scholarly journals Inertial and viscous flywheel sensing of nanoparticles

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Georgios Katsikis ◽  
Jesse F. Collis ◽  
Scott M. Knudsen ◽  
Vincent Agache ◽  
John E. Sader ◽  
...  
Keyword(s):  
High Throughput ◽  
Particle Density ◽  
Rotational Dynamics ◽  
Rotational Inertia ◽  
Fluid Viscosity ◽  
Rigid Particle ◽  
Particle Volume ◽  
Inertial Sensing ◽  
Hydrodynamic Coupling ◽  
Atomic Precision

AbstractRotational dynamics often challenge physical intuition while enabling unique realizations, from the rotor of a gyroscope that maintains its orientation regardless of the outer gimbals, to a tennis racket that rotates around its handle when tossed face-up in the air. In the context of inertial sensing, which can measure mass with atomic precision, rotational dynamics are normally considered a complication hindering measurement interpretation. Here, we exploit the rotational dynamics of a microfluidic device to develop a modality in inertial sensing. Combining theory with experiments, we show that this modality measures the volume of a rigid particle while normally being insensitive to its density. Paradoxically, particle density only emerges when fluid viscosity becomes dominant over inertia. We explain this paradox via a viscosity-driven, hydrodynamic coupling between the fluid and the particle that activates the rotational inertia of the particle, converting it into a ‘viscous flywheel’. This modality now enables the simultaneous measurement of particle volume and mass in fluid, using a single, high-throughput measurement.

The Investigation of Proppant Particle-Fluid Flow in the Vertical Fracture with a Contracted Aperture

SPE Journal ◽  
2021 ◽  
pp. 1-18
Author(s):  
Hai Qu ◽  
Rui Wang ◽  
Xiang Ao ◽  
Ling Xue ◽  
Zhonghua Liu ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Volume Fraction ◽  
Particle Density ◽  
Particle Volume Fraction ◽  
Experimental Results ◽  
Fluid Viscosity ◽  
Flow Conditions ◽  
Particle Volume ◽  
Proppant Transport ◽  
Bed Height

Summary Proppant placement plays a crucial role in maintaining the conductivity of fractures after a hydraulic fracturing treatment. The process involves the transport of particles by fluid flow in complex fractures. Many studies have focused on proppant transport and distribution in the fracture with a constant aperture, but relatively few studies have investigated the proppant-fluid flow in a vertical fracture with a contracted aperture. In this work, we examine experimentally proppant transport in a fracture with a contracted aperture. The objective is to evaluate the distribution of particle beds in the contracted fracture at different flow conditions. In this paper, particle-fluid flow in the contracted fracture is studied experimentally by a laboratory size slot. A planar slot with a constant width is used to benchmark the experimental results, and a published correlation validates the bed equilibrium heights in the planar slot. Six types of particles are chosen to simulate the effects of particle density and size. The proppant distribution is evaluated by the bed height when the bed reaches the equilibrium states. The effects of fluid velocity, fluid viscosity, particle density, particle size, and particle volume fraction on particle distribution are investigated. The results confirm that the proppant particle-fluid flow in the contracted slot is more complicated than that in the planar slot. The phenomena of particle vortices and resuspension were observed at the contraction of the cross-section. The shape on the top of the bed is like a descending stair in which the height gradually decreases in the length direction. The bed height in the contracted slot is lower and more irregular than that in the planar slot at the same flow conditions. Smaller sands injected at a high flow rate and fluid viscosity can form a lower bed. The trend would be reversed by using denser particles and high particle volume fraction. A reliable model expressed by four dimensionless numbers is developed by the linear regression method for predicting the bed equilibrium height. The model and experimental results provide directions to quantitatively evaluate the particle transport and distribution in a fracture with a contracted aperture.

Gastric emptying of nondigestible solids in dogs: a hydrodynamic correlation

1990 ◽  
Vol 258 (1) ◽  
pp. G65-G72 ◽  
Author(s):  
P. J. Sirois ◽  
G. L. Amidon ◽  
J. H. Meyer ◽  
J. Doty ◽  
J. B. Dressman
Keyword(s):  
Particle Size ◽  
Gastric Emptying ◽  
Gravitational Constant ◽  
Particle Density ◽  
Particle Diameter ◽  
High Viscosity ◽  
Fluid Viscosity ◽  
Fluid Flow Rate ◽  
Hydrodynamic Correlation ◽  
Viscosity Polymer

The influence of particle size, particle density, fluid viscosity, and fluid flow rate on the gastric emptying of nondigestible solids was investigated in five dogs with chronically placed fistulas. Six hundred and fifty particles of 13 different size and density combinations were administered simultaneously with 500 ml of either normal saline or low-, medium-, or high-viscosity polymer solutions. The canine stomach was found to discriminate between these solids on the basis of size and density at all levels of viscosity above saline. The observed patterns of emptying are consistent with the hypothesis that gastric emptying of nondigestible solids is governed in part by hydrodynamics and correlate well with the gastric-emptying coefficient (GEC), a dimensionless grouping of variables that takes the form GEC = (Dpy/Dp) [g(rho f - rho p)Dp2]/[eta (nu)] where [g(rho f - rho p)] is particle buoyancy consisting of fluid (rho f) and particle (rho p) densities and g, the gravitational constant; (Dp) is the particle diameter, (Dpy) the estimated pyloric diameter, eta the fluid viscosity, and (nu) the average linear velocity of fluid exiting the stomach.

scholarly journals Scale-up of the jetcutter technology

2003 ◽  
Vol 57 (12) ◽  
pp. 636-640 ◽  
Author(s):  
Ulf Pruesse ◽  
Ulrich Jahnz ◽  
Peter Wittlich ◽  
Klaus-Dieter Vorlop
Keyword(s):  
High Throughput ◽  
Large Scale ◽  
Size Range ◽  
Scale Up ◽  
Viscous Fluids ◽  
Fluid Viscosity ◽  
Efficient Technology ◽  
Particle Size Range ◽  
Hydrogel Beads ◽  
Improved Stability

The JetCutter is a new, simple and efficient technology for the high throughput encapsulation of various materials inside spherical beads. Monodisperse beads in the particle size range from approximately 0.2 mm up to several millimeters can be prepared at high throughput rates with the JetCutter. The generation of beads is not limited by the fluid viscosity. Thus, also highly viscous fluids even with high loadings of solids, can be processed, which leads to an improved stability of the resulting beads. The JetCutter technology is available in different scales and corresponding throughputs ranging from lab-scale devices (liters per day) up to large scale installations for industrial production purposes (tons per day). The application of the JetCutter for industrial purposes has been well established by geniaLab?, which currently produces more than 40 tons/year of small hydrogel beads.

scholarly journals Preaggregation reactions of platelets

Blood ◽  
1981 ◽  
Vol 58 (3) ◽  
pp. 477-490 ◽  
Author(s):  
AR Gear
Keyword(s):  
Particle Density ◽  
Morphological Changes ◽  
Adenosine Diphosphate ◽  
Temperature Cycle ◽  
Volume Changes ◽  
Platelet Volume ◽  
Particle Volume ◽  
Before And After ◽  
Subsequent Exposure ◽  
Platelet Shape

Abstract Whether platelet volume increases during the morphological changes preceding aggregation has been investigated. Previous research is controversial; resistive-counting techniques reveal an increase, centrifugal methods do not. Platelets were sized with a computerized, resistive-particle counter before and after incubation with adenosine diphosphate (ADP). Resistive volume increased by 14% (p less than 0.001) in the absence of EDTA, and only 7% in its presence (ADP, 10 micro M). EDTA inhibited platelet volume changes, whether these were shrinking induced by warming or swelling by ADP. Handling of platelets, such as during centrifugation, also caused particle swelling. Particle density decreased after ADP exposure, without release of serotonin, suggesting uptake of water. Platelet shape was experimentally manipulated to test the hypothesis that resistive volume changes stem from artifacts of particle shape. Scanning electron microscopy confirmed that colchicine, chlorpromazine, and a temperature cycle of 0 degrees to 37 degrees all caused extensive alteration from the disc shape. Subsequent exposure to ADP increased resistive volume, and in the case of chlorpromazine, no long pseudopodia were extruded. It is concluded that preaggregation reactions of platelets can be associated with an increase in particle volume, and that earlier research based on centrifugation and the presence of ETA failed to reveal the increase because of inhibitory and apparent swelling effects.

Chip Removal by a Hydraulic Jet

1964 ◽  
Vol 4 (01) ◽  
pp. 21-25 ◽  
Author(s):  
J.B. Cheatham ◽  
J.G. Yarbrough
Keyword(s):  
Flow Rate ◽  
Particle Density ◽  
Experimental Studies ◽  
Fluid Viscosity ◽  
Drill Bit ◽  
Hole Size ◽  
Rock Fracturing ◽  
Fracturing Process ◽  
Jet Velocity ◽  
Chip Removal

Abstract Although adequate removal of cuttings from beneath a drill bit is important for efficient drilling operations, very little basic data are available relative to the fundamentals of chip removal by hydraulic jets. A discussion is presented in this paper of an experimental investigation of the jetting action of hydraulic jets in removing loose particles from the bottom of a cylindrical hole. Conditions for which the jet is no longer capable of removing chips from the bottom of the hole are determined. This situation represents equilibrium between the chip removal force and chip holddown forces such as gravity and pressure. In most of the tests loose particles were jetted with water or a water-glycerine mixture to determine the dependence of chip removal on hole size, jet size, height of jet off bottom of hole, flow rate, particle density and fluid viscosity. A test with a pressurized mud system indicated that relatively low pressures can completely overcome the removal action of a hydraulic jet. Although the system studied herein is not directly applicable to a rotary drill bit, the work with such simplified systems can provide a better understanding of the chip removal action of jets, and with logical extensions it may provide a reasonable basis for the best use of fluid jets in drilling. Introduction The primary deterrent to maximum drilling rates is the inability of the drilling system to remove rock cuttings efficiently enough to prevent interference with the drilling action. The objective of chip removal studies is to permit predicting and controlling removal forces under downhole drilling conditions. Conditions at the bottom of a hole during rotary drilling are exceedingly complex and are not likely to be described in a quantitative way by investigations in terms of the total drilling action until a better understanding is developed of the simplified components of the problem. The present study is concerned with the elementary condition of removal of chips by a single central jet. Even this relatively simple model provides mathematical difficulties because of the turbulent nature of the flow from the jet and because of the shape of the bottom of the hole beneath the jet. Theoretical and experimental studies have been made of turbulent jets impinging normally on an infinite body and deductions based on analytical solutions to simplified problems can give some insight into the problem of cutting removal by a jet. However, because of the present lack of understanding of the behavior of the interaction between the fluid jet and the chips being removed, an experimental approach was chosen for the present study. Methods have been developed for maximizing hydraulic horsepower, impact force and jet velocity; but whether maximizing these parameters maximizes chip removal with present drilling bits has not been demonstrated. Simplifying the problem of chip removal may make it possible to develop some understanding of the manner in which the jet velocity is dissipated. Better understanding of a simple case should materially assist in extending analysis to more complicated cases. Thus, we are not concerned in the present study with the rock fracturing process itself but only with the removal of the debris from the bottom of the hole. A problem which is quite similar to the chip removal problem is the suspension of solids in stirred vessels. This problem has been studied by the chemical industry and correlations have been obtained by dimensional analysis which permit the design of mixing vats. An approach similar to that used in the mixing vat problem is used in the analysis of the jetting data in the present paper. EXPERIMENTAL PROCEDURE The test equipment arrangement shown schematically in Fig. 1 allows the jetting action to remove particles until an equilibrium height is attained for each combination of hole size, jet size and flow rate.*** Equilibrium conditions require that the removal force is unable to remove additional particles. This balance between holddown and removal forces implies a relationship between the two forces which is constant for the particular system. When the holddown forces are constant, SPEJ P. 21ˆ

The motion of Brownian particles and sediment on an inclined plate

1997 ◽  
Vol 337 ◽  
pp. 25-47 ◽  
Author(s):  
A. A. DAHLKILD
Keyword(s):  
Volume Fraction ◽  
Particle Density ◽  
Particle Volume Fraction ◽  
Present Theory ◽  
Brownian Diffusion ◽  
Inclined Plate ◽  
Particle Volume ◽  
Hindered Settling ◽  
Brownian Particles ◽  
And Migration

The gravitational settling of a homogeneous suspension of Brownian particles on an inclined plate is considered. The hindered settling towards the wall and the viscous, buoyancy-driven bulk motion of the sediment are considered assuming steady conditions and accounting for the effects of Brownian diffusion, shear-induced diffusion and migration of particles due to a gradient in shear stress. Generally, the results show the development of a sediment boundary layer where the settling towards the wall is balanced by Brownian diffusion at the beginning of the plate and by shear-induced diffusion further downstream. Compared to previous results in the literature, the present theory allows steady-state solutions for extended values of the plate inclination and particle volume fraction above the sediment; upon reconsidering the case with non-Brownian particles, a new similarity solution, with a stable shock in particle density, is developed.

scholarly journals Epoxidized graphene grid for high-throughput high-resolution cryoEM structural analysis

2021 ◽  
Author(s):  
Junso Fujita ◽  
Fumiaki Makino ◽  
Haruyasu Asahara ◽  
Maiko Moriguchi ◽  
Shota Kumano ◽  
...  
Keyword(s):  
Structural Analysis ◽  
High Resolution ◽  
Data Collection ◽  
High Throughput ◽  
Particle Density ◽  
Orientation Distribution ◽  
Biological Macromolecules ◽  
Density Maps ◽  
V1 Atpase ◽  
Density Map

Many specimens suffer from low particle density and/or preferred orientation in cryoEM specimen grid preparation, making data collection and structure determination time consuming. We developed an epoxidized graphene grid (EG-grid) that effectively immobilizes protein particles by applying an oxidation reaction using photoactivated ClO2· and further chemical modification. The particle density and orientation distribution are both dramatically improved, having enabled us to reconstruct the density map of GroEL and glyceraldehyde 3-phosphate dehydrogenase (GAPDH), at 1.99 and 2.16 Å resolution from only 504 and 241 micrographs, respectively. A low concentration sample solution of 0.1 mg ml–1 was sufficient to reconstruct a 3.10 Å resolution density map of SARS-CoV-2 spike protein from 1,163 micrographs. The density maps of V1-ATPase, β-galactosidase, and apoferritin were also reconstructed at 3.03, 1.81, and 1.29 Å resolution, respectively. These results indicate that the EG-grid will be a powerful tool for high-throughput cryoEM data collection to accelerate high-resolution structural analysis of biological macromolecules.

Estimation of engine rotational dynamics using a closed-loop estimator with stroke identification for engine management systems

2005 ◽  
Vol 219 (12) ◽  
pp. 1391-1405 ◽  
Author(s):  
B-C Chen ◽  
Y-Y Wu ◽  
F-C Hsieh
Keyword(s):  
Engine Speed ◽  
Closed Loop ◽  
Fuel Injection ◽  
Rotational Dynamics ◽  
Engine Management System ◽  
Rotational Inertia ◽  
Engine Model ◽  
Crank Angle ◽  
The Stability ◽  
Engine Management

In order to study the effect of the crank sensor noise on the engine management system (EMS), an algorithm using a closed-loop estimator with stroke identification is proposed to estimate the engine rotational dynamics. Estimated crank angle and engine speed are used for fuel injection and ignition control systems. The closed-loop estimator design is based on a linear model by assuming that the engine rotational inertia is constant. Since the effective inertia actually varies with different crank angles, the stability of the proposed algorithm is assessed using the Lyapunov stability theorem. Performances of the proposed and traditional algorithms are evaluated using a non-linear engine model with a four-plus-one-tooth crankshaft wheel in Matlab/Simulink. The estimated crank angle and engine speed of the traditional algorithm can be significantly affected by large sensor noises resulting from the poorly grounded ignition coil. It was found that the proposed algorithm can mitigate the noise impact and thus maintain the desired engine control performance.

scholarly journals Hydrodynamics control shear-induced pattern formation in attractive suspensions

2019 ◽  
Vol 116 (25) ◽  
pp. 12193-12198 ◽  
Author(s):  
Zsigmond Varga ◽  
Vincent Grenard ◽  
Stefano Pecorario ◽  
Nicolas Taberlet ◽  
Vincent Dolique ◽  
...  
Keyword(s):  
Shear Flow ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Quantitative Agreement ◽  
Stability Diagram ◽  
Periodic Pattern ◽  
Simple Shear Flow ◽  
Parallel Plates ◽  
Particle Volume ◽  
Hydrodynamic Coupling

Dilute suspensions of repulsive particles exhibit a Newtonian response to flow that can be accurately predicted by the particle volume fraction and the viscosity of the suspending fluid. However, such a description fails when the particles are weakly attractive. In a simple shear flow, suspensions of attractive particles exhibit complex, anisotropic microstructures and flow instabilities that are poorly understood and plague industrial processes. One such phenomenon, the formation of log-rolling flocs, which is ubiquitously observed in suspensions of attractive particles that are sheared while confined between parallel plates, is an exemplar of this phenomenology. Combining experiments and discrete element simulations, we demonstrate that this shear-induced structuring is driven by hydrodynamic coupling between the flocs and the confining boundaries. Clusters of particles trigger the formation of viscous eddies that are spaced periodically and whose centers act as stable regions where particles aggregate to form flocs spanning the vorticity direction. Simulation results for the wavelength of the periodic pattern of stripes formed by the logs and for the log diameter are in quantitative agreement with experimental observations on both colloidal and noncolloidal suspensions. Numerical and experimental results are successfully combined by means of rescaling in terms of a Mason number that describes the strength of the shear flow relative to the rupture force between contacting particles in the flocs. The introduction of this dimensionless group leads to a universal stability diagram for the log-rolling structures and allows for application of shear-induced structuring as a tool for assembling and patterning suspensions of attractive particles.

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