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In this paper, numerical simulations of experimental data were performed with kinetic rate coefficients to characterize the retention and re-entrainment dynamics under different hydrodynamic conditions for monodisperse and polydisperse latex particles (3, 10, 16 μm and the mixture). The results show that drastic increase in fluid velocity provokes hardly any remarkable decrease in retention in the presence of large energy barriers (> 2000 kT). Systematical increases in deposition and re-entrainment dynamic rates were observed with fluid velocity and/or particle size. Increased irreversible deposition rate indicates straining and wedging dominate deposition in this study. Excess retention of 3 μm particle in the polydisperse particle suspension was observed. The origins are reckoned that deposited larger particles may hinder the re-entrainment of smaller particles near the grain-to-grain contact and can provide additional sites of attachment.

The evolution of suspension drops settling in a fluid at low to moderate Reynolds number (based on drop sizes) is investigated experimentally. With increasing Reynolds number, it is found that the shape of the drop changes more rapidly with traveling length before breakup decreases. Also, the aspect ratio of the drop at breaking up, and the number of secondary droplets after breaking up increase with the Reynolds number. Our findings are consistent with previous simulation studies. The evolution and breakup mechanisms of a settling suspension drop at low to moderate Reynolds number are different to those at creeping flow limit.

Despite advances in drug technology and improvements in technology, including peripheral nerve catheters and ultrasound, postoperative pain is still a significant problem in the clinical setting worldwide. Postoperative pain can have a critical negative impact with regard to physiological consequences to the body and therefore, the role of liposomal bupivacaine as an extended release bupivacaine with approximately 72 h of duration may have far-reaching and significant impact in clinical practice. Liposomal bupivacaine has a DepoFoam multivesicular liposome technology with particle suspension in an isotonic aqueous solution and consists of tiny lipid-based particles, which contain discrete water-filled chambers dispersed through a lipid matrix. Other advantages include a reduction in opioid consumption, while not requiring a catheter or any other device, as well as easy dilution with saline. This review summarizes current research with this novel agent in postsurgical pain, and discusses potential roles in chronic pain states. Further studies are warranted for its use in epidural and intrathecal administration. Moreover, this review will explore the expansion of liposomal bupivacaine's current clinical role.

A quantitative methodology for particle suspension assessment is presented. A new parameter, fmov/tot, the ratio of the mean number of moving particles to the total number of particles, is introduced to evaluate the minimum speed required to just suspend solids. This approach is tested to investigate the impact of impeller clearance on the minimum impeller speed, Njs, in a vessel when using a radial flow Rushton turbine. Flow patterns and power numbers obtained experimentally and computationally support the suspension findings. Image analysis is an appropriate method for determining Njs. Lowering the impeller clearance reduces the speed required for particle suspension with a change of flow pattern from a radial discharge with two loops to a single loop scouring the vessel base. The power number also falls markedly at the two-to-one loop transition as does the strain rate near the base.

We report the manufacture of complex structures of silica, coal or sphalerite particles around a water droplet, driven by an electrostatic field. A particle bed was deposited on an electrically biased substrate and an earthed water drop brought close, such that the particles jumped to the drop. These structures' shape and internal composition were determined by a combination of the particles' wettability and electrical properties, and other attributes such as shape, size and density were also thought to play a role. Hydrophilic particles tend to be internalised by the drop, while hydrophobic ones tend to form a layer or shell on the surface. Thus, one example of these structures was a ‘complex liquid marble’, with a hydrophilic particle suspension core and a stabilising shell of hydrophobic particles.

The magnetization induced by oscillatory magnetic-field in a polydispersive superparamagnetic-suspension shows a nonlinearity which strongly depends on the applied frequency. Referring to the initially-measured complex magnetic-susceptibility in function of field-strength, the highly-nonlinear curve of dynamic magnetization at low frequency tends to be linear at higher frequency. Likewise, the dynamic susceptibility appears to be less field-strength dependent at higher frequency, emphasizing a frequency-dependence of magnetically-induced particle-dynamics. This finding is attributable to the imaginary part of magnetization which saturates at lower field-strength of low-frequency magnetic-field. Hence, Brownian relaxation losses should be constant after the saturation due to a confinement of particle rotations.

The homogenization of the agitated batch and ensuring the suspension of particles are the most frequently encountered requirements in terms of mixing applications. These operations are affected by the flow of the agitated batch. The geometrical parameters of the mixing system, especially the shape of the agitator blade, affect flow and circulation in the agitated batch. The present work provides a general description of the most common processes in the agitated batch (blending and particle suspension), hydrodynamic parameters (flow in agitated batches, pumping and circulation capacity of impellers) and the geometrical configurations of the mixing equipment (shape of vessel, baffle and impeller, and their mutual arrangement) that influence the process. The dimensionless process characteristics of the agitator were derived by theoretical analysis. These characteristics were applied to evaluate an extensive set of experimental data with various geometric configurations of the mixing equipment. This study shows how the flow in the agitated batch, caused by the pumping and circulating effects of the agitators, affects the parameters and energy efficiency of these processes, depending on the geometric configuration of the mixing equipment. Moreover, the benefits of the hydrofoil impellers used for these mixing processes are presented.

Gas nuclei in water are usually too small to be directly observed. They will grow into bubbles under the negative pressure, which is called cavitation (heterogeneous cavitation). In this study, the gas nuclei in the hydrophilic and hydrophobic silica particle suspension were investigated using the transient cavitation threshold measured by a high-intensity focused ultrasound (HIFU). The transient cavitation bubbles were also observed by a high-speed camera. The results showed that the nuclei only exist on the surface of hydrophobic particles. Furthermore, the aggregation experiments revealed that the aggregates were only formed in the hydrophobic silica suspension by ultrasonic standing waves (USW) at 200 kHz. This distinct difference was mainly due to the formation of gas nuclei on hydrophobic silica particles, which grew and coalesced into stable bubbles under the 200 kHz USW. The aggregation process in suspension was observed by a CCD camera. Moreover, the cavitation thresholds and acoustic radiation forces were analyzed to explain the mechanism of the acoustic aggregation. This study showed a very promising acoustic method for the selective aggregation of hydrophobic particles, which might be efficiently used in the mineral separation industry.

We have proposed a new repulsive layer model for describing the interaction between steric layers of coated cubic particles. This approach is an effective technique applicable to particle-based sim...

A two dimensional (2D) boundary layer two-phase MHD (magneto hydrodynamics) flow of Maxwell and Oldroyd-B fluid over a stretching sheet has been explored. Heat and mass transfer phenomena is inspected through Non-linear radiation, viscous dissipation, joule heating, Soret (thermo-diffusion) and Dufour (diffusion-thermo) Impact. The boundary layer governing differential equations are modelled and transformed to a system of ODE’S with the aid of similarity transformations. The final controlled equations along boundary restrictions are resolved numerically by Runge-Kutta Felhberg method. The graphical analysis has been emphasized for the fluid and dust phase velocity, temperature and concentration fields to the influence of sundry dynamical flow quantities. Furthermore, for authentication of the present computation, the achieved results are distinguished with earlier research works in specific cases and marvellous agreement has been noted. The outcomes conveyed here manifest that velocity and boundary layer thickness escalate with boost up the values of ${K_1}$ . Velocity and boundary layer thickness declines with boost up the values of $M$ . Opposite trend is seen in temperature and concentration profiles. The specific heat ratio parameter $\gamma$ enhances the temperature profile declines. Boost up the values of Soret number $Sr$ temperature profile declines and concentration profile enhances. Skin friction factor declines with increasing values $\beta _v$ verses $M$ .

© 2018 The key to achieve an economically more attractive concentrated solar power plant is to work at higher operating temperatures, allowing both higher power conversion efficiencies resulting in a smaller heliostat field for a given energy output, and higher temperature ranges in the storage tanks, with increased energy storage density and smaller size, hence less expensive. This fostered the development of using particle suspensions as heat transfer media. This paper presents a theoretical framework for the energy analysis of a particle-in-tube solar power plant, hybridized, with topping air-Brayton cycle turbine, and bottoming steam block. From studying the effects of essential design parameters on the energy efficiency, the heat transfer efficiency of the turbine air preheater is of paramount importance to increase the solar contribution within the hybrid concept, while the energy efficiency moreover increases by an optimum air-Brayton cycle turbine operation (mostly through the pressure ratio, less by the operating temperature). The overall efficiency of the concept varies from about 40% when using combined low and high pressure Brayton cycle turbines only, to over 48% in a fully combined air-steam concept. Energy efficiency findings are in agreement with the literature data. ispartof: ENERGY CONVERSION AND MANAGEMENT vol:163 pages:292-303 status: published

This study characterized the generation of windblown dust from various sources in the Athabasca Oil Sands Region (AOSR) in Alberta, Canada. The Portable In-Situ Wind Erosion Laboratory (PI-SWERL) equipped with two real-time dust monitors and nine-channel filter packs was used to simulate wind-driven erosion and measure emissions. Sixty four sites were measured, including oil sands mining facilities, quarry operations, and roadways in the vicinity of Ft. McMurray and Ft. McKay. Key parameters related to windblown dust generation were characterized including: threshold friction velocity, reservoir type, and particle size-segregated emission potential. The threshold wind speed for particle suspension varies from 11 to 21.5 km/h (u10+; measured at 10 m above ground level), and saltation occurs at higher speeds of u10+ >32 km/h. All surfaces have limited dust supplies at lower wind speeds of

A dense particles suspension was tested in a high temperature single tube on-sun solar receiver at the French National Centre for Scientific Research (in French: Centre National de la Recherche Scientifique = CNRS) solar facility. A powder outlet temperature as high as 750 °C was measured thus proving the capacity of this heat transfer fluid concept to reach high operating temperatures. The wall-to-suspension heat transfer coefficient was calculated on the basis of detailed temperature measurements and accounting for the strong recirculation phenomena occurring at the tube wall. It ranges from 420 W/m2 K to 1100 W/m2 K for a solid mass flux of 10 kg/m2 s and 45 kg/m2 s, respectively. The temperature increase positively influences the heat transfer coefficient; with a 30% increase measured between ∼200 °C and 600 °C average powder temperatures. Finally, a correlation is proposed to predict the dependency of the heat transfer coefficient and solid mass flux.

The gelation of FeOOH rod particles in a glycerin-water mixture under shear flows is investigated using rheological measurements. The average length and the average diameter of the rod particles are 1 μm and 120 nm, respectively. The van der Waals energy is much larger than the Brownian and electrostatic contributions. To examine the effect of shear history on gelation, two different kinds of experimental procedures are used: A strong, but short preshear followed by a creep test and a preshear for a long time followed by a creep test. The rod particle suspension becomes a gel during the creep test showing the plateau in G′ and yield stress. The gelation time during the creep test is dependent on preshear time while it is not affected by the preshear stress for a short time before the creep test. Both the plateau in G′ and the yield stress are larger when the preshear time is longer. The gelation appears to occur by two steps of the formation of flocs by the aggregation of individual particles and then the formation of the sample spanning network by the aggregation of the flocs. Gel strength appears to be dependent on floc size which is determined by the imposed shear stress in the present case of shear induced gelation.

This study examined experimentally the characteristics of the flow pattern and particle suspension in an agitated vessel with a bottom baffle. A flow pattern of the particles was shown to increase the upward flow from the center of the agitated vessel bottom. The suspended particles from the experiment found that the particle suspension was promoted by the development of an Ekman boundary layer. The optimal conditions of the impeller, and the agitated vessel bottom baffle within the experimental range were as follows: Impeller,  = 6,  = 0.5 and  = 0.3; and bottom baffle,  = 6,  = 0.5 and  = 0.05

Formation of low permeable external filter cake during drilling and water injection has been widely reported in the literature. It may cause significant decrease in well index. The process is very sensitive to size distribution of injected particles. We propose a new mathematical model for cake formation with deep bed filtration for two-particle-size injection. The basic equations account for three stages: formation of cake from large particles with simultaneous deep bed filtration of small particles; small particle capture in the cake with formation of the internal cake inside the external cake; build-up of the uniform cake from the mixture of two-size particles. The analytical model is derived for three stages. Two regimes of the cake formation are identified, which correspond to the high and low concentrations of injected small particles. The laboratory coreflood with two-particle-size suspension injection with monitoring the rate and pressure drop along the core is performed. The matched mathematical model shows good agreement with the laboratory data.

In order to investigate the stability limit and movement of motor vehicles in tsunami flooding,and the drift andcollision behavior to the tsunami evacuation tower, both physical and numerical model experiments have been carried out. For the numerical study, Ladd's Lattice Boltzmann Method (LBM) model for particle suspension, which has been extended with free surface and SGS turbulence model, is further modified to satisfy the simulations of motor vehicles with irregular shape. The interactions between fluid and vehicle body, and vehicle and vehicle are numerically simulated by the exchange of momentum, due to the application of link-bounce-back scheme for the movable solid particles in the fluid.The present numerical model is verified through the physical experiments using up to 80 car models.

Several studies have proved that a significant electrorheological (ER) effect can be obtained by using particles with hierarchic structures as the dispersing phase. The inter-particle friction and fluid friction caused by the rough surface of the particles plays an important role for their enhanced ER effect. However, the detailed contribution of friction to ER properties remains unclear. We prepare two different ER fluids with chrysanthemum-like particles and spherical particles, respectively. We carry out a low shear velocity oscillation test to separate the friction-induced shear stress from the electrostatic attraction-induced shear stress. The chrysanthemum-like particle-based ER suspension presents much better ER performance than the ER fluid with spherical particles. The larger friction force caused by the rougher surface of the chrysanthemum-like particles is a major reason for the improvement. The contribution of friction to the ER effect depends on the electric field strength. The contribution has a maximum value at a critical electric field.

Slot coating is used in the manufacturing of functional films, which rely on specific particle microstructure to achieve the desired performance. Final structure on the coated film is strongly dependent on the suspension flow during the deposition of the coating liquid and on the subsequent drying process. Fundamental understanding on how particles are distributed in the coated layer enables optimization of the process and quality of the produced films. The complex coating flow leads to shear‐induced particle migration and non‐uniform particle distribution. We study slot coating flow of non‐colloidal suspensions by solving the mass and momentum conservation equations coupled with a particle transport equation using the Galerkin/Finite element method. The results show that particle distribution in the coating bead and in the coated layer is non‐uniform and is strongly dependent on the imposed flow rate (wet thickness). Fil: Campana, Diego Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Valdez Silva, Luis D.. Pontifícia Universidade Católica do Rio de Janeiro; Brasil Fil: Carvalho, Marcio S.. Pontifícia Universidade Católica do Rio de Janeiro; Brasil

In the present study, data that has been collected on the ballistic penetration of a dense particle suspension is examined using a simple analytical penetration model, treating the penetration process as a shear-failure plugging of the suspension, building on previously published models for the fluid. Through measurement of the incident and residual velocities of the projectile penetrating through the suspension, an estimate of the effective measure of the resistive strength of the suspension is made. The variation of this dynamic strength parameter as a function of the incident velocity of the projectile is used to discuss the penetration process within the fluid. The strength parameter is also used for comparison to values obtained for various materials, showing that a silica-based shear thickening fluid is not ideal for ballistic applications due to its low dynamic strength.

The effects of temperature and low-volume concentration on the dynamic viscosity of the Al2O3/water and Al2O3/ethylene glycol/water nanofluids are investigated. Nanofluids were prepared and characterised. Data were collected for temperatures ranging from 25 to 80°C. The presence of aggregated Al2O3 nanoparticles in the fluid, with average diameter of 109 nm which is ∼8 times the primary diameter (13 nm) of Al2O3 nanoparticles was witnessed. Furthermore, only at temperature below 40°C water-based alumina nanofluid at 0·05% v/v showed Newtonian behaviour. On the other hand, Al2O3/ethylene glycol/water mixture exhibited Newtonian behaviour. Results clearly showed the presence of a critical temperature, beyond which the particle suspension properties were noticed to be radically changed, which results in activating the hysteresis phenomenon. The hysteresis phenomenon on viscosity measurement, which is believed to be the first observed for ethylene glycol/water-based nanofluids, has raised serious concerns reg...

The influence of the suspension of positive active mass particles in the electrolyte on the performance of the negative electrode in a lead-acid battery is studied. A significant increase in the rate of corrosion of the lead electrode is shown when slime particles get in contact with its surface, which may result in the rise of macro-defects on the lugs of the negative electrodes.

The separation efficiency of the flotation process depends not only on differences in the physico-chemical surface properties of various minerals within an ore but also on the hydrodynamics of flotation. The aim of this article was to study the effects some fundamental hydrodynamic variables such as impeller speed on coarse particles flotation using a combination of factorial and one factor at a time experimental methods. As a function of impeller speed, the most important variable according to the factorial experiments, coarse-particle recovery increased with a Reynolds number around 119600, a Froude number of 1.53, and an air capacity number of 0.00346 and then decreased significantly due to the domination of the detachment mechanism in the process. Impeller clearance off-bottom was the second most important parameter and it was found that increasing impeller clearance off-bottom declined recovery as a result of decreasing the intensity of particle suspension. Frother concentration was the third most im...

The determination of the critical particle size between solid and fluid phases, i.e., the suspension competence, is fundamental for debris flow. A method for determining suspension competence based on particle size analysis is presented in this paper. Suspension competence of static experimental water-debris mixtures prepared with the sediment of Jiangjia Gully is 0.025 mm if the bulk density is less than 1,800 kg m-3 and it increases with bulk density of more concentrated mixtures. Suspension competence of natural debris flows in Jiangjia Gully increases exponentially with the bulk density. These two data sets are compared in order to understand the suspension mechanism It is concluded that turbulence may play a leading role in particle suspension in non-viscous and sub-viscous debris flows, while in viscous debris flows both matrix strength and excess pore water pressure play important roles.

Multivariate data analysis (MDA) is a well-established technique for abnormal situation management and early event detection (EED). This paper presents the development and on-line deployment of a Principle Component Analysis (PCA) model based EED system for an industrial-scale slurry stripper processing a solid state particle suspension. The developed solution was designed to detect plugging or blockage of the stripping column trays earlier than it is possible using traditional monitoring techniques and to avoid process disruption and production losses. The paper describes the project steps from data selection and preparation to the online implementation and utilization by operators and plant personnel. It was developed within a close collaboration between university and industry.

From recent issues of stability, particle suspension, particle segregation, flow characteristics and cohesiveness in concrete, Superplasticizer has played an important role in this part. This research examined the effect of superplasticizer on workability and properties of self-compacting concrete (SCC). Three types of superplasticizers Conplast SP 561, Conplast SP 430 and Conplast SP 264 at different percentages (0, 10, 20 and 30%) with the same water cement ratio of 0.3, with M30 grade of concrete. The workability slump, v-funnel and l-box the test carried out on fresh concrete. Compressive strength test was carried out on the hardened concrete. All mix were satisfactory but the mix with conplast SP 430 had better workability and strength.