
Particle Size ◽  
Sharp Decrease ◽  
Experimental System ◽  
Gas Content ◽  
Impact Factors ◽  
Extreme Pressure ◽  
Factors Affecting ◽  
Reverse Circulation ◽  
Gas Loss ◽  
Skew Distribution

The gas loss in sampling is the root of coalbed gas content measurement error. The pressure and particle size have a significant impact on the gas loss. Using the self-developed coal particle pneumatic pipeline transportation experimental system, this study investigated the pressure and particle size changes in the sampling pipeline. It is found that the sampling process can be divided into four stages: no flow field stage, sample outburst stage, stable conveying stage, and tail purging stage. The extreme pressure in the sampling pipeline appears at the sample outburst stage; and the pressure in the pipeline has levelled off after sharp decrease in the stable conveying stage. It is also found that the extreme pressure increases first and then decreases with the increase of particle size. The duration of outburst stage is negatively correlated with particle size, and that of stable conveying stage is positively correlated with particle size. In addition, the results show that the loss rate of 1–3 mm particles is the smallest after the test but that particles less than 1 mm increase by about two times and particles greater than 3 mm decrease by more than three times. The study also shows that the particle size distribution of coal samples is a single peak with left skew distribution, and the gas reverse circulation sampling test does not change the location of the peak but makes it higher and sharper. The single size coal sample is more likely to collide than the mixture. This study can help to advance the understanding of impact factors on gas loss during reverse circulation sampling.

Effects of Rotation Speeds and Media Density on Ground Calcium Carbonate during Ultrafine Grinding Process in Planetary Mill

2014 ◽  
Vol 997 ◽  
pp. 542-545
Author(s):  
Yan Ru Chen ◽  
Yi Chen Lu ◽  
Xiao Min Lian ◽  
Chao Yang Li ◽  
Shui Lin Zheng
Keyword(s):  
Particle Size ◽  
Calcium Carbonate ◽  
Rotational Speed ◽  
Planetary Mill ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dry Grinding ◽  
Ultrafine Grinding ◽  
Effects Of Rotation ◽  
Ground Calcium Carbonate

Superfine ground calcium carbonate (GCC) produced by carbonate minerals is a widely used inorganic powder material. In order to get a finer GCC powder with narrow distribution span, the effect of rotational speed and media density on ground GCC were studied by dry grinding GCC in a planetary ball mill under different rotational speed and various media density. The grinding limit-particle size and distribution of grinding calcium carbonate were measured by centrifugal sedimentation granulometer. The structure of GCC was measured by X-ray diffraction. The result shows that low rotational speed and high-density media is conducive to get a product with smaller particle size and narrow size distribution; crystal plane (012) and (122) are more stable than (018) and (116).

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