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Hydrothermal performance of wooden beam on solid masonry with capillary-active internal insulation.
(EDP Sciences, 2024-07-16) Sukop, Lukáš; Ostrý, Milan
With the increasing requirements for the energy performance of buildings, there is a demand for internal insulation systems in buildings where it is not possible to apply an external insulation system for legislative reasons. Currently, there has been an upsurge in the development of diffusion-open insulation materials whose properties can compensate for the risks of damage to solid masonry walls insulated with traditional diffusion-closed internal insulation systems. The properties of diffusion-open systems are already well known. This paper focuses on the simulation of the thermal moisture behaviour of a detail of a timber beam embedment in a wall with capillary active thermal insulation in cold climatic conditions of Central Europe.
Monitoring of microclimatic conditions and the occurrenceof micromycetes in crawl space
(Faculty of Wood Science and Technology, 2024-07-03) Pobucká, Slávka; Kalhotka, Libor; Laichmanová, Monika; Šuhajda, Karel
Therisk of creating suitable microclimatic conditions for the growth and development of micromycetes in a crawl space is relativelyhigh. Spores of micromycetes can infiltrate theliving space through leaks in ceiling construction of the crawl space due topressure conditions.The study is focused on monitoring microclimatic conditions and the occurrence ofmicromycetes in the crawl space in the Czech Republic.Samples were taken from thecrawl space structures (ceiling structure and foundation walls) using sponges.Additionally, sedimentation methods were used to monitor the indoor microclimate (in the crawl space) and the outdoor microclimate.In the crawl space, spores of micromycetes ofthegeneraAlternaria, Aspergillus, Cladosporium, Didymella, Epicoccum, Sarocladium, Sordariaand Penicilliumwere detected. The relative humidity in the crawl space ranged from 50% to95% during the model year. In total, 6,659 hours were spent in the crawl space with a relative humidity of about 75%.
Coconut oil as Bio-based PCM: characteristics and compatibility with plastics
(Sciendo, 2023-01-14) Ostrý, Milan; Bantová, Sylva; Řezáčová, Veronika
The current use of buildings is facing an unprecedented increase in energy costs, especially in the European Union. The energy costs can be reduced by energy savings and by increased use of renewable energy represented mostly by energy converted from solar radiation. When solar energy is considered to be utilized in buildings, the mismatch between energy availability and energy demand must be solved by energy storage. This paper describes the principles of the use of latent heat thermal energy storage and the possibility of using bio-based phase change materials as heat storage media. Because the latent heat storage media undergo a change of phase during the charging and discharging, proper encapsulation is necessary. The paper presents the main findings of a study focused on the compatibility between coconut oil and selected plastics as materials of encapsulation. The compatibility of selected plastics and Coconut oil was evaluated by laboratory experiment based on the immersion of plastic samples in coconut oil and calculation of change in weight of samples within 17 weeks lasting test. The negligible weight changes were occurred for polycarbonate and polyethylene terephthalate which proves excellent compatibility with Coconut oil.
Mathematical model of mechanical testing of bone-implant (4.5 mm LCP) construct
(University of Veterinary and Pharmaceutical Sciences in Brno, 2012-09-17) Urbanová, Lucie; Blažek-Fialová, Iva; Srnec, Robert; Pěnčík, Jan; Kršek, Přemysl; Nečas, Alois
The study deals with the possibility of substituting time- and material-demanding mechanical testing of a bone defect fixation by mathematical modelling. Based on the mechanical model, a mathematical model of bone-implant construct stabilizing experimental segmental femoral bone defect (segmental ostectomy) in a miniature pig ex vivo model using 4.5 mm titanium LCP was created. It was subsequently computer-loaded by forces acting parallel to the long axis of the construct. By the effect of the acting forces the displacement vector sum of individual construct points occurred. The greatest displacement was noted in the end segments of the bone in close proximity to ostectomy and in the area of the empty central plate hole (without screw) at the level of the segmental bone defect. By studying the equivalent von Mises stress SIGMAeqv on LCP as part of the tested construct we found that the greatest changes of stress occur in the place of the empty central plate hole. The distribution of this strain was relatively symmetrical along both sides of the hole. The exceeding of the yield stress value and irreversible plastic deformations in this segment of LCP occurred at the acting of the force of 360 N. These findings are in line with the character of damage of the same construct loaded during its mechanic testing. We succeeded in creating a mathematical model of the bone-implant construct which may be further used for computer modelling of real loading of similar constructs chosen for fixation of bone defects in both experimental and clinical practice.
Study of Surface Temperature Monitoring in the Field of Buildings
(Elsevier, 2016-09-01) Slávik, Richard; Čekon, Miroslav
Surface temperature monitoring and its aspects does have not only a useful merit for thermal analysis of the buildings and their direct or indirect implementation in virtual simulations, however is equally of highly relevant use for the field of building physics as primarily those of more complex analyzing concerning on specific thermal phenomena. The measuring of surface temperatures at the building envelopes by means of well-practiced commercial temperature sensors are typically applied whose attributes can successfully be employed especially for the field of thermal building performance aspects. In addition, besides of their certain own accuracy level and final implementation for instance as an input parameter into the simulation model, typical methods of their final application related to the opaque and transparent building surfaces and their contact and non-contact modes may have the significant influence. The paper presents a representative confrontation of surface temperature monitoring of several temperature sensors as finally compared with the form of their final application on standard vertical building surfaces. Three typical ways of installation are demonstrated on opaque and transparent building component under real climate conditions applying of commercial thermocouples, digital temperature and infrared sensors. Experimental measurement assemblies are proposed and introduced with aim to point out deviating indicators in the presented area. Representative in-situ measurements are performed and final comparability of sensors based on typical methods of their final installation is presented. An obtained result, both at existing and comparing types, demonstrates its application relations to the field of buildings. In spite of that, an additional confrontation based on non-contact regime as compared with contact ones reveals a feasible option directly concerning on building surface temperature measuring.

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