scholarly journals New Nonlocal Symmetries of Diffusion-Convection Equations and Their Connection with Generalized Hodograph Transformation

Symmetry ◽  
2015 ◽  
Vol 7 (4) ◽  
pp. 1751-1767 ◽  
Author(s):  
Valentyn Tychynin
Keyword(s):  
Nonlocal Symmetries ◽  
Hodograph Transformation ◽  
Diffusion Convection

scholarly journals Situations Leading to Reduced Effectiveness of Current Hand Hygiene against Infectious Mucus from Influenza Virus-Infected Patients

mSphere ◽  
2019 ◽  
Vol 4 (5) ◽  
Author(s):  
Ryohei Hirose ◽  
Takaaki Nakaya ◽  
Yuji Naito ◽  
Tomo Daidoji ◽  
Risa Bandou ◽  
...  
Keyword(s):  
Hand Hygiene ◽  
Physical Properties ◽  
Influenza A Virus ◽  
Influenza A ◽  
Ethanol Concentration ◽  
Hand Washing ◽  
Hand Rubbing ◽  
Time Required ◽  
Diffusion Convection ◽  
Low Rate

ABSTRACT Both antiseptic hand rubbing (AHR) using ethanol-based disinfectants (EBDs) and antiseptic hand washing (AHW) are important means of infection control to prevent seasonal influenza A virus (IAV) outbreaks. However, previous reports suggest a reduced efficacy of ethanol disinfection against pathogens in mucus. We aimed to elucidate the situations and mechanisms underlying the reduced efficacy of EBDs against IAV in infectious mucus. We evaluated IAV inactivation and ethanol concentration change using IAV-infected patients’ mucus (sputum). Additionally, AHR and AHW effectiveness against infectious mucus adhering to the hands and fingers was evaluated in 10 volunteers. Our clinical study showed that EBD effectiveness against IAV in mucus was extremely reduced compared to IAV in saline. IAV in mucus remained active despite 120 s of AHR; however, IAV in saline was completely inactivated within 30 s. Due to the low rate of diffusion/convection because of the physical properties of mucus as a hydrogel, the time required for the ethanol concentration to reach an IAV inactivation level and thus for EBDs to completely inactivate IAV was approximately eight times longer in mucus than in saline. On the other hand, AHR inactivated IAV in mucus within 30 s when the mucus dried completely because the hydrogel characteristics were lost. Additionally, AHW rapidly inactivated IAV. Until infectious mucus has completely dried, infectious IAV can remain on the hands and fingers, even after appropriate AHR using EBD, thereby increasing the risk of IAV transmission. We clarified the ineffectiveness of EBD use against IAV in infectious mucus. IMPORTANCE Antiseptic hand rubbing (AHR) and antiseptic hand washing (AHW) are important to prevent the spread of influenza A virus (IAV). This study elucidated the situations/mechanisms underlying the reduced efficacy of AHR against infectious mucus derived from IAV-infected individuals and indicated the weaknesses of the current hand hygiene regimens. Due to the low rate of diffusion/convection because of the physical properties of mucus as a hydrogel, the efficacy of AHR using ethanol-based disinfectant against mucus is greatly reduced until infectious mucus adhering to the hands/fingers has completely dried. If there is insufficient time before treating the next patient (i.e., if the infectious mucus is not completely dry), medical staff should be aware that effectiveness of AHR is reduced. Since AHW is effective against both dry and nondry infectious mucus, AHW should be adopted to compensate for these weaknesses of AHR.

Nonlocal Symmetries, Explicit Solutions, and Wave Structures for the Korteweg–de Vries Equation

2016 ◽  
Vol 71 (8) ◽  
pp. 735-740
Author(s):  
Zheng-Yi Ma ◽  
Jin-Xi Fei
Keyword(s):  
Vries Equation ◽  
Kdv Equation ◽  
Elliptic Functions ◽  
Group Method ◽  
Physical Interaction ◽  
Nonlocal Symmetries ◽  
Interaction Solutions ◽  
The Kdv Equation ◽  
De Vries ◽  
Exact Invariant

AbstractFrom the known Lax pair of the Korteweg–de Vries (KdV) equation, the Lie symmetry group method is successfully applied to find exact invariant solutions for the KdV equation with nonlocal symmetries by introducing two suitable auxiliary variables. Meanwhile, based on the prolonged system, the explicit analytic interaction solutions related to the hyperbolic and Jacobi elliptic functions are derived. Figures show the physical interaction between the cnoidal waves and a solitary wave.

Hodograph transformation in steady plane rotating MHD flows

1987 ◽  
Vol 43 (4) ◽  
pp. 347-353 ◽  
Author(s):  
S. N. Singh ◽  
D. D. Tripathi
Keyword(s):  
Mhd Flows ◽  
Hodograph Transformation ◽  
Steady Plane

Diffusion-convection-reaction in multicomponent mixtures

AIChE Journal ◽  
1994 ◽  
Vol 40 (10) ◽  
pp. 1665-1668 ◽  
Author(s):  
Vincenzo Guida ◽  
Raffaella Ocone ◽  
Gianni Astarita
Keyword(s):  
Multicomponent Mixtures ◽  
Diffusion Convection

Exponential nonlocal symmetries and nonnormal reduction of order

2001 ◽  
Vol 34 (47) ◽  
pp. 10109-10117 ◽  
Author(s):  
C Géronimi ◽  
M R Feix ◽  
P G L Leach
Keyword(s):  
Nonlocal Symmetries

scholarly journals NEUTRINO OSCILLATIONS AT SUPERNOVA CORE BOUNCE GENERATE THE STRONGEST GRAVITATIONAL-WAVE BURSTS

2004 ◽  
Vol 13 (07) ◽  
pp. 1297-1307
Author(s):  
HERMAN J. MOSQUERA CUESTA ◽  
KAREN FIUZA
Keyword(s):  
Gravitational Wave ◽  
Magnetic Coupling ◽  
Large Mass ◽  
Virgo Cluster ◽  
Quadrupole Moments ◽  
Cluster Of Galaxies ◽  
Weak Magnetism ◽  
New Feature ◽  
Diffusion Convection ◽  
Supernova Collapse

During the core bounce of a supernova collapse resonant active-to-active (νa→νa), as well as active-to-sterile (νa→νs) neutrino (ν) oscillations can take place. Besides, over this phase weak magnetism increases antineutrino [Formula: see text] mean free paths, and thus its luminosity. Because the oscillation feeds mass-energy into the target ν species, the large mass-squared difference between species (νa→νs) implies a huge amount of power to be given off as gravitational waves (L GWs ~1049 erg s -1), due to anisotropic but coherent ν flow over the oscillation length. This anisotropy in the ν-flux is driven by both the universal spin-rotation and the spin-magnetic coupling. The new spacetime strain estimated this way is still several orders of magnitude larger than those from ν diffusion (convection and cooling) or quadrupole moments of the neutron star matter. This new feature turns these bursts the more promising supernova gravitational-wave signal that may be detected by observatories as LIGO, VIRGO, etc., for distances far out to the VIRGO cluster of galaxies.

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