Prediction of Mixing Pattern by Using Power Number Diagram in Baffled and Unbaffled Mixing Vessels

2010 ◽  
Vol 43 (1) ◽  
pp. 46-51 ◽  
Author(s):  
Yoshihito Kato ◽  
Yutaka Tada ◽  
Yasuhiro Takeda ◽  
Naoka Atsumi ◽  
Yuichiro Nagatsu
Keyword(s):  
Power Number ◽  
Mixing Vessels

Surface Aeration Threshold in Agitated Vessels

1996 ◽  
Vol 61 (5) ◽  
pp. 681-690
Author(s):  
Kamil Wichterle ◽  
Tomáš Svěrák
Keyword(s):  
Simple Model ◽  
Liquid Surface ◽  
Power Input ◽  
Power Number ◽  
Region Analysis ◽  
Surface Aeration ◽  
Liquid Dispersion ◽  
Mixing Vessels ◽  
Number Curve

Violent agitation of liquids in mixing vessels may result in the regime of surface aeration being attained when the bubbles formed at the liquid surface enter the impeller region. Analysis of data on surface aeration for different liquids in a set of geometrically similar agitated vessels is presented. Data on the just aerated state as observed visually in transparent liquids, and data for the efficient aeration as determined from the break on the power number curve are considered. A simple model is developed for correlation of the data which enables the threshold of aeration to be predicted from the value of the recirculation number Nc = Nd (ρ/σg)1/4. The possibility of interpreting various literature data for the aeration threshold and for the power input with use of Nc is demonstrated. Similar modelling rules hold also for the correlation of beginning of the efficient liquid-liquid dispersion.

scholarly journals A comparative study to ascertain the efficacy of intravenous dexmedetomidine versus intravenous tramadol to prevent post-operative shivering after laparoscopic surgery

2019 ◽  
Vol 6 (3) ◽  
pp. 713
Author(s):  
Kishore K. ◽  
Syed Ali Aasim ◽  
Manish Kumar J.
Keyword(s):  
Laparoscopic Surgery ◽  
Side Effects ◽  
Comparative Study ◽  
General Anaesthesia ◽  
Power Number ◽  
Group Iii ◽  
Group I ◽  
Number Of Patients ◽  
Envelope Method ◽  
Level Of Significance

Background: Shivering is commonly encountered both after regional and general anaesthesia (GA) with a little higher incidence in patients receiving GA. The aim of study was to compare the effectiveness of dexmedetomidine and tramadol in decreasing postoperative shivering in patients undergoing laparoscopic surgery.Methods: Total 120 patients were included in this study. In order to get a 5% level of significance and 80% power number of patients required in each group was 40, with a total of 120 patients. Randomization of groups was done based on closed envelope method. Patients were allocated into three groups group I, II and III of 40 patients each. Patients in group I and group II were administered 0.75 μg/kg of dexmedetomidine and 1.5 mg /kg of tramadol in 100 ml NS respectively half a before extubation, while patients in group III did not receive any pharmacological intervention.Results: All three groups were comparable regarding distribution of age, gender, ASA grade and temperature at beginning and end of surgery and were non-significant.Conclusions: Dexmedetomidine seems to possess anti-shivering properties and was found to reduce the occurrence of shivering in patients undergoing general anaesthesia with minimal side effects although its anti-shivering effect was not superior to tramadol.

scholarly journals Swine ANP32A Supports Avian Influenza Virus Polymerase

2020 ◽  
Vol 94 (12) ◽  
Author(s):  
Thomas P. Peacock ◽  
Olivia C. Swann ◽  
Hamish A. Salvesen ◽  
Ecco Staller ◽  
P. Brian Leung ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Virus Replication ◽  
Mammalian Species ◽  
Gene Mutations ◽  
Influenza Viruses ◽  
Avian Influenza Viruses ◽  
2009 H1n1 ◽  
Mixing Vessels

ABSTRACT Avian influenza viruses occasionally infect and adapt to mammals, including humans. Swine are often described as “mixing vessels,” being susceptible to both avian- and human-origin viruses, which allows the emergence of novel reassortants, such as the precursor to the 2009 H1N1 pandemic. ANP32 proteins are host factors that act as influenza virus polymerase cofactors. In this study, we describe how swine ANP32A, uniquely among the mammalian ANP32 proteins tested, supports the activity of avian-origin influenza virus polymerases and avian influenza virus replication. We further show that after the swine-origin influenza virus emerged in humans and caused the 2009 pandemic, it evolved polymerase gene mutations that enabled it to more efficiently use human ANP32 proteins. We map the enhanced proviral activity of swine ANP32A to a pair of amino acids, 106 and 156, in the leucine-rich repeat and central domains and show these mutations enhance binding to influenza virus trimeric polymerase. These findings help elucidate the molecular basis for the mixing vessel trait of swine and further our understanding of the evolution and ecology of viruses in this host. IMPORTANCE Avian influenza viruses can jump from wild birds and poultry into mammalian species such as humans or swine, but they only continue to transmit if they accumulate mammalian adapting mutations. Pigs appear uniquely susceptible to both avian and human strains of influenza and are often described as virus “mixing vessels.” In this study, we describe how a host factor responsible for regulating virus replication, ANP32A, is different between swine and humans. Swine ANP32A allows a greater range of influenza viruses, specifically those from birds, to replicate. It does this by binding the virus polymerase more tightly than the human version of the protein. This work helps to explain the unique properties of swine as mixing vessels.

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