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  1. Article: Chemical reaction, Dufour and Soret effects on the stability of magnetohydrodynamic blood flow conveying magnetic nanoparticle in presence of thermal radiation: A biomedical application.

    Njingang Ketchate, Cédric Gervais / Tiam Kapen, Pascalin / Madiebie-Lambou, Inesse / Fokwa, Didier / Chegnimonhan, Victorin / Tchinda, René / Tchuen, Ghislain

    Heliyon

    2023  Volume 9, Issue 1, Page(s) e12962

    Abstract: Nowadays ferrofluids (magnetic nanofluids) are at the center of many researches because of their major biomedical applications such as drug delivery and cancer treatment. The effects of chemical reaction, temperature gradient induced mass transfer and ... ...

    Abstract Nowadays ferrofluids (magnetic nanofluids) are at the center of many researches because of their major biomedical applications such as drug delivery and cancer treatment. The effects of chemical reaction, temperature gradient induced mass transfer and concentration gradient induced heat transfer on the stability of ferrofluid flow are of great importance. This paper deals with a stability analysis of a ferrofluid composed of blood as base fluid and magnetic nanoparticles. The study integrates the effects of chemical reactions, the effects of mass transfer (Soret effect), the effects of heat transfer (Dufour effect) and the effects of the Buoyancy force. The flow is exposed to a magnetic field and thermal radiation. A system of eigenvalue equations governing the evolution of disturbances is derived by assuming a normal mode analysis. This system of equations is then solved numerically by the method of collocation. It appears from this study that the addition of nanoparticles to the blood increases its inertia, which dampens the amplitude of the disturbances and stabilizes the flow. The Casson parameter affects the stability of the flow by increasing the amplitude of the disturbances, which reflects its destabilizing effect. It appears from this study that taking into account the non-Newtonian nature of blood is very important when modeling the dynamics of the system because it shows more important and very different results than when blood is treated as a Newtonian fluid. The chemical reaction between the fluid and the nanoparticles leads to the redistribution of disturbances within the flow, which amplifies the instabilities and reflects the destabilizing character of the chemical reaction. On the other hand, temperature gradient induced mass transfer effects and concentration gradient induced heat transfer effects play an essential role on the stability of the flow because they attenuate the amplitude of the disturbances in the flow. The Darcy number exhibits a stabilizing effect on the flow. It appears from this analysis that the porosity of the medium increases the contact surface between the fluid and the nanoparticles. Buoyancy forces, thermal radiation parameter and wave number contribute to the stability of the flow. The magnetic field through the Lorentz force decreases the kinetic energy of the flow, which dissipates the disturbances and thus reflects the stabilizing character of the magnetic field. It should be noted that heat and mass transfer on magnetohydrodynamic flows through porous media taking into consideration the effect of chemical reaction appears in many natural and artificial transport processes in several branches of science and engineering applications. This phenomenon plays an important role in the chemical industry, power and cooling industry for drying, chemical vapor deposition on surfaces, cooling of nuclear reactors and petroleum industry. The effects of thermal radiation, mass and heat transfer are used in many situations in biomedical engineering and aerospace engineering.
    Language English
    Publishing date 2023-01-16
    Publishing country England
    Document type Journal Article
    ZDB-ID 2835763-2
    ISSN 2405-8440
    ISSN 2405-8440
    DOI 10.1016/j.heliyon.2023.e12962
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Chemical reaction, Dufour and Soret effects on the stability of magnetohydrodynamic blood flow conveying magnetic nanoparticle in presence of thermal radiation: A biomedical application

    Njingang Ketchate, Cédric Gervais / Tiam Kapen, Pascalin / Madiebie-Lambou, Inesse / Fokwa, Didier / Chegnimonhan, Victorin / Tchinda, René / Tchuen, Ghislain

    Heliyon. 2023 Jan., v. 9, no. 1 p.e12962-

    2023  

    Abstract: Nowadays ferrofluids (magnetic nanofluids) are at the center of many researches because of their major biomedical applications such as drug delivery and cancer treatment. The effects of chemical reaction, temperature gradient induced mass transfer and ... ...

    Abstract Nowadays ferrofluids (magnetic nanofluids) are at the center of many researches because of their major biomedical applications such as drug delivery and cancer treatment. The effects of chemical reaction, temperature gradient induced mass transfer and concentration gradient induced heat transfer on the stability of ferrofluid flow are of great importance. This paper deals with a stability analysis of a ferrofluid composed of blood as base fluid and magnetic nanoparticles. The study integrates the effects of chemical reactions, the effects of mass transfer (Soret effect), the effects of heat transfer (Dufour effect) and the effects of the Buoyancy force. The flow is exposed to a magnetic field and thermal radiation. A system of eigenvalue equations governing the evolution of disturbances is derived by assuming a normal mode analysis. This system of equations is then solved numerically by the method of collocation. It appears from this study that the addition of nanoparticles to the blood increases its inertia, which dampens the amplitude of the disturbances and stabilizes the flow. The Casson parameter affects the stability of the flow by increasing the amplitude of the disturbances, which reflects its destabilizing effect. It appears from this study that taking into account the non-Newtonian nature of blood is very important when modeling the dynamics of the system because it shows more important and very different results than when blood is treated as a Newtonian fluid. The chemical reaction between the fluid and the nanoparticles leads to the redistribution of disturbances within the flow, which amplifies the instabilities and reflects the destabilizing character of the chemical reaction. On the other hand, temperature gradient induced mass transfer effects and concentration gradient induced heat transfer effects play an essential role on the stability of the flow because they attenuate the amplitude of the disturbances in the flow. The Darcy number exhibits a stabilizing effect on the flow. It appears from this analysis that the porosity of the medium increases the contact surface between the fluid and the nanoparticles. Buoyancy forces, thermal radiation parameter and wave number contribute to the stability of the flow. The magnetic field through the Lorentz force decreases the kinetic energy of the flow, which dissipates the disturbances and thus reflects the stabilizing character of the magnetic field. It should be noted that heat and mass transfer on magnetohydrodynamic flows through porous media taking into consideration the effect of chemical reaction appears in many natural and artificial transport processes in several branches of science and engineering applications. This phenomenon plays an important role in the chemical industry, power and cooling industry for drying, chemical vapor deposition on surfaces, cooling of nuclear reactors and petroleum industry. The effects of thermal radiation, mass and heat transfer are used in many situations in biomedical engineering and aerospace engineering.
    Keywords blood ; blood flow ; cancer therapy ; chemical industry ; chemical reactions ; drugs ; evolution ; heat transfer ; kinetic energy ; magnetic fields ; mass transfer ; nanofluids ; nanoparticles ; petroleum ; porosity ; temperature ; thermal radiation ; vapors ; Chemical reaction ; Dufour effect ; Soret effect ; Ferrofluid ; Stabilty analysis
    Language English
    Dates of publication 2023-01
    Publishing place Elsevier Ltd
    Document type Article ; Online
    Note Pre-press version ; Use and reproduction
    ZDB-ID 2835763-2
    ISSN 2405-8440
    ISSN 2405-8440
    DOI 10.1016/j.heliyon.2023.e12962
    Database NAL-Catalogue (AGRICOLA)

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  3. Article ; Online: A comparative study between normal electrocardiogram signal and those of some cardiac arrhythmias based on McSharry mathematical model.

    Tiam Kapen, Pascalin / Kouam Kouam, Serge Urbain / Tchuen, Ghislain

    Australasian physical & engineering sciences in medicine

    2019  Volume 42, Issue 2, Page(s) 511–528

    Abstract: In this paper, synthetic electrocardiogram signals (SECG) of eight cardiac arrhythmias (sinus bradycardia, junctional bradycardia, tachycardia, flutter, atrial extrasystole, ventricular extrasystole, left branch block and right branch block) are obtained ...

    Abstract In this paper, synthetic electrocardiogram signals (SECG) of eight cardiac arrhythmias (sinus bradycardia, junctional bradycardia, tachycardia, flutter, atrial extrasystole, ventricular extrasystole, left branch block and right branch block) are obtained numerically by solving the McSharry mathematical model (2003) based on three coupled ordinary differential equations with the fourth-order Runge-Kutta method. They are compared with normal electrocardiogram signal. Indeed, visual analysis of a section of electrocardiogram (ECG) signals of these arrhythmias was used to suggest suitable values for the parameters in the McSharry mathematical model. Results from numerical simulation showed a good agreement between the simulation results and the real cardiac arrhythmias ECG signals.
    MeSH term(s) Arrhythmias, Cardiac/diagnostic imaging ; Computer Simulation ; Databases as Topic ; Electrocardiography ; Humans ; Models, Theoretical ; Signal Processing, Computer-Assisted
    Language English
    Publishing date 2019-04-02
    Publishing country Netherlands
    Document type Comparative Study ; Journal Article
    ZDB-ID 46226-3
    ISSN 1879-5447 ; 0158-9938
    ISSN (online) 1879-5447
    ISSN 0158-9938
    DOI 10.1007/s13246-019-00752-7
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: A multi-function neonatal incubator for low-income countries: Implementation and ab initio social impact.

    Tiam Kapen, Pascalin / Youssoufa, Mohamadou / Foutse, Momo / Dongmeza Koudjou, Jauspin / Mkankam Kamga, François de Paul

    Medical engineering & physics

    2020  Volume 77, Page(s) 114–117

    Abstract: The World health Organization estimates that about 8 million babies die prematurely worldwide. Most of these cases are found in low-income countries (LICs). The use of neonatal incubators has proven to be very useful in the reduction of infant mortality. ...

    Abstract The World health Organization estimates that about 8 million babies die prematurely worldwide. Most of these cases are found in low-income countries (LICs). The use of neonatal incubators has proven to be very useful in the reduction of infant mortality. However, access to this important medical device is not always easy in LICs. This article presents the implementation of a multi-function neonatal incubator with remote monitoring, fingerprint scanner, phototherapy, and heart rate monitoring. In this view, proportional integral (PI) control algorithm and an Android application were developed. Furthermore, an initial social impact of the implemented neonatal incubator usage was performed in some hospitals in Cameroon.
    MeSH term(s) Developing Countries/statistics & numerical data ; Hospitals/statistics & numerical data ; Humans ; Incubators, Infant/statistics & numerical data ; Infant, Newborn ; Social Change ; Surveys and Questionnaires
    Language English
    Publishing date 2020-01-11
    Publishing country England
    Document type Journal Article
    ZDB-ID 1181080-4
    ISSN 1873-4030 ; 1350-4533
    ISSN (online) 1873-4030
    ISSN 1350-4533
    DOI 10.1016/j.medengphy.2019.10.021
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: An automatic multipoint inoculator for the determination of minimum inhibitory concentrations (MICs) of antibiotics in low-income countries: a technical note.

    Tiam Kapen, Pascalin / Fotsing Kwetche, Pierre René / Youssoufa, Mohamadou / Kayo Mbomda, Wilfried Camille / Ketchogue, Romaric Martial / Ganwo Dongmo, Sandrine

    Australasian physical & engineering sciences in medicine

    2019  Volume 42, Issue 4, Page(s) 905–912

    Abstract: Multipoint inoculator is a laboratory equipment that is used to inoculate with a very high precision a certain number of microorganisms in culture media, in order to determine the minimum inhibitory concentrations (MICs) of antibiotics that would inhibit ...

    Abstract Multipoint inoculator is a laboratory equipment that is used to inoculate with a very high precision a certain number of microorganisms in culture media, in order to determine the minimum inhibitory concentrations (MICs) of antibiotics that would inhibit microbial growth. MICs values are crucial in the control of microbial drug-susceptibility profile for effective infectious disease control and microbial resistance stewardship. The complexity of multipoint inoculator makes it very rare or almost non-existent in developing countries laboratories. In this paper, a robust, precise and, above all, innovative automatic multipoint inoculator is developed. Otherwise, we have implemented double-sided plates with surface-mounted components. These components of Nano-electronics have the advantage that the electrical circuits do no longer have to be drilled, the components can be placed on both sides of the board, and the parasitic electrical inductances are reduced. The equipment enclosure in plexiglas facilitates its sterilization. The device carries Petri dishes that contain culture media, opens them and performs inoculation. It then closes and stores the preparations that are ready for incubation at optimal growth conditions. The present device inoculates at a given concentration of an antibiotic 21 microorganisms simultaneously.
    MeSH term(s) Anti-Bacterial Agents/analysis ; Automation ; Culture Media/chemistry ; Developing Countries ; Income ; Microbial Sensitivity Tests/instrumentation
    Chemical Substances Anti-Bacterial Agents ; Culture Media
    Language English
    Publishing date 2019-10-28
    Publishing country Netherlands
    Document type Letter
    ZDB-ID 46226-3
    ISSN 1879-5447 ; 0158-9938
    ISSN (online) 1879-5447
    ISSN 0158-9938
    DOI 10.1007/s13246-019-00812-y
    Database MEDical Literature Analysis and Retrieval System OnLINE

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