Hydrodynamics of gas–solid fluidization in tapered beds

Comparative pulmonary toxicity study of nano-TiO 2 particles of different sizes and agglomerations in rats: Different short- and long-term post-instillation results

The dynamics of fine particles of different sizes in the vicinity of DC conductors have been studied. It was observed that the particles aggregated with each other and were distributed in parallel chains on the surface of the conductors. Moreover, an interesting “layering phenomenon” was discovered in the spaces where particles concentrated. Variations in the concentration of particles of different sizes were measured in the sump. A higher voltage and a larger particle size were found to be associated with a faster decrease in the particle concentration. Based on a coupled model of the electric field and the force field, the different forces acting on particles of different sizes were analyzed. Particles of different sizes were observed to reunite into a spindle shape in the calculation space, with large particles playing a leading role. According to the calculation results, the particles around the conductor will settle and reunite, and the gathering of particles accelerates the settlement.

The effect of particle size on the physicochemical and noodle quality of wheat flours was investigated. Granular wheat flour was ground by adjusting the distance between the rolls (0.02, 0.04, 0.06, 0.08, and 0.1mm) of the flour mill to obtain wheat flour in five different particle sizes. The results showed that milling intensity significantly reduced the particle size and increased the damaged starch content and sedimentation value, but there were no significant differences in protein or ash contents. The reduction of wheat flour particle size significantly decreased the peak viscosity, trough viscosity, final viscosity, breakdown, and setback of the blends, while there were no significant differences in pasting temperature. Stress relaxation characteristics indicated that as the particle size of wheat flour decreased, dough hardness increased. The noodles made from wheat flour with a smaller particle size had a higher water absorption rate and cooking loss rate. Textural profile analysis parameters showed that as the particle size of wheat flour decreased, the hardness, chewiness, recovery, and adhesiveness of noodles showed increasing trends, and there was no significant difference in elasticity. In summary, it is found that the quality of the noodles made by sample C (D50 : 78.47µm) is better.

This work aims to investigate the effect of recycled material and effect of particle size on the mechanical properties of the recycled material. Tested material is polyamide 6. Every manufacture of any plastic parts produces certain amount of waste, such as defective injects or cold runner system from injection molding technology. When size of this material is reduced, particles of different sizes are made. From large particles similar to the original granulate material, to dust particles. This size variation can cause problems during subsequent processing. These particles of different size have distinct melting rate. To determine behavior of recycled material at room temperature. Impact toughness and hardness tests are performed.

High capacity negative electrode materials such as silicon and germanium have been known to undergo massive volume change during lithiation/delithiation process. The large volume expansion in Si (~400%) and Ge (~280%) has been attributed to the fracture of the electrode materials, delamination from the current collector and losing contacts with the binder, resulting in rapid loss of capacity.1 Here we report our studies on the effects of particle size on the electrochemical performance of Ge electrode. Ge particles of different sizes (0.1-0.3, 0.3 -0.5, 0.8-1, >1 µm, ) are obtained by varying the time of ball milling and their capacity performances were measured by assembling a coin cell with the lithium metal as the counter electrode. The obtained results displayed the rapid capacity loss of the electrode with Ge particle size >1 µm, while the ones up to ~0.5 µm displayed significant stability. For the first 40 cycles tested, the Ge particles up to 0.5 µm retained ~90% of the initial charge capacity, and the ones with particle size 0.1-0.3 µm retained more than 95% of the initial charge capacity at the current density of 500 mA/g . For the Ge particle size > 1µm, the capacity retention even at the low current density of 100 mA/g at the end of 40 cycles was measured to be ~37%. This result demonstrates that above an optimum size, the Ge electrode exhibits rapid degradation of the performance. Further work is being carried out to determine the optimum size of the Ge electrode which yields a stable electrochemical performance. Fracture behavior of the Ge particles based on fracture mechanics will be reported. Theoretical analysis based on a rigorous continuum mechanics model will be used to extract critical size for Ge-based electrodes.

Effect of the type, size and concentration of solid lubricants on the tribological properties of the polymer PEEK

Biochar has attained significant attention as a beneficial soil amendment amongst growers and researchers. However, the impact of particle size of biochar is yet to be investigated. Here in the present study, we studied three particle sizes (<2 mm, 2–5 mm, and >5 mm) of biochar and two rhizobia strains (Rhizobium leguminoserum (RL) and Rhizogold (RG)) for their effect on the uptake and efficiency of nitrogen (N) in lentils. The two years experiment followed a randomized complete block design with split plot arrangement replicated three times. The data revealed that grain N, straw N, N uptake, N recovery efficiency (NRE), and N agronomic efficiency (NAE) were maximum with biochar smallest size (<2 mm). However, the N physiological efficiency, number of branches and plant height decreased with reduced particle size. Furthermore, the smallest particle size showed more number of pod plant−1. Biofertilizer strain (RL and RG) significantly increased the straw N but not the grain N. Both strains showed increased NRE and NAE, however, the RL demonstrated 7% more grain N than the RG. Both strains (RL and RG) demonstrated 16% and 20% increase in number of branches plant−1, 62% and 48% in plant height and 2% and 5% in root length, respectively. The RL strain improved the number of branches plant−1 at the lowest (<2 mm) and medium size (2–5 mm) particles size but both RL and RG strains demonstrated increased plant height under the maximum particle size. These results indicated that a mere increase in surface area with decreasing biochar particle size may not serve for enhancing biofertilizer strains performance since reducing particle size may immobilize the starter N applied. However, reducing particle size effect on N cycling into soil plant system was favorable.

ObjectiveThis experiment was conducted as a 3×2×2 factorial design to examine the effects of particle size (mean particle size of 331, 640, or 862 μm), evaluation method (direct vs indirect method) and adaptation duration (7 or 26 days) on the energy content and the apparent total tract digestibility (ATTD) of various chemical components in wheat when fed to finishing pigs.MethodsForty-two barrows (Duroc×Landrace×Yorkshire) with an initial body weight of 63.0±0.8 kg were individually placed in metabolic cages and randomly allotted to 1 of 7 diets with 6 pigs fed each diet. For the indirect method, the pigs were fed either a corn-soybean meal based basal diet or diets in which 38.94% of the basal diet was substituted by wheat of the different particle sizes. In the direct method, the diets contained 97.34% wheat with the different particle sizes. For both the direct and indirect methods, the pigs were adapted to their diets for either 7 or 26 days.ResultsA reduction in particle size linearly increased the digestible energy (DE) and metabolizable energy (ME) contents as well as the ATTD of gross energy, crude protein, organic matter, ether extract (EE) and acid detergent fiber (ADF) (p<0.05), and had a trend to increase the ATTD of dry matter of wheat (p = 0.084). The DE, ME contents, and ATTD of gross energy, crude protein, dry matter and organic matter were higher (p<0.05) when determined by the direct method, but the ATTD of ADF, EE, and neutral detergent fiber were higher when determined by the indirect method (p<0.05). Prolongation of the adaption duration decreased the ATTD of neutral detergent fiber (p<0.05) and had a trend to increase the ATTD of EE (p = 0.061). There were no interactions between particle size and the duration of the adaptation duration. The ATTD of EE in wheat was influenced by a trend of interaction between method and adaptation duration (p = 0.074). The ATTD of ADF and EE in wheat was influenced by an interaction between evaluation method and wheat particle size such that there were linear equations (p<0.01) about ATTD of ADF and EE when determined by the direct method but quadratic equations (p = 0.073 and p = 0.088, respectively) about ATTD of ADF and EE when determined by the indirect method.ConclusionDecreasing particle size can improve the DE and ME contents of wheat; both of the direct and indirect methods of evaluation are suitable for evaluating the DE and ME contents of wheat with different particle sizes; and an adaptation duration of 7 d is sufficient to evaluate DE and ME contents of wheat in finishing pigs.

As the bioconversion of cellulosic substrate to fuels is essential to suppress the dependence on conventional fossil fuels, development of new improved bioprocess engineering techniques are requisite for fulfilling the rising demand of biofuels throughout the world. For this purpose, the effect of particle size on enzymatic hydrolysis of cotton cellulose has been explored in great detail. The model simulations for the enzymatic hydrolysis of microcrystalline cotton cellulose of different concentrations (0.25-20mg/ml) were performed for the average particle size ranging from 0.78 to 25.52μm. A highest glucose yield (99.8%) was observed for the smallest particle size of 0.78μm in 50h of enzymatic hydrolysis. Effect of inhibition (competitive and non-competitive) on glucose yield was analyzed through the incorporation of product inhibition in the kinetic model. The extent of cleaving of 1-4 glycosidic bonds by cellulase was quantified by degree of polymerization (DP) of cotton polymers which also indicates that faster scission of bonds can be observed under competitive inhibition and, hence, more glucose yield. The model simulations shows that particle size reduction may be useful for reducing the long residence time required for the hydrolysis step in the bioconversion of cellulose to ethanol.

Effect of particle size and alkali activation on coal fly ash and their role in sintered ceramic tiles

Effect of doping and particle size on hydrogen absorption properties of BCC solid solution 52Ti-12V-36Cr

Nanosized In2O3 powders with different particle sizes were prepared by the microemulsion synthetic method. The effects of particle size on the gas-sensing and catalytic properties of the as-prepared In2O3 were investigated. Reductions in particle size to nanometer levels improved the sensitivity and catalytic activity of In2O3 to i-C4H10 and C2H5OH. The sensitivity of nanosized In2O3 (<42 nm) sensors to i-C4H10, H2 and C2H5OH was 2-4 times higher than that of chemically precipitated In2O3 (130 nm) sensor. A nearly linear relationship was observed between the catalytic activity and specific surface area of In2O3 for the oxidation of i-C4H10 and C2H5OH at 275 °C. The relationship between gas sensitivity and catalytic activity was further discussed. The results of this work reveal that catalytic activity plays a key role in enhancing the sensitivity of gas-sensing materials.

The present work aims to study the effect of particles shape and size of copper powder on physical, mechanical properties and wear resistance of copper-13vol%graphite composites prepared by powder metallurgy technique.Spherical and dendritic copper powder particles were used as a matrix besides a mixture of both shapes with three particle size ranges [(25>),(38-45),(53-63)]m. 13vol%graphite powder with a grain size of(63 (≤ was added as reinforcement. All powder mixtures were mixed mechanically for 2 hours. The mixed powders were cold pressed uniaxially at (700Mpa) for 30seconds and sintered at (900 oC) for one hour. The results showed that the relative density, both electrical and thermal conductivities and compressive strength of dendritic copper composites are higher than those of spherical copper composites, for example, the maximum values for both electrical and thermal conductivities for dendritic copper (53-63)m+13vol%graphite composite were 36.01 (.m)-1, 295.55 W/m.oK respectively, while wear rate of dendritic copper composites was lower than that of spherical copper composites where the minimum value for dendritic copper composites was (1.068×10-9 g/cm) for dendritic copper (53-63)m+13vol%graphite composite. It was found through the results of the present work that relative density, hardness and compressive strength increases with decreasing copper particle size. On the other hand an improvement in wear resistance was found on decreasing the particle size.

This paper reports the application of anthracite particles of different sizes and coated with nine kinds of layered double hydroxides (LDHs) varying in MII–MIII cations, as alternative substrates in the simulated vertical-flow constructed wetland columns. Effects of LDHs-coating and particle size of modified anthracites were examined to evaluate their abilities in removing oxygen demand and nitrogen from sewage wastewater. Results showed that LDHs modification effectively enhanced the removal of nitrogen and organics. The removal efficiencies of total nitrogen (TN) , ammonia and chemical oxygen demand (COD) were best improved by 28.5%, 11.9% and 4.1% for the medium particle size (1–3 mm), followed by 9.2%, 5.5% and 13.6% for the large size (3–5 mm), respectively. Only TN removal was improved up to 16.6% for the small particle size (0.5–1 mm). Nitrate tended to accumulate and fluctuate greatly across all the treatments, probably due to the dominancy of aerobic condition in the vertical-flow columns. Overall, MgFe-LDHs was selected as the best-modified coating for anthracite. The results suggested LDHs modification would be one of the promising strategies to provide new-types of highly efficient and lasting wetland substrates.

Particle size effects on the dosimetry characteristics of K3Na(SO4)2:Eu TLD micro- and nanophosphors