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1.
J Mech Behav Biomed Mater ; 150: 106265, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38035644

RESUMO

This research presents the mechanical behavior of blood flow through capillary having smooth inner surface. In this study modelling of blood flow via permeable and lubricated capillary caused by nutrients re-absorption has been done by the help of laws of momentum and mass. The nutrients re-absorption is assumed to be constant and inner walls of the capillary are smooth and slippery therefore slip condition on the velocity and constant rate in vertical direction at the wall has considered. The Kelvin Voigt model is employed to simulate blood flow via capillaries, and results for pressure, blood flow pattern, and shear force necessary for blood flow are discovered by recursive approach. Numerical results for nutrient re-absorption from the blood and impact of smooth and slippery surfaces on blood flow are shown through graphs. The novelty of the research invents that the smoothness and slickness of capillary wall is a crucial presumption to examine the blood as non-Newtonian fluid via capillary.


Assuntos
Capilares , Modelos Cardiovasculares , Capilares/fisiologia , Velocidade do Fluxo Sanguíneo/fisiologia , Hemodinâmica , Estresse Mecânico , Simulação por Computador
2.
J Biomech Eng ; 143(5)2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33462593

RESUMO

Mathematical modeling of mechanical system in microfluidics is an emerging area of interest in microscale engineering. Since microfluidic devices use the hair-like structure of artificial cilia for pumping, mixing, and sensing in different fields, electro-osmotic cilia-driven flow helps to generate the fluid velocity for the Newtonian and viscoelastic fluid. Due to the deployment of artificial ciliated walls, the present research reports the combined effect of an electro-osmotic flow and convective heat transfer on Jeffrey viscoelastic electrolytic fluid flow in a two-dimensional ciliated vertical channel. Heat generation/absorption and nonlinear radiation effects are included in the present mathematical model. After applying Debye-Huckel approximation and small Reynolds number approximation to momentum and energy equation, the system of nonlinear partial differential equation is reduced into nonhomogenous boundary value problem. The problem determines the velocity, pressure, and temperature profiles by the application of semi-analytical technique known as homotopy perturbation method (HPM) with the help of software Mathematica. The graphical results of the study suggest that HPM is a reliable methodology for thermo physical electro-osmotic rheological transport in microchannels.


Assuntos
Temperatura Alta , Reologia
3.
Math Biosci Eng ; 16(4): 2927-2941, 2019 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-31137243

RESUMO

This study shows the effects of magnetic field and copper nanoparticles on the flow of tangent hyperbolic fluid (blood) through a ciliated tube (fallopian tube). The present study will be very helpful for those patients who are facing blood clotting in fallopian tube that may cause for infertility or cancer. The nanoparticles and magnetic field are very helpful to break the clots in blood flowing in fallopian tube. Since blood flows in fallopian tube due to ciliary movement, therefore medicines containing copper nanoparticles and magnetic field with radiation therapy help to improve the patient. Ciliary movement has a particular pattern of motion i.e., metachronal wavy motion which helps to fluid flow. For the forced convective MHD flow of tangent hyperbolic nano-fluid, momentum and energy equations are solved by the small Reynolds' number approximation and Adomian decomposition method by constructing the recursive relation of ADM and solved by software "MATHEMATICA". The effects of parameters such as nanoparticle volume fraction, Hartmann number, entropy generation and Bejan's number have been discussed through graphs plotted in software "MATHEMATICA". It is found that blood flow is accelerated and heat transfer enhancement is maximum in the presence of nano particles, also magnetic effects accelerates the blood flow and help to enhance the heat transfer whereas the presence of porous medium increases the fluid's velocity and reduce the transfer of heat through fluid flow.


Assuntos
Cílios/fisiologia , Tubas Uterinas/fisiologia , Hidrodinâmica , Cobre , Fenômenos Eletromagnéticos , Doenças das Tubas Uterinas/terapia , Tubas Uterinas/irrigação sanguínea , Feminino , Hemodinâmica , Temperatura Alta/uso terapêutico , Humanos , Magnetoterapia/métodos , Conceitos Matemáticos , Nanopartículas Metálicas , Modelos Biológicos , Trombose/terapia
4.
Comput Methods Biomech Biomed Engin ; 22(7): 685-695, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30829056

RESUMO

Bionic systems frequently feature electromagnetic pumping and offer significant advantages over conventional designs via intelligent bio-inspired properties. Complex wall features observed in nature also provide efficient mechanisms which can be utilized in biomimetic designs. The characteristics of biological fluids are frequently non-Newtonian in nature. In many natural systems super-hydrophobic slip is witnessed. Motivated by these phenomena, in this paper, we discussed a mathematical model for the cilia-generated propulsion of an electrically-conducting viscoelastic physiological fluid in a ciliated channel under the action of magnetic field. The rheological behavior of the fluid is simulated with the Johnson-Segalman constitutive model which allows internal wall slip. The regular or coordinated movement of the ciliated edges (which line the internal walls of the channel) is represented by a metachronal wave motion in the horizontal direction which generates a two-dimensional velocity profile. This mechanism is imposed by a periodic boundary condition which generates propulsion in the channel flow. Under the classical lubrication approximation, the boundary value problem is non-dimensionalized and solved analytically with a perturbation technique. The influence of the geometric, rheological (slip and Weissenberg number) and magnetic parameters on velocity, pressure gradient and the pressure rise (evaluated via the stream function in symbolic software) are presented graphically and interpreted at length.


Assuntos
Líquidos Corporais/química , Cílios/fisiologia , Modelos Teóricos , Condutividade Elétrica , Reologia
5.
Springerplus ; 5(1): 1379, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27610298

RESUMO

The present study investigated the cilia induced flow of MHD Jeffrey fluid through an inclined tube. This study is carried out under the assumptions of long wavelength and low Reynolds number approximations. Exact solutions for the velocity profile, pressure rise, pressure gradient, volume flow rate and stream function are obtained. Effects of pertinent physical parameters on the computational results are presented graphically.

6.
Genet Mol Res ; 9(3): 1936-45, 2010 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-20882490

RESUMO

We compared DNA-based genetic diversity estimates with conventional estimates by investigating agronomically important traits in maize grown in the northwestern region of Pakistan. RAPD markers were used to characterize 10 commonly cultivated maize genotypes. The same material was tested for phenotypic variation of quantitative traits using replicated field trials. The genetic distances between pairs of genotypes using RAPD data were used to generate a similarity matrix and to construct a phenogram. Statistical analyses were carried out on the data obtained from field trials of all maize genotypes for days to 50% tasseling, days to 50% silking, plant height, ear height, grain yield, grain weight per cob, and ear length. Analysis of variance and single degree of freedom contrasts were performed on morphological data to examine the relationship between molecular-based clusters and agronomic traits. A molecular marker-based phenogram led to the grouping of all genotypes into four major clusters, some of which were distantly related. These clusters contained one to four genotypes. Analysis of variance showed significant variations among all genotypes for agronomic traits. The single degree of freedom contrasts between groups of genotypes indicated significant differences for most traits. Pair-wise comparisons between clusters were also significant. The two types of data correlated well, providing an opportunity for better choices for selection.


Assuntos
Marcadores Genéticos/genética , Zea mays/genética , Variação Genética/genética , Genótipo , Paquistão , Técnica de Amplificação ao Acaso de DNA Polimórfico
7.
J Trop Med Hyg ; 83(6): 251-3, 1980 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7441802

RESUMO

In a retrospective analysis of 1000 diabetic patients attending an out-patient clinic in a Lahore Hospital, hypertension was present in 26 x 4 per cent. There was a female preponderance in the overall group and the male; female ratio was similar in the sub group with hypertension. In our assessment the overall contribution of diabetic renal disease to the prevalence of hypertension was unimpressive. The hypertension was mild in a vast majority of patients.


Assuntos
Complicações do Diabetes , Hipertensão/complicações , Adulto , Diabetes Mellitus/epidemiologia , Feminino , Humanos , Hipertensão/epidemiologia , Masculino , Pessoa de Meia-Idade , Paquistão , Estudos Retrospectivos
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