Papers dealing with noise

Effects of noise on health

 (taken from Center of environmental hygiene of State Health Institute Prague)

Noise is every unwanted sound that is disturbing or troublesome or that affects adversely human health. Negative effects of noise on human health are partly specific ones, presented by disorders of the function of acoustic analyzer, partly non-specific ones (extra hearing), when functions of various systems of the organism are affected. These non-specific system effects appear almost in the whole range of noise intensities, frequently they are accompanied by stress reaction and impact on neurohumoral a neurovegetative regulation, biochemical reactions, sleep, higher nervous functions, such as learning and memory, impact on sensory motoric functions and coordination.
Impairment of the auditory organ, influence on cardiovascular system, sleep disturbances and adverse effects on acquiring speaking and reading skills in children are considered at present to be sufficiently established adverse health effects of noise. Limited evidence is obtained, for example, in cases of effects on hormonal and immune system, some biochemical functions, influence on placenta and development of embryo, or effects on mental health and performance of people.

Calculation and experimental verification of noise attenuation of the noise hood

Authors: RNDr. B. Madejewski,CSc., Ing. V. Kotrba, CSc.

The article describes the design, calculation and test results noise attenuation of the noise hood for large industrial compressors driven by electric motors. Predicted noise attenuation (software UTLUM) has been validated by practical measurements at the customer's place.
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Determination of acoustic power of electric machines according to ČSN and according to ISO

Authors: RNDr. B. Madejewski,CSc., Ing. Z. Gela

The article deals with comparison of differences between the methods given in ČSN 011604 and ISO 1680/1 for determination of acoustic power of electric machines. In theoretical part, and particularly in the results of the measurement it is established that the application of any of the given methods leads to the identical results. The article also draws attention to the conditions that are necessary for achieving correct results.
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APPLICATION OF THE FINITE ELEMENT METHOD IN INVESTIGATION OF DYNAMICS OF STRUCTURAL PARTS OF AN ELECTRIC MACHINE

Author: RNDr. B. Madejewski, CSc., Research Institute of Electric Machines, Brno

The author describes in an instructive way a possibility of application of the finite element method in the design of the fan cover.
Reviewed by: Doc. Ing. Věra Chalupová, CSc.
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NOISE IN ELECTRIC ROTATING MACHINES

Author: RNDr. B. Madejewski, CSc., Research Institute of Electric Machines, Brno

At present electric rotating machines are the most frequently used driving units of the machinery in industry, transport, civil engineering and agriculture. They are also commonly used in non-productive fields – in households, schools and offices.
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