scholarly journals Microrheometer for Biofluidic Analysis: Electronic Detection of the Fluid-Front Advancement

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 726
Author(s):  
Lourdes Méndez-Mora ◽  
Maria Cabello-Fusarés ◽  
Josep Ferré-Torres ◽  
Carla Riera-Llobet ◽  
Samantha Lopez ◽  
...  
Keyword(s):  
Point Of Care ◽  
Front Velocity ◽  
Newtonian Fluids ◽  
Rheological Characterization ◽  
Blood Samples ◽  
Shear Rates ◽  
Air Interface ◽  
Healthy Donors ◽  
Different Characteristics

The motivation for this study was to develop a microdevice for the precise rheological characterization of biofluids, especially blood. The method presented was based on the principles of rheometry and fluid mechanics at the microscale. Traditional rheometers require a considerable amount of space, are expensive, and require a large volume of sample. A mathematical model was developed that, combined with a proper experimental model, allowed us to characterize the viscosity of Newtonian and non-Newtonian fluids at different shear rates. The technology presented here is the basis of a point-of-care device capable of describing the nonlinear rheology of biofluids by the fluid/air interface front velocity characterization through a microchannel. The proposed microrheometer uses a small amount of sample to deliver fast and accurate results, without needing a large laboratory space. Blood samples from healthy donors at distinct hematocrit percentages were the non-Newtonian fluid selected for the study. Water and plasma were employed as testing Newtonian fluids for validation of the system. The viscosity results obtained for the Newtonian and non-Newtonian fluids were consistent with pertinent studies cited in this paper. In addition, the results achieved using the proposed method allowed distinguishing between blood samples with different characteristics.

Numerical Simulations of a Centrifugal Pump With a Non-Newtonian Fluid: Influence on Performances of Different Rheological Modelling

2019 ◽  
Author(s):  
Matteo Occari ◽  
Valentina Mazzanti ◽  
Francesco Mollica ◽  
Enrico Munari ◽  
Michele Pinelli ◽  
...  
Keyword(s):  
Experimental Tests ◽  
Newtonian Fluids ◽  
Centrifugal Pumps ◽  
Rheological Characterization ◽  
Rate Range ◽  
Shear Rates ◽  
Rheological Modelling ◽  
Pear Juice ◽  
Dynamics Simulations

Abstract Centrifugal pumps change their performance with respect to water when processing non-Newtonian fluids. Many aspects about pumping of non-Newtonian fluids remain to be clarified due to complexity of the matter and the scarcity of investigations. In addition to experimental tests, in recent years some CFD fluid dynamics simulations have been realized to analyze the performance of centrifugal pumps with non-Newtonian fluids. Knowledge of rheology is required to correctly simulate the fluid inside the pump and predict the performance. The aim of this work is to emphasize the criticalities in the simulation of centrifugal pumps with non-Newtonian fluids, since, starting from the same rheological data, can be deduced different rheological laws, however reliable, that produce different effects on the simulations. In this paper, the performances of a model pump were measured experimentally with pear juice and accompanied by the rheological characterization of the fluid. Subsequently, the pump was simulated using five different rheology laws, all fitted to the same experimental rheogram, that differ from each other in predicting viscosity out of shear rate range experimentally measured. The pump performances were affected by the different rheology implemented. The simulations showed that the shear rates developed inside the pump are much higher than those measured with the rheometer. Consequently is necessary to achieve higher shear rates in the experimental rheogram to make sure to correctly model the rheology for shear rates values typically present in the pump.

scholarly journals Characterization of carbon-coated magnetic nanoparticles using clinical blood coagulation assays: effect of PEG-functionalization and comparison to silica nanoparticles

2014 ◽  
Vol 2 (24) ◽  
pp. 3753-3758 ◽  
Author(s):  
Lukas Bircher ◽  
Oliver M. Theusinger ◽  
Silvan Locher ◽  
Philipp Eugster ◽  
Birgit Roth-Z'graggen ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Blood Coagulation ◽  
Human Blood ◽  
Point Of Care ◽  
Blood Samples ◽  
Coagulation Assays ◽  
Carbon Coated ◽  
Human Blood Samples ◽  
Peg Functionalization

We use point-of-care-assays to study blood coagulation in human blood samples exposed to nanomagnets.

scholarly journals Blood Rheological Characterization of β-Thalassemia Trait and Iron Deficiency Anemia Using Front Microrheometry

2021 ◽  
Vol 12 ◽  
Author(s):  
Lourdes Méndez-Mora ◽  
Maria Cabello-Fusarés ◽  
Josep Ferré-Torres ◽  
Carla Riera-Llobet ◽  
Elena Krishnevskaya ◽  
...  
Keyword(s):  
Iron Deficiency ◽  
Iron Deficiency Anemia ◽  
Microfluidic Channel ◽  
Deficiency Anemia ◽  
Beta Thalassemia ◽  
Rheological Characterization ◽  
Gold Standard Method ◽  
Healthy Donors ◽  
Thalassemia Trait

The purpose of this work is to develop a hematocrit-independent method for the detection of beta-thalassemia trait (β-TT) and iron deficiency anemia (IDA), through the rheological characterization of whole blood samples from different donors. The results obtained herein are the basis for the development of a front microrheometry point-of-care device for the diagnosis and clinical follow-up of β-TT patients suffering hematological diseases and alterations in the morphology of the red blood cell (RBC). The viscosity is calculated as a function of the mean front velocity by detecting the sample fluid-air interface advancing through a microfluidic channel. Different viscosity curves are obtained for healthy donors, β-TT and IDA samples. A mathematical model is introduced to compare samples of distinct hematocrit, classifying the viscosity curve patterns with respect to the health condition of blood. The viscosity of the fluid at certain shear rate values varies depending on several RBC factors such as shape and size, hemoglobin (Hb) content, membrane rigidity and hematocrit concentration. Blood and plasma from healthy donors are used as reference. To validate their potential clinical value as a diagnostic tool, the viscosity results are compared to those obtained by the gold-standard method for RBC deformability evaluation, the Laser-Optical Rotational Red Cell Analyzer (LoRRCA).

Rheological Characterization of Shear-Thinning Fluids with a Novel Viscosity Equation of a Tank-Tube Viscometer

2007 ◽  
Vol 17 (5) ◽  
pp. 51413-1-51413-9
Author(s):  
Kyung C. Kwon ◽  
YoonKook Park ◽  
Tamara Floyd ◽  
Nader Vahdat ◽  
Erica Jackson ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Polyethylene Oxide ◽  
Flow Characteristics ◽  
Newtonian Fluids ◽  
Newtonian Viscosity ◽  
Rheological Characterization ◽  
Rate Range ◽  
Shear Thinning Fluids

Abstract A tank-tube viscometer and its novel viscosity equation were developed to determine flow characteristics of non-Newtonian fluids. The objective of this research is to test capabilities of the tank-tube viscometer and its novel non-Newtonian viscosity equation by characterizing rheological behaviors of well-known polyethylene oxide (MW 8000000) aqueous solutions as non-Newtonian fluids with 60-w% sucrose aqueous solution as a reference calibration fluid. Non-Newtonian characteristics of 0.3 - 0.7 wt% polyethylene oxide aqueous solutions were extensively investigated with the tank-tube viscometer and its non-Newtonian viscosity equation over the 294 - 306 K temperature range, and 55 - 784 s-1 shear rate range. The 60-w% sucrose aqueous solution was used as a reference/calibration fluid for the tank-tube viscometer. Dynamic viscosity values of 60 w% sucrose aqueous solution were determined with the calibrated tank-tube viscometer and its Newtonian viscosity equation at 299.15 K, and compared with the literature values.

RHEOLOGICAL CHARACTERIZATION OF NON-NEWTONIAN FLUIDS WITH A NOVEL VISCOMETER

2008 ◽  
Vol 195 (6) ◽  
pp. 687-705 ◽  
Author(s):  
Kyung C. Kwon ◽  
Yoonkook Park ◽  
Tamara Floyd-Smith ◽  
Nader Vahdat ◽  
Erica Jackson ◽  
...  
Keyword(s):  
Newtonian Fluids ◽  
Rheological Characterization

scholarly journals Viscosity and Rheological Properties of Graphene Nanopowders Nanofluids

Entropy ◽  
2021 ◽  
Vol 23 (8) ◽  
pp. 979
Author(s):  
Abderrahim Bakak ◽  
Mohamed Lotfi ◽  
Rodolphe Heyd ◽  
Amine Ammar ◽  
Abdelaziz Koumina
Keyword(s):  
Shear Rate ◽  
Rheological Properties ◽  
Dynamic Viscosity ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Heat Extraction ◽  
Rheological Characterization ◽  
Shear Rates ◽  
Rheological Measurements

The dynamic viscosity and rheological properties of two different non-aqueous graphene nano-plates-based nanofluids are experimentally investigated in this paper, focusing on the effects of solid volume fraction and shear rate. For each nanofluid, four solid volume fractions have been considered ranging from 0.1% to 1%. The rheological characterization of the suspensions was performed at 20 ∘C, with shear rates ranging from 10−1s−1 to 103s−1, using a cone-plate rheometer. The Carreau–Yasuda model has been successfully applied to fit most of the rheological measurements. Although it is very common to observe an increase of the viscosity with the solid volume fraction, we still found here that the addition of nanoparticles produces lubrication effects in some cases. Such a result could be very helpful in the domain of heat extraction applications. The dependence of dynamic viscosity with graphene volume fraction was analyzed using the model of Vallejo et al.

The detection of circulating tumor cells in patients with renal cell carcinoma using the AccuCyte platform and customized markers.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e21148-e21148
Author(s):  
Arturo Ramirez ◽  
Scott S. Tykodi ◽  
Sherry Huang ◽  
Nicholas Alan Drovetto ◽  
Jackie L. Stilwell
Keyword(s):  
Renal Cell Carcinoma ◽  
Blood Cell ◽  
Cell Carcinoma ◽  
Tumor Cells ◽  
Circulating Tumor Cells ◽  
Peripheral Blood ◽  
Renal Cell ◽  
Blood Samples ◽  
Healthy Donors

e21148 Background: Enumeration of circulating tumor cells (CTCs) in peripheral blood represents a prognostic marker for select solid tumors. Commercially available technologies for CTC detection rely on enrichment of EpCAM-expressing cells. However, not all tumor histologies demonstrate high constitutive EpCAM expression, including renal cell carcinoma (RCC). New techniques for more complex immunophenotypic characterization of CTCs are therefore of great interest. Methods: The AccuCyte system for characterization of rare blood cell populations retains all nucleated cells for analysis. Fluorochrome-conjugated monoclonal antibodies (mAbs) are added to 3 ml peripheral blood samples processed by density separation with a specialized tube and float. Centrifugation deposits all nucleated cells (Buffy coat) onto a surface designed for imaging with an automated fluorescence microscope. Sensitivity for CTC identification was measured by spiking blood from healthy donors with defined numbers of MDA-MD-453 breast tumor cells analyzed with mAbs to EpCAM and CD45. Peripheral blood samples from 4 patients (pts) with metastatic RCC and whose primary tumor had been resected were analyzed with a mAb specific for the RCC-associated antigen carbonic anhydrase IX (CAIX), as well as mAbs for CD10, EGFR and EpCAM. Results: In 13 blood samples from healthy donors, an average of 89% of spiked-in MDA-MD-453 tumor cells defined as EpCAM+/CD45- were detected by AccuCyte analysis with linearity from 0 to 139 cells (slope=0.8899; r2=0.9351) and a sensitivity of approximately 1 CTC per 106 nucleated blood cells. 3 of 4 peripheral blood samples from pts with clear cell RCC contained putative CTCs (range 1-6 cells/ml) defined as CD45-/CAIX+ nucleated cells. 3 CTCs from one patient were also CD10+ or EGFR+. All putative CTCs were EpCAM-. Conclusions: The detection of EpCAM-/CAIX+ cells in RCC pts demonstrates the adaptability of the AccuCyte platform for CTC (or other rare blood cell) identification defined by customized markers. Further development of marker panels for CTC analyses in pts with RCC and other tumor histologies as well as automation of image analysis is ongoing.

scholarly journals Influence of dietary fiber addition on some properties of yoghurt

2013 ◽  
Vol 24 (1) ◽  
pp. 17-20 ◽  
Author(s):  
Cristina Damian
Keyword(s):  
Rheological Properties ◽  
Dietary Fiber ◽  
Newtonian Fluids ◽  
Dietary Fibers ◽  
Rheological Characterization ◽  
Rotational Viscometer ◽  
Cheap Method ◽  
Fiber Addition

AbstractThe objective of this work was to study the effect of different dietary fibers on rheological properties of yoghurts fortified with these fibers [1, 2, 3]. Commercial fibers from apple and inulin were used. The effect of addition of dietary fibers in yoghurt [4, 5] was investigated by a rotational viscometer, Brookfield viscometer (Brookfield Engineering Inc., Model RV-DV I Prime) with RV spindles. The Brookfield viscometer DV I Prime with disk spindles represents an easy and cheap method for rheological characterization of non-Newtonian fluids, in this case of yoghurt. Syneresis and pH did not show any difference, while only apple fiber yoghurt showed colour differences compared to control.

Rheological characterization of tack and viscoelasticity of compositions of crepe coating used in the Yankee dryer

TAPPI Journal ◽  
2019 ◽  
Vol 18 (11) ◽  
pp. 641-649
Author(s):  
JOSHUA OMAMBALA ◽  
CARL MCINTYRE
Keyword(s):  
Normal Force ◽  
Weight Ratio ◽  
Good Combination ◽  
Rheological Characterization ◽  
Nonlinear Viscoelastic ◽  
Coating Composition ◽  
Linear And Nonlinear ◽  
Work Done ◽  
Tissue Production

The vast majority of tissue production uses creping to achieve the required set of properties on the base sheet. The Yankee coating helps to develop the desired crepe that in turn determines properties such as bulk and softness. The adhesion of the sheet to the Yankee surface is a very important characteristic to consider in achieving the desired crepe. The coating mix usually consists of the adhesive, modifier, and release. A good combination of these components is essential to achieving the desired properties of the tissue or towel, which often are determined by trials on the machine that can be time consuming and lead to costly rejects. In this paper, five compositions of an industrial Yankee coating adhesive, modifier, and release were examined rheologically. The weight ratio of the adhesive was kept constant at 30% in all five compositions and the modifier and release ratios were varied. The normal force and work done by the different compositions have been shown at various temperatures simulating that of the Yankee surface, and the oscillatory test was carried out to explain the linear and nonlinear viscoelastic characteristic of the optimal coating composition.

CHEMICAL AND RHEOLOGICAL CHARACTERIZATION OF A VEGETABLE-BASED EMULSION

2019 ◽  
Author(s):  
Luiz Eduardo Rodrigues Vieira ◽  
Leonardo Rosa Ribeiro da Silva ◽  
Felipe Chagas Rodrigues de Souza ◽  
Wisley Sales ◽  
Álisson Rocha Machado
Keyword(s):  
Rheological Characterization
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