scholarly journals Sanal Flow Choking in Nanoscale Fluid Flow Systems at the Zero Slip Length: Universal Benchmark Data for 3D in Silico, in Vitro and in Vivo Experiments 

2021 ◽  
Author(s):  
V R Sanal Kumar ◽  
Vigneshwaran Sankar ◽  
Nichith Chandrasekaran ◽  
Sulthan Ariff Rahman Mohamed Rafic ◽  
Ajith Sukumaran ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Fluid Flow ◽  
Closed Form ◽  
Slip Length ◽  
Pressure Ratio ◽  
Flow Choking ◽  
Benchmark Data ◽  
Nanoscale Fluid Flow

Abstract Although the interdisciplinary science of nanotechnology has been advanced significantly over the last few decades there were no closed-form analytical models to predict the three-dimensional (3D) boundary-layer-blockage (BLB) factor, of diabatic flows (flows involves the transfer of heat) passing through a nanoscale tube. As the pressure of the diabatic nanofluid and/or non-continuum-flows rises, average-mean-free-path diminishes and thus, the Knudsen number lowers heading to a zero-slip wall-boundary condition with the compressible viscous flow regime in the nano scale tubes leading to Sanal flow choking [PMCID: PMC7267099; Physics of Fluids, DOI: 10.1063/5.0040440] creating a physical situation of the sonic-fluid-throat effect in the tube at a critical-total-to-static pressure ratio (CPR). Herein, we presented a closed-form-analytical-model, which is capable to predict exactly the 3D-BLB factor at the Sanal flow choking-condition of nanoscale diabatic fluid flow systems at the zero-slip-length. The innovation of Sanal flow choking model in the nanoscale fluid flow system is established herein through the entropy relation, as it satisfies all the conservation laws of nature. The exact value of the 3D-BLB factor in the sonic-fluid-throat region presented herein for each gas is a universal benchmark data for performing high-fidelity in silico, in vitro and in vivo experiments for the lucrative design optimization of nanoscale fluid flow systems in gravity and microgravity environments and also for drug discovery for prohibiting asymptomatic cardiovascular diseases in Earth and human spaceflight <doi.org/10.2514/6.2021-0357>. Note that the relatively high and low-blood-viscosity (creating high turbulence) leads to the Sanal flow choking causing asymptomatic cardiovascular diseases. Such diseases in the cardiovascular system can be negated by maintaining the systolic-to-diastolic blood pressure ratio lower than the CPR <10.1002/gch2.202000076>. The CPR is regulated by the heat capacity ratio (HCR) of the fluid. Note that HCR is the key parameter, which could control simultaneously blood viscosity and turbulence. The physical insight of the boundary-layer-blockage persuaded nanoscale Sanal flow choking in diabatic flows presented in this article sheds light on finding solutions to numerous unresolved scientific problems in physical, chemical and biological systems carried forward over the centuries because the closed-form analytical model describing the phenomenon of Sanal flow choking is a unique scientific language of the real-world-fluid flows. More specifically, mathematical models presented herein are capable to forecast the limiting conditions of deflagration to detonation transition (DDT) in nanoscale systems and beyond with confidence. Additionally, the Sanal flow choking condition will forecast the asymptomatic-hemorrhage and acute-heart-failure https://www.ahajournals.org/doi/10.1161/str.52.suppl_1.P804. Briefly, the undesirable Sanal flow choking causing detonation and hemorrhagic stroke can be negated by increasing the HCR of the fluid.

Nanoscale Flow Choking at the Zero Slip Length: Universal Benchmark Data for In Silico Experiments

2020 ◽  
Author(s):  
V R Sanal Kumar ◽  
Vigneshwaran Sankar ◽  
Nichith Chandrasekaran ◽  
Sulthan Ariff Rahman Mohamed Rafic ◽  
Ajith Sukumaran ◽  
...  
Keyword(s):  
Boundary Layer ◽  
In Silico ◽  
Slip Length ◽  
Pressure Ratio ◽  
Physical Situation ◽  
Nanoscale Systems ◽  
Flow Choking ◽  
Benchmark Data ◽  
Displacement Thickness

Abstract The Sanal flow choking (PMCID: PMC7267099) and the streamtube flow choking are new theoretical concepts applicable to both the continuum and non-continuum fluid flows. Once the streamlines compacted, the considerable pressure difference attains within the streamtube and the flow within the streamtube gets accelerated to the constricted section for satisfying the continuity condition set up the conservation law of nature, which leads to the Sanal flow choking and supersonic flow development at a critical-total-to-static pressure ratio (CPR) due to the convergent-divergent (CD) shape of the streamtube. As the pressure of the nanofluid/non-continuum-flows rises, average-mean-free-path diminishes and thus, the Knudsen number lowers heading to a zero-slip wall-boundary condition with compressible viscous (CV) flow regime. Sanal flow choking is a CV flow phenomenon creating a physical situation of the sonic-fluid-throat in a duct at a CPR. Herein, we presented a closed-form-analytical-model, which is capable to predict exactly the three-dimensional boundary-layer-displacement-thickness of nanoscale diabatic fluid flow (flow involves transfer of heat) systems at the zero-slip-length. The innovation of Sanal flow choking model is established herein through the entropy relation, as it satisfies all the conservation laws of nature. The exact value of the 3D boundary-layer-displacement-thickness in the sonic-fluid-throat region presented herein for each gas is a universal benchmark data for performing high-fidelity in vitro and in silico experiments for the lucrative design optimization of nanoscale systems. The physical insight of the Sanal flow choking and streamtube flow choking presented in this letter sheds light on finding solutions for numerous unresolved scientific problems.

scholarly journals Discovery of nanoscale sanal flow choking in cardiovascular system: exact prediction of the 3D boundary-layer-blockage factor in nanotubes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
V. R. Sanal Kumar ◽  
Vigneshwaran Sankar ◽  
Nichith Chandrasekaran ◽  
Sulthan Ariff Rahman Mohamed Rafic ◽  
Ajith Sukumaran ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Mathematical Model ◽  
Fluid Flow ◽  
Real World ◽  
Diastolic Pressure ◽  
Pressure Ratio ◽  
Flow Choking ◽  
The Real ◽  
Blockage Factor ◽  
Flow Systems

AbstractEvidences are escalating on the diverse neurological-disorders and asymptomatic cardiovascular-diseases associated with COVID-19 pandemic due to the Sanal-flow-choking. Herein, we established the proof of the concept of nanoscale Sanal-flow-choking in real-world fluid-flow systems using a closed-form-analytical-model. This mathematical-model is capable of predicting exactly the 3D-boundary-layer-blockage factor of nanoscale diabatic-fluid-flow systems (flow involves the transfer of heat) at the Sanal-flow-choking condition. As the pressure of the diabatic nanofluid and/or non-continuum-flows rises, average-mean-free-path diminishes and thus, the Knudsen-number lowers heading to a zero-slip wall-boundary condition with the compressible-viscous-flow regime in the nanoscale-tubes leading to Sanal-flow-choking due to the sonic-fluid-throat effect. At the Sanal-flow-choking condition the total-to-static pressure ratio (ie., systolic-to-diastolic pressure ratio) is a unique function of the heat-capacity-ratio of the real-world flows. The innovation of the nanoscale Sanal-flow-choking model is established herein through the entropy relation, as it satisfies all the conservation-laws of nature. The physical insight of the boundary-layer-blockage persuaded nanoscale Sanal-flow-choking in diabatic flows presented in this article sheds light on finding solutions to numerous unresolved scientific problems in physical, chemical and biological sciences carried forward over the centuries because the mathematical-model describing the phenomenon of Sanal-flow-choking is a unique scientific-language of the real-world-fluid flows. The 3D-boundary-layer-blockage factors presented herein for various gases are universal-benchmark-data for performing high-fidelity in silico, in vitro and in vivo experiments in nanotubes.

scholarly journals O23: CHARACTERISING PATIENT-DERIVED COLORECTAL CANCER TISSUE-ORIGINATED ORGANOIDAL SPHEROIDS FOR HIGH-THROUGHPUT MICROFLUIDIC APPLICATIONS

2021 ◽  
Vol 108 (Supplement_1) ◽  
Author(s):  
MI Khot ◽  
M Levenstein ◽  
R Coppo ◽  
J Kondo ◽  
M Inoue ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Fluid Flow ◽  
High Throughput ◽  
Microfluidic Devices ◽  
In Vitro Models ◽  
Fluorescent Imaging ◽  
Cancer Tissue ◽  
Cell Models

Abstract Introduction Three-dimensional (3D) cell models have gained reputation as better representations of in vivo cancers as compared to monolayered cultures. Recently, patient tumour tissue-derived organoids have advanced the scope of complex in vitro models, by allowing patient-specific tumour cultures to be generated for developing new medicines and patient-tailored treatments. Integrating 3D cell and organoid culturing into microfluidics, can streamline traditional protocols and allow complex and precise high-throughput experiments to be performed with ease. Method Patient-derived colorectal cancer tissue-originated organoidal spheroids (CTOS) cultures were acquired from Kyoto University, Japan. CTOS were cultured in Matrigel and stem-cell media. CTOS were treated with 5-fluorouracil and cytotoxicity evaluated via fluorescent imaging and ATP assay. CTOS were embedded, sectioned and subjected to H&E staining and immunofluorescence for ABCG2 and Ki67 proteins. HT29 colorectal cancer spheroids were produced on microfluidic devices using cell suspensions and subjected to 5-fluorouracil treatment via fluid flow. Cytotoxicity was evaluated through fluorescent imaging and LDH assay. Result 5-fluorouracil dose-dependent reduction in cell viability was observed in CTOS cultures (p&lt;0.01). Colorectal CTOS cultures retained the histology, tissue architecture and protein expression of the colonic epithelial structure. Uniform 3D HT29 spheroids were generated in the microfluidic devices. 5-fluorouracil treatment of spheroids and cytotoxic analysis was achieved conveniently through fluid flow. Conclusion Patient-derived CTOS are better complex models of in vivo cancers than 3D cell models and can improve the clinical translation of novel treatments. Microfluidics can streamline high-throughput screening and reduce the practical difficulties of conventional organoid and 3D cell culturing. Take-home message Organoids are the most advanced in vitro models of clinical cancers. Microfluidics can streamline and improve traditional laboratory experiments.

In Vitro Experimental Investigation of the Integrity of the Stem–Cement Interface

2013 ◽  
Vol 647 ◽  
pp. 53-56
Author(s):  
Hong Yu Zhang ◽  
Leigh Fleming ◽  
Liam Blunt
Keyword(s):  
Experimental Investigation ◽  
Fluid Flow ◽  
Hip Replacement ◽  
Hip Prosthesis ◽  
Vitro Experiment ◽  
Cement Interface ◽  
In Vitro Experiment ◽  
Mechanical Bonding

The rationale behind failure of cemented total hip replacement is still far from being well understood in a mechanical and molecular perspective. In the present study, the integrity of the stem–cement interface was investigated through an in vitro experiment monitoring fluid flow along this interface. The results indicated that a good mechanical bonding formed at the stem–cement interface before debonding of this interface was induced by physiological loadings during the in vivo service of the hip prosthesis.

In vivo and in vitro study of enamel fluid flow in human premolars

2020 ◽  
Vol 117 ◽  
pp. 104795 ◽  
Author(s):  
Rathirach Tanapitchpong ◽  
Ekachai Chunhacheevachaloke ◽  
Orapin Ajcharanukul
Keyword(s):  
Fluid Flow ◽  
In Vitro Study ◽  
Vitro Study

scholarly journals Embryonic nodal flow and the dynamics of nodal vesicular parcels

2006 ◽  
Vol 4 (12) ◽  
pp. 49-56 ◽  
Author(s):  
Julyan H.E Cartwright ◽  
Nicolas Piro ◽  
Oreste Piro ◽  
Idan Tuval
Keyword(s):  
Fluid Flow ◽  
Closed System ◽  
Biochemical Mechanism ◽  
Numerical Techniques ◽  
Biophysical Properties ◽  
Nodal Flow ◽  
Dynamical Simulations ◽  
Mechanical Rupture

We address with fluid-dynamical simulations using direct numerical techniques three important and fundamental questions with respect to fluid flow within the mouse node and left–right development. First, we consider the differences between what is experimentally observed when assessing cilium-induced fluid flow in the mouse node in vitro and what is to be expected in vivo . The distinction is that in vivo , the leftward fluid flow across the mouse node takes place within a closed system and is consequently confined, while this is no longer the case on removing the covering membrane and immersing the embryo in a fluid-filled volume to perform in vitro experiments. Although there is a central leftward flow in both instances, we elucidate some important distinctions about the closed in vivo situation. Second, we model the movement of the newly discovered nodal vesicular parcels (NVPs) across the node and demonstrate that the flow should indeed cause them to accumulate on the left side of the node, as required for symmetry breaking. Third, we discuss the rupture of NVPs. Based on the biophysical properties of these vesicles, we argue that the morphogens they contain are likely not delivered to the surrounding cells by their mechanical rupture either by the cilia or the flow, and rupture must instead be induced by an as yet undiscovered biochemical mechanism.

Review of the fluid flow within intervertebral discs - How could in vitro measurements replicate in vivo?

2016 ◽  
Vol 49 (14) ◽  
pp. 3133-3146 ◽  
Author(s):  
Hendrik Schmidt ◽  
Sandra Reitmaier ◽  
Friedmar Graichen ◽  
Aboulfazl Shirazi-Adl
Keyword(s):  
Fluid Flow ◽  
Intervertebral Discs ◽  
In Vitro Measurements

scholarly journals Abstract P804: Lopsided Blood-Thinning Drug Increases the Risk of Internal Flow Choking and Shock Wave Generation Causing Asymptomatic Stroke

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Sanal Kumar V R ◽  
Keyword(s):  
Shock Wave ◽  
In Silico ◽  
Healthy Subjects ◽  
Pressure Ratio ◽  
Internal Flow ◽  
Wave Generation ◽  
Analytical Models ◽  
Flow Choking ◽  
Shock Wave Generation

Introduction: Consequence of lopsided blood-thinning-drug, lowering blood-viscosity (BV), is bleeding and very frequently asymptomatic-hemorrhage (AH) and the acute-heart-failure (AHF) happen. V.R.S.Kumar et al. (2020) reported that such asymptomatic episodes are due to the internal flow choking in the cardiovascular system (CVS) at a critical blood pressure ratio (BPR), which is regulated by biofluid/blood heat capacity ratio (BHCR). Methods: The closed-form-analytical-methodology is used for correlating BV, BPR, BHCR, vessel geometry and ejection fraction (EF). In vitro method is used for the BHCR estimation of healthy subjects. In silico method is used for demonstrating the Sanal flow choking. Results: The analytical models reveal that the relatively high and low BV are risk factors of internal flow choking. In vitro study shows that N 2 , O 2 , CO 2 & Ar gases are predominant in fresh-blood samples of the healthy subjects at a temperature range of 37-40 0 C (98.6-104 0 F), which increases the risk of flow-choking. In silico results demonstrated the Sanal flow choking followed by the shock wave generation and pressure-overshoot in a simulated artery with the divergent/bifurcation region. Conclusions: An overdose of blood-thinning drug reduces BV and increases Reynolds number causing high-turbulence leading to the Sanal flow choking. Asymptomatic stroke could be diminished by concurrently lessening the BV and flow turbulence by rising thermal tolerance level in terms of BHCR or by decreasing the BPR. In conclusion, BPR must always be lower than 1.8257 as dictated by the lowest BHCR of the evolved gas (CO 2 ) for prohibiting asymptomatic stroke.

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