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Basic information about a final thesis
|Type of thesis:|
Parameters affecting the quality of floor structures for cattle
Written by (author):
|prof. Ing. Štefan Mihina, PhD.|
doc. Ing. Petr Kunc, PhD.
Final thesis progress:
|Final thesis was successfully defended.|
Additional informationAdditional information about the final thesis follows. Click on the language link to display the information in the desired language.
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Title of the thesis:
Parameters affecting the quality of floor structures for cattle
|Habilitation thesis deals with floor constructions in production buildings for dairy cows, their thermophysical properties and investigating other parameters affecting the quality of the flooring. Collection of published works thematically covers issues of technical solution of individual parts of the floor structures in walking and rest areas in houses for cattle. Individual articles are focused on the sub-themes: - Floor construction affects long-term well-being and health status of the animals, their shape and material solutions, as well as the layout elements of rest and movement zones - Thermal performance of floor structures, especially evaluation of thermal resistance and thermal effusivity of floor structures in a bedding area, as well as thermal coupling coeficient of floor structures of production objects in relation to the overall conceptual space solutions and the characteristic dimension of studied subjects - Physical properties and parameters affecting the quality of floor structures - Factors affecting lying of cows, such as designing of the wear layer, situate of a lying area and cubicles and the quality of the environment - Plastic litter as a bedding material from the separated sludge slurry and the research of its physical properties for achieving of the comparable results with respect to conventional litter material. Introduction of this work contains a short description of floor structures, analysis of important design characteristics of floors and justification for further research to increase the quality of construction of livestock production buildings. Special part "Comments of published scientific papers" describes the examined designs of element floor structures and give description of measurement methods and experimental facilities. There were used following measurement methods: - Method of guarded thermal plates to determine the thermal conductivity coefficient (by STN 12 667 a STN 12 664) of rubber-foam material used for filling of mattresses and separated sludge manure, straw and sawdust as litter material with simultaneous detection of specific density in a natural wet and dried state, - Hot wire method for indirect determination of the specific heat capacity of biological wrap found on the surface of a cow-bed with a wooden or rubber pt layer, - Method of analysis of floor structures by thermal cameras and monitoring of the homogeneity of thermal layers in floors with the localization of thermal anomalies. Calculation methods (by STN 730540) respected the process of a standard for thermal values (thermal resistance, thermal effusivity and thermal coupling coeficient), software COSMOS and FEMLAB were used for the unsteady calculations. Measurement results were processed by using of Statistica. The calculation results showed that when the structural design of the floor construction ensures a cow-bed softness and flexibility of the top wear layer (straw, sawdust, shavings, rubber mats, mattresses, even wood), there are usually provided and good thermal properties. Heat effusivity of such cow-bed floors reach level of very hot and warm floors. Even the hard layer, or damaged original surfaces - when they are in rough and adhesive state, they are covered by a solid layer of biological wrap, where the animals feel well and heat effusivity is on level of the rubber surfaces. The question of floor hygiene and formability remains opened. Inorganic bedding - as sand - although creating soft cow-bed, but in the winter animals conducts away a lot of heat. There is reflected the impact with the large thermal effusivity. A clean concrete and ceramic floor surfaces fall into the so-called cold floor, but which do not suit in required softness and today they are not designed for the animals lying. If the floor is necessary insulate in terms of heat loss - at the bottom of the floor structure -- there have to be assumed with the fact that the resulting of thermal effusivity will not be improving, because the insulator is usually located deeper than the marginal value of top boundary thickness. However, the thermal resistance of the whole floor structure will increase, which can be used in cold climates with frequent protracted of frosts. There is useful in such objects the isolation with enclosing position with peripheral walls by the waist from 1.5 to 2 m wide. The other a cow-bed if they are properly solved by top wear layer maintained in a dry state, it is not necessary to isolate heat from below. Using non-stationary thermal modeling phenomena related to the process of breeding animals we can transform their technical expression by defining and wider working out of required issues. Simulations can be used for solve problems of ensuring of thermal comfort in winter, but given the constant global warming of the Earth even in summer, especially at extremely high temperatures. There was found by the modeling of sunlit of lying area, that when the animals are housed outdoors without shading of relaxation areas, there is the action of reverse heat flow from the warmed lying floor to the animal body. The exception is grassy and earthy outdoor terrain. There is greater risk of re-heat flow in the sunlit cubicles with rubber mattresses and those with deep litter than in a cow-bed with a 20 mm layer of normal litter insulator. Ideally case is the shading boxes or animals placement in a well ventilated barn with potential evaporative cooling of animals, where a cow-bed is normally by 20 °C cooler than non-shaded cubicles. There is more useful in terms of cost-effectiveness to insert the appropriate financial investment especially into top wear layer of the floor and its precision design completing. Any other repairs and replacement of floor parts are costly operational and organizational interventions.|
|Key words:||cattle, floors, thermo-technical properties|
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