Ebara sets up pump assembly plant in Vietnam

2020 ◽  
Vol 2020 (12) ◽  
pp. 2
Keyword(s):  
Author(s):  
Boris A. Sokolov ◽  
Nikolay N. Tupitsyn

The paper presents results of engineering studies and research and development efforts at RSC Energia to analyze and prove the feasibility of using the mass-produced oxygen-hydrocarbon engine 11D58M with 8.5 ton-force thrust as a basis for development of a high-performance multifunctional rocket engine with oxygen cooling and 5 ton-force thrust, which is optimal for upper stages (US), embodying a system that does not include a gas generator. The multi-functionality of the engine implies including in it additional units supporting some functions that are important for US, such as feeding propellant from US tanks to the engine after flying in zero gravity, autonomous control of the engine automatic equipment to support its firing, shutdown, adjustments during burn and emergency protection in case of off-nominal operation, as well as generating torques for controlling the US attitude and stabilizing it during coasting, etc. Replacing conventional engine chamber cooling that uses high-boiling hydrocarbon fuel with the innovative oxygen cooling makes it possible to get rid of the internal film cooling circuits and eliminate their attendant losses of fuel, while the use of the oxygen gasified in the cooling circuit of the chamber to drive the turbo pump assembly permits to design an engine that does not have a gas generator. Key words: Multifunctional rocket engine, oxygen cooling, gas-generatorless design, upper stage.


Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 830
Author(s):  
Prasangi Rajapaksha ◽  
Isoiza Ojo ◽  
Ling Yang ◽  
Ankit Pandeya ◽  
Thilini Abeywansha ◽  
...  

The RND family efflux pump AcrAB-TolC in E. coli and its homologs in other Gram-negative bacteria are major players in conferring multidrug resistance to the cells. While the structure of the pump complex has been elucidated with ever-increasing resolution through crystallography and Cryo-EM efforts, the dynamic assembly process remains poorly understood. Here, we tested the effect of overexpressing functionally defective pump components in wild type E. coli cells to probe the pump assembly process. Incorporation of a defective component is expected to reduce the efflux efficiency of the complex, leading to the so called “dominant negative” effect. Being one of the most intensively studied bacterial multidrug efflux pumps, many AcrA and AcrB mutations have been reported that disrupt efflux through different mechanisms. We examined five groups of AcrB and AcrA mutants, defective in different aspects of assembly and substrate efflux. We found that none of them demonstrated the expected dominant negative effect, even when expressed at concentrations many folds higher than their genomic counterpart. The assembly of the AcrAB-TolC complex appears to have a proof-read mechanism that effectively eliminated the formation of futile pump complex.


2010 ◽  
Vol 53 (12) ◽  
pp. 1233-1239 ◽  
Author(s):  
Robert A. Werner ◽  
Nancy Gell ◽  
Anne Hartigan ◽  
Neal Wiggermann ◽  
W. Monroe Keyserling

1997 ◽  
Author(s):  
P. U. Reusser ◽  
M. N. De Parolis ◽  
M. C. Desjean-Amould

PLoS ONE ◽  
2014 ◽  
Vol 9 (2) ◽  
pp. e89143 ◽  
Author(s):  
Wei Lu ◽  
Meng Zhong ◽  
Qian Chai ◽  
Zhaoshuai Wang ◽  
Linliang Yu ◽  
...  

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