Effect Of Particle Properties Research Articles

Effects of particle properties, intermolecular forces, and molecular structure on the shear-thickening behavior of waxy starch dispersions

The shear-thickening phenomenon in waxy starch dispersions has been reported; however, the influence of starch properties on it remains unclear. Herein, the shear-thickening behavior of five waxy starch dispersions at different concentrations is investigated, and two shear-thickening areas are identified for the first time. Waxy potato and cassava starch dispersions present two shear-thickening areas, waxy maize and wheat starch dispersions exhibit one shear-thickening area, and waxy rice starch dispersion exhibits no shear-thickening behavior. Starches with high degree of polymerization (DP > 12 and > 37 chains), short-range order, relative crystallinity, melting enthalpy (ΔH), and low molecular weight easily form large particle fragments and strong intermolecular forces, thereby resulting in double shear-thickening areas. Starches with relatively high DP > 12 chains, short-range order, relative crystallinity, and ΔH form one shear-thickening area. Starches with no shear-thickening area have high molecular weight, degree of branching, and DP < 12 chains, and low short-range order, relative crystallinity, and ΔH. It can be speculated that the first shear-thickening area (2–5 s−1) is due to the presence of large particle fragments, whereas the second (10–15 s−1) is due to the interaction between the side chains of the starch molecule.

CFD study on the effect of particle properties on the performance of annular jet pump

Abstract The annular jet pump is a type of fluid mechanical pump that operates by exchanging momentum with the fluid. Annular jet pumps possess distinctive advantages in the transportation of solid particles. However, the efficiency of these pumps is significantly impacted by both the physical properties of the particles and their initial concentration, thereby limiting their practical applications. In this paper, by combining other scholars’ designs of annular jet pumps, the effects of different physical densities and different initial concentrations of particles on the flow field, pressure and efficiency of an annular jet pump were analysed based on the RNG k-ε turbulence model and the Mixture multiphase flow model. The efficiency of the annular jet pump decreases with a higher particle bulk density. Specifically, at an initial concentration of 20% and a flow ratio (M) of 0.5, the efficiency of the annular jet pump fluctuates as follows: it changes from 28.736% under single-phase flow conditions to 25.011%, 24.369%, 23.637%, 22.950%, and 21.733% as the density of particulate matter increases. The findings of this study offer valuable theoretical insights for the implementation of annular jet pumps in engineering discharge applications.

Erosion impact on slurry pump behavior and productive life: An experimental and Numerical investigation

ABSTRACT Normally, the characteristics of the main parts of a slurry pump that may be suffer from erosion under two-phase flow circumstances have been extensively and thoroughly researched. Whereas, the effect of particle properties on pump behavior or performance has been the subject of several studies; however, the current research focused on various methods for reducing slurry erosion utilizing recent research methods. Thus, the analysis and investigation for various pressure distributions, velocity, erosion-rate, and vortex structure were carefully demonstrated in this study. In addition, the slurry pump’s wear or erosion characteristics were carefully examined, and it was found that as the flow rate increases, the wear of the suction surface worsens. As a result, the key findings of this research might offer the ideal guidance for optimum design and the right strategies for erosion protection for any slurry flow through centrifugal pumps.

Assessing the formation and destruction behaviors of fine powder agglomerates in vibrating fluidized beds using the Ergun equation

The recycling and reutilization of powdery/dust waste are becoming increasingly important for ensuring a sustainable environment and decreasing the cost of waste disposal. In this regard, we examined component separation using a vibrating fluidized bed based on the differences in the agglomeration properties of the particles of each component. In the proposed separation method, the knowledge of agglomerate formation and destruction in a fluidized bed is essential. In this study, the effects of particle properties on agglomerate formation and destruction in a vibrating fluidized bed were investigated. Rutile and anatase titanium oxide and zinc oxide were used as test powders. The changes in the powder layer height and pressure drop were recorded. The results were utilized to compute the changes in the agglomerate size using the Ergun equation, and agglomerate formation and destruction were evaluated. Furthermore, the relationship between the equilibrium agglomerate size and vibration intensity was investigated.

Numerical and experimental investigations on the effect of particle properties on the erosion behavior of aluminum alloy during abrasive air jet machining process

Numerical and experimental investigations on the effect of particle properties on the erosion behavior of aluminum alloy during abrasive air jet machining process

An investigation on pickering nano-emulsions stabilized by dihydromyricetin/high-amylose corn starch composite particles: Preparation conditions and carrier properties

With dihydromyricetin (DMY)/high-amylose corn starch (HCS) composite particles as the emulsifier, Pickering nano-emulsions were fabricated by combining high-speed shearing and high-pressure homogenization. The effect of particle properties and processing conditions on the formation and physicochemical properties of the Pickering nano-emulsions was then investigated systematically. The results showed that the DMY content of the composite particles, the oil phase volume fraction of the emulsion, and the homogenization conditions had obvious effects on the droplet size of the emulsion, where appropriate DMY content in the composite particles (5–20%) contributed to the formation of stable Pickering nano-emulsions. The oil phase of the obtained emulsions exhibited good stability during high-temperature storage, and their β-carotene protecting performance against UV irradiation was superior to the emulsion stabilized by Tween 20. The in vitro simulated digestion analysis indicated that the nano-emulsions developed by the composite particles could enhance the bioaccessibility of β-carotene and inhibit starch hydrolysis.

Aggregation Kinetics of TiO2 Nanoparticles in Human and Artificial Sweat Solutions: Effects of Particle Properties and Sweat Constituents.

Dermal penetration potentials of titanium dioxide nanoparticles (TiO2 NPs) may be affected by aggregation upon contact with sweat. This study investigated the aggregation kinetics of three TiO2 NPs in thirty human sweat samples and four artificial sweat standards. Effects of particle concentration, sweat type, and inorganic (sodium chloride, disodium hydrogen phosphate, and sodium dihydrogen phosphate) and organic (l-histidine, lactic acid, and urea) constituents were examined. Three TiO2 NPs remained colloidally stable in >20/30 human sweat samples and showed significant negative correlations (P < 0.01) between aggregation rates and |zeta potentials|. They aggregated rapidly over 20 min to >750 nm in three artificial sweat standards, while remained more stable in the International-Standard-Organization-pH-5.5 standard. Aggregation behaviors of three TiO2 NPs mostly followed the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, allowing for determining their critical coagulation concentrations in inorganic constituents (15-491 mM) and Hamaker constants (3.3-7.9 × 10-21 J). Higher concentrations of particles, inorganic constituents, and l-histidine destabilized three TiO2 NPs, whereas urea inhibited aggregation. Three TiO2 NPs adsorbed organic sweat constituents via complexation with amino or carboxyl groups, with isotherms following the Langmuir model. Correlation analyses further suggested that the adsorbed organic constituents may stabilize three TiO2 NPs against aggregation in sweat by steric hindrance.

Compressive properties of the magnesium matrix syntactic foams using different types of porous volcanic rock particles

The novel magnesium matrix syntactic foams were successfully fabricated by using two types of porous natural volcanic rock (VR) particles as reinforcements. The effects of particle properties and testing temperature on the mechanical properties and energy absorption characteristics of the syntactic foams were systematically investigated. The obtained syntactic foams have good quality, high specific compressive properties at different temperatures. Two types of VR particles have different densities, morphologies, compositions and crushing strengths, inducing obvious contrasts in apparent density, mechanical properties and energy absorption characteristic of two kinds of syntactic foams. The syntactic foams containing high-density VR (HD-VR/Mg) have superior compressive strength, plateau strength and energy absorption capacity, while the syntactic foams containing low-density VR (LD-VR/Mg) exhibit lower density (0.89 g/cm3), higher porosity (49.5%) and more stable deformation behavior. At room temperature (RT), the failure of HD-VR/Mg syntactic foams is mainly controlled by shear fracture mode; in contrast, the failure of LD-VR/Mg syntactic foams is mixed modes. In addition, the compressive properties and energy absorption capacity of syntactic foams are depending on testing temperature. The compressive strength, plateau strength and energy absorption capacity of both syntactic foams gradually decrease with increasing temperature. The corresponding dominant failure mechanism of VR/Mg syntactic foams shifts due to the increased plasticity of Mg struts with increasing temperature.

Study on flow characteristics of bidirectional sinusoidal liquid pulsed gas-liquid-solid multiphase fluidized bed

Gas-liquid-solid three-phase fluidized bed has been widely used in chemical, biotechnology and environmental industries for its advantages of large inter-phase contact area, high heat/mass transfer efficiency and intense reaction process. In this work, the bidirectional sinusoidal liquid pulsed GLS fluidized bed was proposed to improve the interphase relative velocity and reaction efficiency. The effects of particle properties and pulsed liquid amplitude/frequency on the flow characteristics were studied by numerical simulations and experiments. In a complete circulation period, the average axial solids holdup is larger near the middle region of the fluidized bed and gradually decreases along the upper and lower inlets. With the increase of pulsation amplitude or period, the axial average gas holdup distribution uniformity and the liquid-solid relative velocity increase significantly. Compared with the conventional upward gas-liquid-solid fluidized bed, the bidirectional fluidized bed can further improve the liquid-solid relative velocity and reaction efficiency. The obtained studies have important implications for better design, scale-up and operation of gas-liquid-solid multiphase fluidization systems.

Effect of Particulate Properties of Inhaled Dry Powder Formulation on Bioavailability, Dissolution Rate of Drug Particles and Rate of Drug Removal from the Body

Introduction: The use of pulmonary drug delivery as a non-invasive drug delivery system for the systemic treatment of diseases as well as the topical treatment of respiratory diseases is increasing. Among the various inhaled formulations, inhaled dry powders show advantages over the other forms of inhaled medicines due to high stability, bioavailability and ease of use. The effect of particle properties on the rate of drug delivery to the lungs in inhaled dry powders has been investigated in previous papers.&#x0D; Conclusion: Since the physicochemical properties of particles of dry powder inhalation formulations such as particle size, surface and particle shape, as well as the electrical charge of the particles play a decisive role in drug pharmacokinetics, in the present review article we intended to discuss the effect of these parameters of inhaled dry powder formulations on bioavailability, dissolution rate of drug particles and the rate of drug clearance from the body.

Hydrodynamic Analysis of Tidal Current Turbine under Water-Sediment Conditions

The rivers connecting oceans generally carry sediment due to water and soil losses in China. Additionally, the maximum sediment concentration is 300 g/L, which is much higher than that of other countries. It is unknown whether seawater with sand particles will affect the power of tidal current turbine blades. It is therefore necessary to study the capture power of tidal current turbines in the water-sediment environment. In this study, the blade was divided into a number of transversal airfoil elements based on the blade element theory. The CFD-DPM model was employed to study the lift and drag coefficients of airfoil under multiphase flow, and the fluid–particle interaction was considered. The accuracy of this presented model was assessed using the experimental data of a 120 kW tidal current turbine in a water-sediment environment. Good agreement between the predictions and experimental data was observed. The effect of particle properties on the lift coefficient and the drag coefficient of airfoil were investigated in detail. Furthermore, the 120 kW tidal current turbine power was calculated based on the Blade Element Momentum theory under different particle concentrations. The results show that small diameter particles can improve the tidal current turbine power and the large diameter particle can reduce the power.

Anisotropy in small-strain shear modulus of granular materials: Effects of particle properties and experimental conditions

Granular soils display directional diversity in stiffness at small strains, which is essential for geotechnical engineering design and can be reflected by the anisotropy of small-strain shear modulus G0. However, the understanding of the stiffness anisotropy of soils is still limited. This contribution presents a series of shear (S-) wave propagation tests using cubical specimens and planer piezoelectric transducers, and discusses the effects of the intrinsic particle properties and experimental conditions on the G0 anisotropy. Four granular materials: spherical glass beads, Toyoura sand, basmati rice, and wild rice are prepared densely in a dry condition and tested under both K0 and isotropic stress states. The experimental results reveal that the particle shape and particle orientation after deposition can affect the anisotropy of the S-wave velocities (Vs), and thus, G0. Tests with different granular materials show that a more elongated particle shape can induce larger anisotropy in G0. From the results of tests on the wild rice specimens, Vs is found to be higher when the major axes of the particles coincide with the direction of the wave propagation, compared to the situation when the major axes are parallel to the oscillation direction of the S-wave. Among the six components in the principal directions, the S-waves neither propagating nor oscillating along the particle orientation are the slowest. Considering the experimental conditions, a mix of flexible (membrane) and rigid boundaries tends to induce larger anisotropy in G0 and a measurable difference between symmetric shear moduli Ghv and Gvh, while the effect of the specimen aspect ratio is less significant.

Hydrodynamics in a new liquid–solid circulating conventional fluidized bed

A new type of liquid–solid fluidized bed, named circulating conventional fluidized bed (CCFB) which operates below particle terminal velocity was proposed and experimentally studied. The hydrodynamic behavior was systematically studied in a liquid–solid CCFB of 0.032 m I.D. and 4.5 m in height with five different types of particles. Liquid–solid fluidization with external particle circulation was experimentally realized below the particle terminal velocity. The axial distribution of local solids holdup was obtained and found to be fairly uniform in a wide range of liquid velocities and solids circulation rates. The average solids holdup is found to be significantly increased compared with conventional fluidization at similar conditions. The effect of particle properties and operating conditions on bed behavior was investigated as well. Results show that particles with higher terminal velocity have higher average solids holdup.

Hydrodynamics of inverse liquid-solid circulating fluidized bed

Hydrodynamics of inverse liquid–solid circulating fluidized bed (ILSCFB) is comprehensively studied with five types of low-density particles in a long experimental column of 5.4 m tall. The flow patterns observed mirror those of upright LSCFB under similar conditions. Axial distribution of solids holdup is uniform and radial solids holdup is also generally uniform but with some dilute region existing near the wall. The average solids holdup increases with Us while decreases with Ul. The effect of particle properties on the fluidization appears to be less extensive. The relationship between slip velocity and solids holdup in ILSCFB and inverse conventional fluidized bed is different. Clustering effect in liquid–solid circulating fluidized beds is first investigated. Particles with small particle Reynolds number tend to have more severe clustering as shown by the higher slip velocity. A modified Richardson-Zaki equation is developed for the prediction of solids holdup in inverse liquid–solid circulating fluidized bed.

Effects of Particle Properties on Visualizing Flows in a Two- Stage Electrostatic Precipitator Using Particle Image Velocimetry

The amount of particulate matter (PM) in the environment has been confirmed to be health risks on human bodies[1, 2], and therefore removing suspended particles has become the research goal of many studies. Electrostatic precipitator (ESP) is one of the high-efficiency particle collection technologies[3-7]. Particle Image Velocimetry (PIV) has been an effective tool for visualizing the flow patterns in experimental fluid mechanics, and many studies adopted this technique to study flows in ESP[8-10]. However, particles charged by the electric field can cause deviation in measurement results since it does not follow the ionized air flow which can be charged differently from the tracer particles. In this study, the observation of the effects of different particle properties on flow field in a two-stage ESP is the objectives of this study. A two-stage ESP was built and four different seeding particles, aluminum oxide (Al2O3) particle, oil droplet particle, sodium chloride (NaCl) particle, and titanium dioxide (TiO2) particle, are tested in the current study. In this study, the streamwise velocity of the flows ranges from 2.36 m/s to 4.18 m/s, the voltage of the corona electrode varies from 8 kV to 12 kV with a positive polarity, and the voltage of the collector electrode is fixed at 16 kV. To investigate the 3-D flow patterns inside the channel, data at different planes were taken for comparison. The results show that by increasing charge voltage from 8 kV to 12 kV with a streamwise flow velocity the 2.36 m/s, the y-component velocity for Al2O3 particle, oil droplet particle, NaCl particle and TiO2 particle increased by 50.6%, 76.0%, 33.5% and 51.9%, respectively. Moreover, for the case of the 4.18 m/s primary flow, the y-component velocity for Al2O3 particle, oil droplet particle, NaCl particle and TiO2 particle increase by 52.7%, 59.2%, 59.4% and 65.9% after the voltages increase from 8 kV to 12 kV. PIV results for oil droplet particle shows slower y-component velocities, which can be due to the lower Archimedes number of 3.12E-06 and the mobility number that is larger than 3. On the contrary, in most of results from TiO2 particles show high y-component velocity, which is due to the highest Archimedes number of 1.15E-03 of the seeding particles tested in this study. This result shows that the particle is less affected by buoyancy effect. The PIV results of the middle plane also shows that the ycomponent of velocity from -2.6 m/s to -0.5 m/s, in contrast to -1.0 m/s to 1.0 m/s from the near wall observation plane. These results are consistent to simulation results of the electric field distribution, whichshows unequal electric field strengths between the middle and near wall regions of the test section. Only half of the cage shape distribution of the electric field can be observed, and primary flow influences the ionic wind to move to the downstream area. Based on the results, the oil droplet and TiO2 particles are more suitable for the role of tracer particles compared to aluminum oxide and sodium chloride particles.

Experimental Investigation of the Attachment Performance between Coal Particle and Bubble.

Attachment behavior is a key component of flotation and has a decisive influence on flotation performance, and the experiment research on the attachment between mineral particles and bubbles still needs further research. In this work, a particle–bubble attachment apparatus and multiple target tracking software were developed. Coal particles were used as the subjects, and the effect of particle properties on the attachment performance was studied from the perspective of the particle group. The particle–bubble attachment experiments indicated that the collision position had an effect on the attachment efficiency, and the attachment efficiency decreased with an increase in the collision angle. The efficiency-weighted attachment angle was proposed to quantitatively describe the attachment performance of coal samples. The efficiency-weighted attachment angle of low-density coal samples was greater than that of high-density coal samples. For particles with different sizes, the efficiency-weighted attachment angle of fine particles was greater than that of coarse particles. Furthermore, SDS weakened the attachment performance between coal particles and bubbles via adsorption on the bubble, and the efficiency-weighted attachment angle decreased as the concentration of the SDS solution increased. CTAB adsorbed on coal particles and bubbles, and the efficiency-weighted attachment angle first increased and then decreased with increasing CTAB concentration.

Demarcation on a new conventional circulating fluidization regime in liquid-solids fluidization via experimental and numerical studies

A new type of liquid-solid circulating fluidized bed, the conventional circulating fluidized bed (CCFB), which operates at superficial liquid velocities below the particle terminal velocity (Ut), was delineated through experimental and numerical studies, in both upward and inverse liquid-solid fluidization systems. The CCFB system was essentially operated in the conventional fluidization regime but with continuous feeding of particles into the liquid inlet end of the fluidization column and particles moving along with the liquid to the other end of the column to achieve solids circulation or circulating fluidization. An extended operating window of the CCFB was numerically studied using the Eulerian-Eulerian two-fluid model based on the existing experimental data. The effects of particle properties and operating conditions on the CCFB were studied. The hydrodynamics in the CCFB were also compared with that in a circulating fluidized bed (CFB). An inverse CCFB using particles with a density lower than the liquid was also investigated by simulations and compared with the upward CCFB. A new flow regime referring to the CCFB operating mode for the liquid-solids fluidization systems, both upwards and inverse, was proposed and situated in between the conventional and circulating fluidized beds.

Effect of particle properties on rheology of low-concentration coal suspensions

Effect of particle properties on rheology of low-concentration coal suspensions

Fluid Dynamic Analysis of a Modified Mechanical Stirring Spouted Bed: Effect of Particle Properties and Stirring Rotation

The purpose of this study is to perform the fluid dynamic analysis of a modified mechanical stirring spouted bed, which has been proposed as a promising alternative to the conventional spouted bed....

The effect of particle properties and solids concentration on the yield stress behaviour of drilling fluid filter cakes

Filter cakes made from model water-based drilling fluids were tested to determine cake properties such as porosity, thickness and yield stress. The effects of drilling fluid particle concentration, size distribution and shape on the properties of the resulting cakes were investigated. A hole punch tester was used to find the shear stress of the cakes, obtaining a yield stress from the measured peak force. The cake yield stress increased with increasing barite solids content in the fluid from 16.5 kPa at 3.1 vol% to 65.6 kPa at 24.8 vol%. A similar trend was observed for cakes made from calcium carbonate. Furthermore, the calcium carbonate cakes were thicker and stronger than the barite equivalents, with yield stresses increasing by between 29% and 56%. The addition of calcium carbonate particles to the existing barite network did not affect the cake thickness appreciably but gave cakes of lower porosity and higher yield stress.