scholarly journals Choice of sanitary-indicative microorganisms for the assessment of the safety of split-systems

2019 ◽  
Vol 95 (3) ◽  
pp. 296-301
Author(s):  
U. A. Rakhmanin ◽  
S. E. Shibanov ◽  
Sergey V. Kozulya

Purpose of work is a compilation of data about the microflora which colonizes a split-system, with the aim of selection of sanitary-indicative microorganisms, whose presence in the sample would indicate to the need for cleaning and disinfection of split-systems. Materials and methods. In the article there were used data of five years author’s scientific inquiry, related to the prevention of respiratory diseases, associated with the usage of a local air conditioning systems. We also use the data from the literature. Results. For selection of “indicative” microorganisms, we proposed the usage of nine criteria, each of them have numeric value from 0 to 3 points (risk for health, prevalence rate of the disease, epidemiological link, speed of split system’s colonization, difficulty of cultivation, resistance in the environment, resistance to disinfectants, frequency of detection in home air conditioning systems, frequency of detection in air conditioning systems of public buildings). After the calculation Pseudomonas aeruginosa and Staphylococcus aureus received maximal score (20 points). Therefore, these two types of bacteria are indicative microorganisms. The detection of these microorganisms in split systems will indicate to the contamination of air-conditioning system. This microflora also is a criterion of cleaning and disinfection quality - presence of these microorganisms in the samples after this process will mean that the processing of air conditioning systems was performed poorly. Conclusions. Split systems are very faster colonized by conditionally pathogenic and pathogenic microflora. To prevent the possible hazard for population’s health it is necessary to develop the normative base, according to which sanitary-and-hygienic control over the split-systems working must be carried out. Proposed criteria suggest that Pseudomonas aeruginosa and Staphylococcus aureus are indicative microorganisms, and it’s identification in the air-conditioning system would mean risk for health and necessity for cleaning and disinfection.

2013 ◽  
Vol 732-733 ◽  
pp. 605-608
Author(s):  
Can Zhou ◽  
Yu Yun Li

Established a hierarchy structure model and made a quantitative assessment of seven air-conditioning systems which are gas boiler plus electric refrigerating system、air-cooled heat pump、variable refrigerant volume air conditioning、ground-source heat pump air conditioning、centralized heat-supply plus electric refrigerating、gas direct-fired machine、energy storage on relevant professionality and indoor environment,initial investment,operating costs,operation and management,environmental impact,energy consumption.Finally we obtained an optimal scheme,which agreed with that in practice.


2012 ◽  
Vol 433-440 ◽  
pp. 1820-1827
Author(s):  
Chen Hao Yan ◽  
Hai Tao Zhang ◽  
Hua Zhang ◽  
Yan Ting Wang

Air conditioning is widely used nowadays. It brings comfortable life to us while gives some problems. Regional shortage of power supply has a great deal to do with the extensive use of air conditioner for long time. Against the background of low carbon economy, this paper choose 3 room types of 4 typical cities which have different habitable area and carry out a financial analysis of 4 types of air conditioning system(northern city has 5 types). So we’ll have a comprehensive and intuitive understand of economy of typical air conditioning system. It could help the selection of air conditioning system of different area and make good use of energy.


2019 ◽  
Vol 6 (3) ◽  
pp. 80-85
Author(s):  
Denis Igorevich Smagin ◽  
Konstantin Igorevich Starostin ◽  
Roman Sergeevich Savelyev ◽  
Anatoly Anatolyevich Satin ◽  
Anastasiya Romanovna Neveshkina ◽  
...  

One of the ways to achieve safety and comfort is to improve on-board air conditioning systems.The use of air cooling machine determines the air pressure high level at the point of selection from the aircraft engine compressor. Because of the aircraft operation in different modes and especially in the modes of small gas engines, deliberately high stages of selection have to be used for ensuring proper operation of the refrigeration machine in the modes of the aircraft small gas engines. Into force of this, most modes of aircraft operation have to throttle the pressure of the selected stage of selection, which, together with the low efficiency of the air cycle cooling system, makes the currently used air conditioning systems energy inefficient.A key feature of the architecture without air extraction from the main engines compressors is the use of electric drive compressors as a source of compressed air.A comparative analysis of competing variants of on-board air conditioning system without air extraction from engines for longrange aircraft projects was performed at the Moscow Aviation Institute (National Research University).The article deals with the main approaches to the decision-making process on the appearance of a promising aircraft on-board air conditioning system at the stage of its conceptual design and formulated the basic requirements for the structure of a complex criterion at different life cycle stages.The level of technical and technological risk, together with a larger installation weight, will require significant costs for development, testing, debugging and subsequent implementation, but at the same time on-board air conditioning system scheme without air extraction from the engines will achieve a significant increase in fuel efficiency at the level of the entire aircraft.


2019 ◽  
Vol 9 (02) ◽  
Author(s):  
Hussein A Kadhum ◽  
Thualfakar H Hasan2

The study involved the selection of two isolates from Bacillus subtilis to investigate their inhibitory activity against some bacterial pathogens. B sub-bacteria were found to have a broad spectrum against test bacteria such as Staphylococcus aureus and Pseudomonas aeruginosa. They were about 23-30 mm and less against Klebsiella sp. The sensitivity of some antibodies was tested on the test samples. The results showed that the inhibitory ability of bacterial growth in the test samples using B. subtilis extract was more effective than the antibiotics used.


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