On November 15, 2012 during a working visit to China a delegation of VIAM, headed by General director of the institute, academician of RAS, professor Eugene N. Kablov visited «Wanning Site» of China Weathering Test & Research Center at the South-west research institute of engineering and applied science (SRITE).
«Wanning Site» is located on the sea-shore of south-east province Hainan and relates to a coastal type with higher corrosion aggressive activity of atmosphere. It performs complex tests of materials, structural components and articles, but also trying out of corrosion and ageing protection systems under conditions of maritime climate.
Guests from Russia got acquainted with infrastructure of the center, observed the test benches, on which specimens of metallic and non-metallic materials, articles and structures are exposed. On environmental stands of the center about 200 000 specimens are exposed under conditions of natural humidity. Average annual temperature is 24 degree, average humidity - 86%, annual amount of atmospheric precipitation -1916, 56 mm, yearly solar radiation - 5190.49MJ/m2.
Deputy Director of the South-west research institute of engineering and applied science, professor Zhang Lunwu introduced to the guests a presentation about the structure and activity of the China Weathering Testing &Research Center (CWTR), which is a branch of the South-west research institute and consolidates 7 atmospheric and 3 maritime sites for specimens exposure. Among climatic sites 5 stations, situated in different characteristic environmental zones of China should be marked out. The climatic station «Wanning Site» on the Hainan Island is the largest center for atmospheric influence testing not only in China, but in Asia as well, and the only demonstrative base of specimens, designated for investigation of maritime climate influence. A description of equipment, simulating different conditions of surroundings, loadings and effects, made by transport, was presented in the report. Methods of analysis and evaluation of the obtained testing results were also considered.
Evgeny Kablov held a meeting with deputy director of the South-west research institute of engineering and applied science Zhang Lunwu and director of the China Weathering Testing &Research Center Xiao Yong. At the negotiations the sides agreed possible directions of cooperation and in particular interchange of specimens for their exposure in different environmental zones, and also about joint development of protection systems for specific materials.
«Cooperation in the field of microbiological resistance investigation may become the item of particular importance», - summarized General director of VIAM by the results of negotiations. He emphasized, that « the average daily air temperature and high humidity on the territory of weathering center is favourable for effective growth and development of microorganisms. This problem is especially urgent for aviation hardware, which are operating under conditions of warm and humid climate ».
Rich specific variety of vegetable world of the environmental center promotes a development of different types of microorganisms – bio-destructive agent: microscopic fungi, bacteria, water-plants, actinomycetes and etc. In its turn, increasing of amount of micro-organisms – bio-destructive agents, inhabiting on the environmental station creates optimal conditions for testing materials, articles and petroleum products for micro-biological resistance.
On the part of VIAM, a leading engineer, Candidate of Biological Sciences A.A. Krivushina made a report «Investigation of microbiological resistance of materials and articles under tropical climate conditions»
Actuality of the problem of microbiological resistance of materials, articles and petroleum products as a whole was presented in the report; examples of microbiological damages of aeronautical engineering and an influence of micro-organisms on materials, articles and fuels, applied in aviation were given. It was noted, that practically all materials are subject to the influence of microorganisms. Owing to well-developed ferment systems and capacity to react quickly on changing of environment, microorganisms, especially microscopic fungi and bacteria, survive well, adapt easily and propagate themselves intensively under new, often highly extreme conditions. However, it was shown, that the most dangerous are microscopic moldy fungi. It is especially urgent for articles operating in the regions with warm humid climate.
Possible ways to increase a mycological resistance of different types of materials were considered. Among them the main ones are: insertion of antiseptics into a composition of materials, impregnation with special antiseptic solutions, application of fungi-proof coatings, addition of biocide dopes into fuel, disinfection.
General methods of testing and study of microbiological damage, carried out at FSUE”VIAM” were reported, including rapid laboratory and long-term field tests. It was noted, that, when carrying out of laboratory study, it was impossible to take into account an influence of all environmental factors, having an effect on materials under operation. Under laboratory tests only a small set of test-cultures is used, whereas in natural conditions there are hundreds of types of microorganisms, which exert influence on materials and articles. In natural conditions microorganisms are interacting continually with each other, enter into symbiotic relations or vice versa, put down a growth of one another. All these facts are reflected on the character of biological damages of materials. Therefore, together with accelerated tests in laboratory conditions, it is necessary to carry out investigations under natural conditions, where a natural contamination of materials by microorganisms is taking place.
Besides data on fungi-proofness of different materials, field tests allow to isolate microflora and expose active types of microorganisms-biodestructors, which may be used at rapid tests, to estimate a safety of protective measures. After isolation of microflora a microbiological analysis is performed – investigation of physiological properties and identification of microorganisms, isolated from specimens of materials and fuels, damaged during operation.
Press-service of VIAМ