3,350 research outputs found
SYNTHESIS CHARACTERISATION AND BIOLOGICAL EVALUATION OF (3Z, 4Z)-3, 4-BIS (SUBSTITUTED PHENYL BENZYLIDINE)-1-(4-SUBTITUTED PHENYL) PYROLIDINE-2, 5-DIONE
Objective: The present study focuses on synthesis and characterization of new series of bis-chalcone derivatives from cyclic imides and evaluating its antimicrobial activity against a pathogenic microorganism.Methods: The substituted cyclic imides 4-methyl phenyl pyrrolidine 2,5 dione 1 and 4-methoxy phenyl pyrrolidine 2,5 dione 2 were synthesized from succinic acid and primary aromatic amines. These cyclic imides condensed with substituted benzaldehydes in the presence of acetic acid furnished bis-heterocyclic chalcones and characterized by FT-IR, 1H NMR and also microbial activity was determined using the disc diffusion method.Results: The antimicrobial activity of bis-heterocyclic chalcones was tested against selective pathogens and the zone of inhibition was observed in E. coli, C. albicans and A. niger at 100µg/ml concentration.Conclusion: The compound (3Z,4Z)-3,4-bis-(2-hydroxybenzylidine)-1-p-tolylpyrrolidine-2,5-dione (3b) with methyl and hydroxyl substituent on benzene ring exhibited good antibacterial activity against E. coli and potent antifungal activity against C. albicans and A. niger.Keywords: Succinic acid, Cyclic imides, Pyrrolidine-2,5-dione, Bis-chalcon
Effect of rotation on anisotropic scattering suspension of phototactic algae
In this article, the effect of rotation on the onset of phototactic
bioconvection is investigated using linear stability theory for a suspension of
forward-scattering phototactic algae in this article. The suspension is
uniformly illuminated by collimated flux. The bio-convective instability is
characterized by an unstable mode of disturbance that transitions from a
stationary (overstable) to an overstable (stationary) state as the Taylor
number varies under fixed parameters. It is also observed that the suspension
has significant stabilizing effect due to rotation of the system
Effect of forward scattering and rigid top surface on the onset of phototactic bioconvection in an algal suspension illuminated by both oblique collimated and diffuse irradiation
The effect of the rigid top surface on the onset of phototactic bioconvection
is investigated using linear stability theory for a suspension of
forward-scattering phototactic algae in this article. The suspension is
uniformly illuminated by both diffuse and oblique collimated flux. The nature
of disturbance of bio-convective instability transits from a stationary
(overstable) to an overstable (stationary) state as the forward scattering
coefficient varies under fixed parameters. In presence of rigid top surface,
the suspension becomes more stable as the forward scattering coefficient
increases
Unified Angular Momentum of Dyons
Unified quaternionic angular momentum for the fields of dyons and
gravito-dyons has been developed and the commutation relations for dynamical
variables are obtained in compact and consistent manner. Demonstrating the
quaternion forms of unified fields of dyons (electromagnetic fields) and
gravito-dyons (gravito-Heavisidian fields of linear gravity), corresponding
quantum equations are reformulated in compact, simpler and manifestly covariant
way
Phototactic bioconvection with the effect of oblique collimated flux at forward scattering algae suspension in rotating medium
The primary objective of this article is to explore how rotation influences
the initiation of phototactic bioconvection. This investigation is conducted
through the application of linear stability theory to a suspension composed of
forward-scattering phototactic algae. The suspension is uniformly exposed to
oblique collimated flux. The bioconvection phenomenon is characterized by an
unstable disturbance mode that undergoes a transition from a stationary state
to an oscillatory state as the Taylor number varies while keeping other
parameters constant. Additionally, it is noteworthy that rotation of the system
has a substantial stabilizing effect on the suspension
Rotation and Oblique Irradiation Effects on Phototactic Algal Suspension Instability
In this study, we aim to explore the behavior of microorganisms in response
to natural lighting conditions, considering the off-normal angles at which the
sun strikes the Earth's surface. To achieve this, we investigate the effect of
oblique irradiation on a rotating medium, as this combination represents a more
realistic scenario in the natural environment. Our primary focus is on
understanding the phototactic behavior of microorganisms, which refers to their
movement towards or away from light. Under conditions of low light,
microorganisms tend to exhibit positive phototaxis, moving towards the light
source, while in intense light, they display negative phototaxis, moving away
from the light source. By studying a suspension that is illuminated by oblique
collimated flux with a constant radiation intensity applied to the top surface,
we can gain insights into how microorganisms respond to varying light
conditions and rotation. The stability analysis is conducted using linear
perturbation theory, which allows us to predict both the stationary and
oscillatory characteristics of the bio-convective instability at the onset of
bioconvection. Through this analysis, we observe that rotation plays a
significant stabilizing role in the system, while oblique irradiation has a
destabilizing effect on the suspension.Comment: arXiv admin note: substantial text overlap with arXiv:2306.1447
Thermal phototactic bioconvection in a suspension of isotropic scattering phototactic microorganism
In this investigation, we explore the thermal effects on a suspension
containing isotropic scattering phototactic microorganisms. The setup involves
illuminating the suspension with collimated irradiation from the top, coupled
with heating or cooling applied from the bottom. The governing equations
encompass the Navier-Stokes equations with the Boussinesq approximation, the
diffusion equation for motile microorganisms, and the energy equation for
temperature. Using linear perturbation theory, we conduct a comprehensive
analysis of the suspension's linear stability. The findings of this
investigation reveal that the suspension experiences increased stability as a
consequence of scattering
- …