Fluid Transport Characteristics Research Articles

Effect of nano zinc oxide and silica on mechanical, fluid transport and radiation attenuation properties of steel furnace slag heavyweight concrete

Due to the growing nuclear energy sector worldwide, it has been a global interest among researchers to improve the harmful radiation isolation properties of concrete for preserving both environment and human safety in nuclear power plant applications. While nano zinc oxide, nano-silica and steel furnace slag have high molar mass and favorable physical properties to improve high energy radiation attenuation properties of the concrete, scarce body of literature on the subject matter was reported. Hence, the study was aimed to investigate the suitability of the addition of nanomaterials such as nano-silica and nano zinc oxide for improving the mechanical, fluid transport and gamma-ray attenuation properties of heavyweight concrete (HWC) containing aggregate of steel furnace slag (ASFS). A new contribution of this study was the use of nano zinc oxide and nano-silica in concrete binder formulation to enhance the gamma ray shielding ability of concrete. A method was established for the optimization of the nano zinc oxide content used in combination with a constant amount of nano-silica to improve the various performance of heavy weight concrete. An investigation program was implemented with six concrete mixes which were prepared by utilizing ASFS with the addition of a superplasticizer, 3% of nano-silica in combination with (0.5–2.5%) of nano zinc oxide as an additive to produce high strength heavy weight concrete. The mechanical properties, fluid transport characteristics and γ-ray shielding performance were evaluated for hardened concrete samples. The inclusion of 1.5% nano zinc and 3% of nano-silica enhances the gamma-ray shielding and compressive strength by 16.3 and 6.6%, respectively, at 28 days as compared to the control mix (without nanomaterials). Besides, all the mechanical and fluid transport properties of the concrete were improved correspondingly. In conclusion, the combined use of nano-silica and nano zinc oxide is suitable to enhance mechanical strength, fluid transport and high energy radiation attenuation performance of steel furnace-slag heavyweight concrete (SSHWC).

Microfluidic Behavior of Alumina Nanotube-Based Pathways within Hydrophobic CNT Barriers.

The use of porous micro-and nanostructured materials within microfluidic devices results in unique fluid transport characteristics. In this paper, we investigate the microfluidic behavior of hybrid alumina nanotube-based pathways within the hydrophobic carbon nanotube (CNT) barriers. These hybrid systems provide unique benefits for potential liquid transport control in porous structures with real-time sensing of fluids. In particular, we examine how the alignment of the alumina nanostructures with high internal porosity enables increased capillary action and sensitivity of detection. Based on the Lucas and Washburn model (LW) and the modified LW models, the microfluidic behavior of these systems is detailed. The time exponent prediction from the models for capillary transport in porous media is determined to be ≤0.5. The experimental results demonstrate that the average capillary rise in the nanostructured media driven by a capillary force follows t0.7. The hydrophilic/electrically insulating and hydrophobic/electrically conductive patterned structures of the device are used for electronic measurements within the microfluidic channels. The device structure enables the detection of fluid samples of very low analyte concentrations (1 μM) that can be achieved due to the very high surface area of the hybrid structure combined with the electrical conductivity of the CNT support structure.

Entropy generation of tangent hyperbolic nanofluid flow over a circular cylinder in the presence of nonlinear Boussinesq approximation: a non-similar solution

The analysis of entropy generation has received notable attention in the study of nanofluids because the prime objective of nanofluids is to admit high heat fluxes. The entropy production can be utilized to generate the entropy in any irreversible heat transfer process which is important in thermal machines. This work presents to explore the fluid transport characteristics and entropy generation of a tangent hyperbolic nanofluid over a horizontal circular cylinder with the influence of nonlinear Boussinesq approximation. The dimensionless nonlinear partial differential equations have been solved by using an implicit finite difference Keller box scheme. The impacts of active parameters on the flow field like Weissenberg number, power-law index, magnetic field, mixed convection, Brownian motion, thermal convention, thermophoresis and radiation are illustrated with graphs and tables. The current results exposed that the nanofluid velocity enhances for enhancing the mixed convection parameter. Isotherms thickness is escalated with increasing values of radiation parameter. Total entropy generation rises for higher values of dimensionless temperature ratio parameter.

Predicting transport characteristics of hyperuniform porous media via rigorous microstructure-property relations

This paper is concerned with the estimation of the effective transport characteristics of fluid-saturated porous media via rigorous microstructure-property relations. We are particularly interested in predicting the formation factor F, mean survival time τ, principal NMR (diffusion) relaxation time T1, principal viscous relaxation time Θ1, and fluid permeability k. To do so, we employ rigorous methods to estimate the fluid permeability and these other transport properties of “hyperuniform” and nonhyperuniform models of porous media from microstructural information. Disordered hyperuniform materials are exotic amorphous states of matter that have attracted great attention in the physical, mathematical and biological science but little is known about their fluid transport characteristics. In carrying out this investigation, we not only draw from ideas and results of the emerging field of hyperuniformity, but from homogenization theory, statistical geometry, differential equations (spectrum of Laplace and Stokes operators), and the covering and quantizer problems of discrete geometry. Among other results, we derive a Fourier representation of a classic rigorous upper bound on the fluid permeability that depends on the spectral density to infer how the permeabilities of hyperuniform porous media perform relative to those of nonhyperuniform ones. We find that the velocity fields in nonhyperuniform porous media are generally much more localized over the pore space compared to those in their hyperuniform counterparts, which has implications for their permeabilities. Rigorous bounds on transport properties suggest a new approximate formula for the fluid permeability that provides reasonably accurate permeability predictions of a certain class of hyperuniform and nonhyperuniform porous media. These comparative studies shed new light on the microstructural characteristics that determine the transport properties of general porous media. Our findings also have implications for the design of porous materials with desirable transport properties.

A numerical study of the ferromagnetic flow of Carreau nanofluid over a wedge, plate and stagnation point with a magnetic dipole

Present communication mainly addresses the fluid transport characteristics of ferromagnetic Carreau nanofluid over a porous wedge, plate, and stagnation point with magnetic dipole effect for shear thinning/shear thickening cases. Suitable self-similarity variables are employed to convert the fluid transport equations into ordinary differential equations which are solved with the use of the Runge-Kutta-Fehlberg (RKF) approach. To check the accuracy of the present model, numerical results for various thermophoretic values for the cases of shear thinning/shear thickening, have been compared with the results obtained by using bvp4c (MATLAB) which divulges good agreement. Influence of active parameters like ferromagnetic-hydrodynamic interaction, thermophoretic, dimensionless distance, Brownian diffusion, suction/injection, Weissenberg number are graphically presented. Computed results manifest that shear thinning and shear thickening fluids express the opposite nature in fluid velocity and temperature for higher values of Weissenberg number. Among the wedge, plate and stagnation point of the plate, the magnitude of heat transfer over the plate is significant for increasing Ferromagnetic-hydrodynamic interaction parameter. Furthermore, it is noticed that higher values of suction/injection parameter decline the fluid temperature over a plate, wedge and stagnation point of a flat plate.

Inertia-driven flow symmetry breaking by oscillating plates

While cilia are generally found in viscosity-dominated regimes, those of a comb jelly, the longest motile cilia in nature, are used for propulsion and feeding in inertia-dominated flows. Motivated by the effective fluid transport of cilia at relatively high Reynolds number, the characteristics of vortex formation and fluid transport are investigated numerically for a simple two-dimensional model of rigid plates in Re = O(10 − 102). The small plates oscillate symmetrically on both walls of a channel. Under some conditions, the vortical structures generated by the plates become asymmetric notably with respect to the channel midline. In relatively narrow channels, the interaction of counter-rotating vortices shed directly from the plates near the midline causes symmetry breaking, and thus the mixing of fluid particles across the midline is enhanced greatly. Meanwhile, in relatively wide channels, the diffused weak vortices that persist after previous strokes become asymmetric first. When the number of oscillating plates on each wall increases, the vortex generated by a plate is confined between two plates, and it is annihilated by the counter-rotating vortex generated by a neighbor plate during stroke reversal, thereby keeping them from propagating toward the midline. This collective motion of multiple plates hinders the vortices from undergoing symmetry breaking even at the relatively high Reynolds number of Re = 200, and mixing is suppressed accordingly.

History Matching and Forecast of Shale Gas Production Considering Hydraulic Fracture Closure

Most shale gas reservoirs have extremely low permeability. Predicting their fluid transport characteristics is extremely difficult due to complex flow mechanisms between hydraulic fractures and the adjacent rock matrix. Recently, studies adopting the dynamic modeling approach have been proposed to investigate the shape of the flow regime between induced and natural fractures. In this study, a production history matching was performed on a shale gas reservoir in Canada’s Horn River basin. Hypocenters and densities of the microseismic signals were used to identify the hydraulic fracture distributions and the stimulated reservoir volume. In addition, the fracture width decreased because of fluid pressure reduction during production, which was integrated with the dynamic permeability change of the hydraulic fractures. We also incorporated the geometric change of hydraulic fractures to the 3D reservoir simulation model and established a new shale gas modeling procedure. Results demonstrate that the accuracy of the predictions for shale gas flow improved. We believe that this technique will enrich the community’s understanding of fluid flows in shale gas reservoirs.

Influence of the Main Border Faults on the 3D Hydraulic Field of the Central Upper Rhine Graben

The Upper Rhine Graben (URG) is an active rift with a high geothermal potential. Despite being a well-studied area, the three-dimensional interaction of the main controlling factors of the thermal and hydraulic regime is still not fully understood. Therefore, we have used a data-based 3D structural model of the lithological configuration of the central URG for some conceptual numerical experiments of 3D coupled simulations of fluid and heat transport. To assess the influence of the main faults bordering the graben on the hydraulic and the deep thermal field, we carried out a sensitivity analysis on fault width and permeability. Depending on the assigned width and permeability of the main border faults, fluid velocity and temperatures are affected only in the direct proximity of the respective border faults. Hence, the hydraulic characteristics of these major faults do not significantly influence the graben-wide groundwater flow patterns. Instead, the different scenarios tested provide a consistent image of the main characteristics of fluid and heat transport as they have in common: (1) a topography-driven basin-wide fluid flow perpendicular to the rift axis from the graben shoulders to the rift center, (2) a N/NE-directed flow parallel to the rift axis in the center of the rift and, (3) a pronounced upflow of hot fluids along the rift central axis, where the streams from both sides of the rift merge. This upflow axis is predicted to occur predominantly in the center of the URG (northern and southern model area) and shifted towards the eastern boundary fault (central model area).

Evolution of permeability in a single granite fracture at high temperature

Thermal energy recovered from Hot Dry Rock (HDR) or Engineered Geothermal Systems (EGS) is clean and renewable and may fulfill current energy demands. The long term flow characteristic of fractures is a key issue related to both the rate of geothermal production and the service life of the geothermal reservoir. We explore the long term fluid transport characteristics of a long (50 mm wide and 300 mm long) artificial fracture in granite at temperatures to 200 °C. Permeability is measured under steady flow conditions in three stages: (1) stepped increments of temperature from 25 °C to 200 °C; (2) constant temperature of 200 °C applied for 27 h; (3) gradually decreased temperature from 200 °C to 25 °C. The evolution of hydraulic aperture and permeability of the fracture is evaluated over these three regimes. Hydraulic aperture and permeability decrease with the increase in temperature. Uniform high temperatures result in a continued but gradual reduction in both hydraulic aperture and permeability. The reduction in hydraulic aperture and permeability of the fracture is permanent with marginal recovery as the temperature is reset to the original 25 °C. Permeability and heat transfer efficiency increase during heating (stage 1), but decrease during high temperature production and then cooling (stages 2 and 3).

Influence of rotating magnetic field on Maxwell saturated ferrofluid flow over a heated stretching sheet with heat generation/absorption

This article is focused on Maxwell ferromagnetic fluid and heat transport characteristics under the impact of magnetic field generated due to dipole field. The viscous dissipation and heat generation/absorption are also taken into account. Flow here is instigated by linearly stretchable surface, which is assumed to be permeable. Also description of magneto-thermo-mechanical (ferrohydrodynamic) interaction elaborates the fluid motion as compared to hydrodynamic case. Problem is modeled using continuity, momentum and heat transport equation. To implement the numerical procedure, firstly we transform the partial differential equations (PDEs) into ordinary differential equations (ODEs) by applying similarity approach, secondly resulting boundary value problem (BVP) is transformed into an initial value problem (IVP). Then resulting set of non-linear differentials equations is solved computationally with the aid of Runge–Kutta scheme with shooting algorithm using MATLAB. The flow situation is carried out by considering the influence of pertinent parameters namely ferro-hydrodynamic interaction parameter, Maxwell parameter, suction/injection and viscous dissipation on flow velocity field, temperature field, friction factor and heat transfer rate are deliberated via graphs. The present numerical values are associated with those available previously in the open literature for Newtonian fluid case (γ 1 = 0) to check the validity of the solution. It is inferred that interaction of magneto-thermo-mechanical is to slow down the fluid motion. We also witnessed that by considering the Maxwell and ferrohydrodynamic parameter there is decrement in velocity field whereas opposite behavior is noted for temperature field.

Chaotic Manifold Analysis of Four-Screw Extruders Based on Lagrangian Coherent Structures.

The four-screw extruder (FSE) is a novel equipment for polymer processing. In this paper, from a new viewpoint of Lagrangian coherent structures (LCS), two-dimensional fluid transport and chaotic mixing characteristics within three kinds of novel industrial FSEs are explored based on LCS to better understand the flow and mixing natures in the FSEs. Firstly, based on the finite-time invariant manifold theory, the finite-time Lyapunov exponent (FTLE) and LCS of FSEs are calculated by considering the different initial time. Hyperbolic LCSs from the FTLE maps are adopted to identify chaotic mixing manifolds in FSEs. Moreover, particle tracking and Poincaré sections are used to illustrate the different fluid motions in the above three isolated regions. Finally, the effects of relative rotating directions and layout of four screws on the chaotic manifolds in FESs are discussed in order to enhance local mixing performance. Furthermore, quantitative mixing measures, such as the segregation scale, logarithmic of stretching, and mean-time mixing efficiency are employed to compare the mixing efficiencies in three kinds of FSEs. The results show that the relative rotating directions and positions of four screws can change the chaotic manifolds and increase mixing performance in local poor mixing regions. FTLE and LCS analysis are helpful to better understand the chaotic mixing nature in the novel screw extruders.

Experimental research on remaining oil distribution and recovery performance after immiscible and miscible CO<SUB align="right">2-WAG injection by direct visualisation

More than half of oil remains in the reservoir pores after water flooding. A microscopic visualised physical model under high temperature and pressure was created to simulate a reservoir pore network. It is an efficient way to study the formation and distribution of microscopic remaining oil which can enhance oil recovery. Displacement mechanisms were researched for CO2/water alternative flooding (CO2-WAG). The remaining oil morphology and migration characteristics were directly observed and analysed. The distribution of the remaining oil of models in different flooding stages was quantitatively obtained by grey images processing technology. Comparing the distribution of different occurrences of microscopic remaining oil, the multiphase fluid transport characteristics in the experimental porous media is described. Experimental results show that the recovery efficiency under the CO2-oil miscible state can be enhanced 5.75% more than the immiscible state. There exist four types of remaining oil after CO2-WAG with different effects, namely: 1) clusters; 2) columnar; 3) membrane; 4) blind-end remaining oil. Miscible CO2-WAG could efficiently improve oil recovery of cluster, column, and membrane types of remaining oil. Immiscible CO2-WAG only caused an obvious recovery improvement for the cluster type of remaining oil. In order for CO2-WAG flooding to be used to improve oil recovery most efficiently, the occurrence state and distributions of remaining oil should first be considered. [Received: June 23, 2015; Accepted: March 1, 2016]

Criteria for Freeze-Thaw Resistant Concrete Mixtures

Abstract Concrete, especially for improved durability, is typically specified with prescriptive provisions. More recently there has been increasing interest in evolving towards performance-based specifications, both within state highway agencies and industry (FHWA, 2014, “Guide to Developing Performance-Related Specifications, FHWA-RD-98-155, FHWA-RD-98-156, FHWA-RD-98-171, Vol. III, Appendix C,” http://www.fhwa.dot.gov/publications/research/infrastructure/pavements/pccp/pavespec/, last accessed July 28, 2014; ACI Committee 329, Report on Performance-Based Requirements for Concrete, American Concrete Institute, Farmington Hills, 2010; The P2P Initiative, 2014, “National Ready Mixed Concrete Association, Silver Spring,” http://www.nrmca.org/p2p/, last accessed July 28, 2014). One of the challenges in successfully implementing performance-based specifications is the existence and use of reliable test methods and specification criteria that can measure the potential durability of concrete mixtures and provide the expected service life. A state pooled fund research project (TPF-5 (179), 2014, “Evaluation of Test Methods for Permeability (Transport) and Development of Performance Guidelines for Durability,” http://www.pooledfund.org/Details/Study/406, last accessed July 28, 2014) was developed with an objective to propose performance criteria for concrete that will be resistant to penetration of chlorides, cycles of freezing and thawing, and sulfate attack. This paper summarized results pertaining to freeze-thaw resistance. Concrete freeze-thaw (F-T) performance was evaluated by ASTM C666/C666M-15 (AASHTO T161-08 (Standard Method of Test for Resistance of Concrete to Rapid Freezing and Thawing, Standard Specifications for Transportation Materials and Methods of Sampling and Testing, Part 2A: Tests, AASHTO, Washington DC, 2013)) and deicer salt scaling resistance was evaluated by ASTM C672/C672M-12. It was examined whether F-T performance of concrete correlated with results of rapid index tests for fluid transport characteristics of concrete. These tests included the rapid chloride permeability, absorption, and initial and secondary sorptivity. The impact of degree of saturation on the F-T resistance of concrete was also explored. Criteria for F-T resistant concrete mixtures depending on type of exposure were suggested.

Numerical modeling of liquid–gas two-phase flow and heat transfer in reconstructed porous media at pore scale

The complicated multiphase flow in porous media is one important issue in the field of energy utilization. This work performed the pore-scale lattice Boltzmann modeling and simulation of liquid–gas two-phase fluid transport phenomena within porous domain. The three-dimensional porous structure was numerically reconstructed with high-resolution CT scan images. The flow and thermal parameters in porous spaces were obtained under the conditions of different contact angles. The liquid water in the porous domain with hydrophilic solid surface reaches the equilibrium state more quickly compared to that in hydrophobic one. The numerical approach established in this paper can provide detailed information of the multiphase fluid transport characteristics in complex porous media.

Femtosecond-laser-structured nitrocellulose membranes for multi-parameter Point-of-Care tests

Cheap and disposable Point-of-Care diagnostic devices are of great interest to combat the rising cost of healthcare in industrial nations but also for a widespread use in the developing world. Paper based microfluidic devices as well as well-established lateral flow tests (LFTs) are both well suited for this role. However, they share various disadvantages including restricted reproducibility for quantitative readouts and are in most cases limited to a single parameter per test. In order to address these drawbacks we present a novel laser fabrication method for multi-parametric lateral flow tests based on nitrocellulose membranes. Using a femtosecond laser the membrane can be structured into barriers and channels which separate and guide the test liquid. By varying the laser parameters the presented method allows the rapid area-selective ablation of the entire membrane-thickness to the polyester backing thus creating a barrier for the fluid transport as well as a much finer, but slower, removal of the membrane material which leaves the membranes pore structure and fluid transport characteristics intact. With barrier and channel widths of 100μm and 300–600μm this process enables the integration of complex multi-parametric detection fluidic networks in the footprint of commercially available LFTs.

Liquid transmission characteristics of padding bandages under pressure.

Padding is an essential component in a multilayer compression bandaging system, used inside the compression bandage through which substantial amount of pressure is exerted on the limb of patient for treatment of venous leg ulcers. As a result, the liquid transmission behavior of padding is also critical in managing body fluids or sweat exuded from the affected limb, reducing the excessive moisture build-up around the wound and thereby ensuring comfort to and hence a better compliance from the patients. This study investigates the in-plane fluid transport characteristics of needle-punched nonwoven padding bandages. It first reviewed the existing studies related to the problems, and discussed their limits and possible improvements in dealing with complex fluid transport issues in textile porous media. The measurement of fluid transport under different pressure levels was then done using a newly designed apparatus capable of simultaneously tracing the liquid in-plane spreading along different directions, and obtaining several transport characteristics of a testing sample, e.g. the liquid flow anisotropy, the rate of movement, the area of wet surface with time, etc. Also the effects of several important factors, such as the levels of pressure applied, the specimen bulk density, and needling density of the padding products, have been experimentally investigated. In addition, based on an extended Lucas-Washburn theory, we calculated the liquid flow distance, both instantaneous speed and a more useful time-averaged speed v(av) at any given direction, and also defined a flow anisotropy index I(A) as a convenient parameter to represent the material flow anisotropy. The applications of v(av) and I(A) to actual samples have demonstrated the usefulness of these parameters in characterizing the flow nature and behavior of the materials.

Characteristics and sedimentary processes of lamina-controlled sand-particle imbricate structure in deposits on Lingshan Island, Qingdao, China

Imbricate structure is a common sedimentary structure and is well developed in sandy sediments. Here, we report a lamina-controlled fine-sand-particle imbricate structure in a set of very fine grained sedimentary rocks (fine sandstone, siltstone, and mudstone) at the Dockyard and Qianceng Cliff areas of Lingshan Island, Qingdao, Shandong, China. Sets of up to 300 laminae are found in stratigraphic profiles in these areas. The laminae are generally less than 1 mm thick, with most being 0.3–0.4 mm thick and the thinnest being <0.1 mm. The dip angle of the imbricate structure varies widely, between 0° and 90°, with an average dip angle of about 40°–50°, which is higher than that of imbricate riverbed gravels (about 34°). The dip angle is a function of the shape and sorting of the particles, as well as the hydrodynamic conditions under which these fine-grained sediments were deposited. Several profiles show well-developed multiscale, soft-sediment deformation structures. Flute casts, load casts, and groove casts are also common. Fragments of carbon remains occur widely and commonly constitute stringers several millimeters thick and up to 10 cm long, together with fine clasts. Vitrain lenticles are also common. Based on the imbricate structure of the Lingshan Island deposits, it is shown that in addition to paleocurrent analysis, the imbricate structure can be used to infer information about fluid properties, transport characteristics, and sedimentary processes of the depositional environment. A near-bottom underflow, either of authigenic origin or derived from cold river water in winter in a delta interdistributary bay or delta-front environment, is inferred to have provided the hydrodynamic setting in which this imbricate structure formed. The imbricate structure, together with other sedimentary structures and features, shows that the sedimentary rocks on Lingshan Island were deposited in an inland, shallow-water environment, such as a delta, and not in a deep-water or submarine continental-slope environment.

How do walking, standing, and resting influence transtibial amputee residual limb fluid volume?

The purpose of this research was to determine how fluid volume changes in the residual limbs of people with transtibial amputation were affected by activity during test sessions with equal durations of resting, standing, and walking. Residual limb extracellular fluid volume was measured using biompedance analysis in 24 participants. Results showed that all subjects lost fluid volume during standing with equal weight-bearing, averaging a loss rate of -0.4%/min and a mean loss over the 25 min test session of 2.6% (standard deviation [SD] 1.1). Sixteen subjects gained limb fluid volume during walking (mean gain of 1.0% [SD 2.5]), and fifteen gained fluid volume during rest (mean gain of 1.0% [SD 2.2]). Walking explained only 39.3% of the total session fluid volume change. There was a strong correlation between walk and rest fluid volume changes (-0.81). Subjects with peripheral arterial disease experienced relatively high fluid volume gains during sitting but minimal changes or losses during sit-to-stand and stand-to-sit transitioning. Healthy female subjects experienced high fluid volume changes during transitioning from sit-to-stand and stand-to-sit. The differences in fluid volume response among subjects suggest that volume accommodation technologies should be matched to the activity-dependent fluid transport characteristics of the individual prosthesis user.

Sequential peritoneal equilibration test: a new method for assessment and modelling of peritoneal transport

In spite of many peritoneal tests proposed, there is still a need for a simple and reliable new approach for deriving detailed information about peritoneal membrane characteristics, especially those related to fluid transport. The sequential peritoneal equilibration test (sPET) that includes PET (glucose 2.27%, 4 h) followed by miniPET (glucose 3.86%, 1 h) was performed in 27 stable continuous ambulatory peritoneal dialysis patients. Ultrafiltration volumes, glucose absorption, ratio of concentration in dialysis fluid to concentration in plasma (D/P), sodium dip (Dip D/P Sodium), free water fraction (FWF60) and the ultrafiltration passing through small pores at 60 min (UFSP60), were calculated using clinical data. Peritoneal transport parameters were estimated using the three-pore model (3p model) and clinical data. Osmotic conductance for glucose was calculated from the parameters of the model. D/P creatinine correlated with diffusive mass transport parameters for all considered solutes, but not with fluid transport characteristics. Hydraulic permeability (L(p)S) correlated with net ultrafiltration from miniPET, UFSP60, FWF60 and sodium dip. The fraction of ultrasmall pores correlated with FWF60 and sodium dip. The sequential PET described and interpreted mechanisms of ultrafiltration and solute transport. Fluid transport parameters from the 3p model were independent of the PET D/P creatinine, but correlated with fluid transport characteristics from PET and miniPET.

Investigation of delivery system using water model of twin roll strip caster

The fluid transport characteristics and level fluctuations in the pool of twin roll strip casting were studied by physical simulation. The level profile depends on the transport characteristics of the flow in the pool. A 1∶1 water model of a twin roll strip caster was constructed based on the Froude number and Reynolds number similarity criteria to address the relationship between fluid flow and level fluctuations in the pool. The residence time of fluid in the pool and the nip points of the caster were measured to evaluate the uniformity in the caster in different operating conditions, and the level fluctuations and residence time were measured by wave gauge sensors and conductivity sensors respectively. The results show that free surface oscillations increase with the flowrate changing from 8·7 to 14·5 m3 h−1. Suitable outlet extension and outlet angle as well as holes in the bottom of the nozzle were beneficial to obtain a uniform distribution of the fluid along the direction of roll width at the pool zone.