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Effect of Microwave Radiation on the Properties of Hydrogel, Cork, Perlite, and Ceramsite
(MDPI, 2024-08-22) Průša, David; Šťastník, Stanislav; Svobodová, Kateřina; Šuhajda, Karel; Sochorová, Zuzana
The present work analyzes the effect of releasing physically bound water from hydrogel, cork, perlite, and ceramsite on materials exposed to microwave radiation and subsequently investigates possible changes in the physical properties of these materials (water absorption and thermal conductivity coefficient). The release of physically bound water from individual materials has potential practical applications in materials engineering, for example, in the internal curing of concrete, where individual aggregates could, under the influence of microwave radiation, release water into the structure of the concrete and thus further cure it. Experimental analysis was carried out with samples of the above-mentioned materials, which were first weighed and then immersed in water for 24 h. Then, they were weighed again and exposed to microwave radiation. After exposure, the samples were weighed again, left immersed in water for 24 h, and weighed again. The focus of the study was on the ability of the aggregates to release water due to microwave radiation and on the changes in the properties (water absorption, thermal conductivity coefficient) of these materials when exposed to microwave radiation. The samples were further monitored by digital microscopy for possible changes in the surface layer of the materials. The hydrogels show the highest water absorption (1000%) and the fastest water release (45 min to complete desiccation). After the release of water due to microwave radiation, their ability to absorb water is maintained. Of interest, however, is that in the case of almost complete removal of water from the soaked hydrogel, the original powdered state of the hydrogel is not obtained, but the outcome has rather a solid structure. In the case of cork, the water absorption depends on the fraction of the material.
Increase the internal surface temperature to eliminate surface condensation on the window
(EDP Sciences, 2024-07-16) Vorlíčková, Petra; Kalousek, Miloš; Šoulová, Eva
One of the most critical places in buildings in terms of physical thermal properties are windows. This is the most frequent place where the temperature drops below the dew point and surface condensation, or mould, develops. The work deals with the study of the surface temperature courses at the critical points of window glazing and connection joints and the subsequent improvement of the initial unsatisfactory condition by using a patented technology, a conductive material without further intervention in the structure. In the case of a very unsatisfactory condition, a heating resistance wire was attached to the bar, which in combination with the bar distributes the heat to a wider area. The evaluation of the surface temperature increase was performed in a steady-state thermal analysis with fixed boundary conditions and then with the influence of the flow in a room with the heater placed under the window.
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%.
Acceptance of Intelligent Ticketing Systems in Developing Countries
(Kaunas University of Technology, 2019-10-30) Shafique, Muhammad Noman; Raudellunlené, Jurgita; Davidaviciene, Vida; Pěnčík, Jan
Information communication technologies bring the revolution into all business sectors, and transportation sector is not an exception. Ticketing system has changed from traditional to intelligent, which provides information and service to the consumer. In developed countries such systems are implemented and operate successfully, while in the developing countries electronic ticketing and other similar innovative solutions face specific challenges. These challenges are related to information era and changes in consumer behaviour, caused by the development of information and communication technologies. In these new conditions the motives of consumers to choose electronic ticketing has become an extremely important factor of success. Lack of integrity of consumer behaviour and technology acceptance (electronic ticketing in particular) was identified in previous scientific research, especially taking into consideration recent conditions of developing countries. The aim of this article is to evaluate the consumers' behaviour and acceptance of intelligent systems, such as electronic ticketing, in order to identify factors, factors, influencing and encouraging the customers to use electronic ticketing systems. In this study extended technology acceptance model with trust element was used to measure the consumer behaviour. The sample for this research has been taken from China and Pakistan populations and consists of 432 participants from both countries.

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