National Repository of Grey Literature 96 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Experimental investigation of homogeneous nucleation of water in various gases using an expansion chamber
Lukianova, Tetiana ; Lukianov, Mykola ; Hrubý, Jan
Nucleation is an integral part of phase transitions and plays an important role in technology. The control of nucleation in devices such as turbines, rocket and jet engines, wind tunnels, and combustion processes is key to achieving efficient, ecologically sound operation. Our paper presents information about a modernized experimental setup used for homogeneous water nucleation research.\nThe main goal of the study is an analysis of the influence of carrier gas on homogeneous nucleation.The experimental setup based on an expansion chamber has been used for research of homogeneous nucleation over several decades and has undergone various technical improvements. In the Institute of Thermomechanics, the setup was been completely disassembled and cleaned. Pressure transducers, laser, and the data acquisition system have been replaced with modern parts. After that, the chamber was assembled, and thoroughly tested and calibrated.Our investigations were carried with argon and nitrogen as carrier gases in a range of nucleation temperatures 220 – 260 K, pressure range 80-150 kPa, at several concentrations of water vapour. The results thus obtained are consistent with literature data.The findings suggest that this experimental approach is useful for homogeneous water nucleation research.
Intelligent beekeeping system
Hrubý, Jan ; Zeman, Václav (referee) ; Kiac, Martin (advisor)
The aim of this thesis is to design and develop an intelligent beekeeping system that can measure the frequency in the colony, the weight of the hive to monitor the loss or to inform the beekeeper if the bees are carrying honey. Furthermore, the security of the hive against theft is also being considered. Communication between multiple intelligent beekeeping systems is important for the functionality. This is why part of the work focuses on choosing the best possible communication, taking into consideration battery consumption and reliability. In this work, a many-to-one communication system of modules is used, which means that the number of hives can be freely expanded without affecting the functionality of the system. The resulting system is powered by a combination of battery and solar panels.
On a molecular theory of water
Jirsák, Jan ; Nezbeda, Ivo (advisor) ; Hrubý, Jan (referee) ; Kolafa, Jiří (referee) ; Jungwirth, Pavel (referee)
/ Summary Water is the most important liquid on Earth, but despite an errormous cffort put into research, it is not yet fully understood. A number of thermodyna- mic anomalies have been identified in water (e.g. the maximum of density at 4"C) and their occurrence intuitively linked to a strong intermolecular associ- ative force, i.e., hydrogen bonding. Nevertheiess, so far no rigorous molecular theory has been formulated. The present work attempts to propose and apply a rigorous statistical- -mechanical approach to water. The approach is based on recent findings that the structure of associating fluids is determined rnainly by the short-range forces (both repulsive ancl attractive). This fact enables us to apply the per- turbation theory taking a short-range model as a reference. The properties of the short-range reference model are then estimated by means of a simple, so-called primitive, model. Primitive models are anaiytically constructed to reproduce the structure of the short-range reference model keeping the in- teractions simple enough for theory. The contribution of the primitive model evaluated by Wertheim's TPT2 is used as a reference term in the perturbation expansion. The equation of state is then completed by adding dispersion and dipole-dipole correction terms. Main results of the work are as...
Influence of new cryopreservation protocol on immunogenicity and rejection of arterial allografts in rats
Hrubý, Jan ; Matia, Ivan (advisor) ; Oliverius, Martin (referee) ; Štádler, Petr (referee)
The aim of the presented experimental work was to study an acute cell and antibody- mediated immune response in recipients of abdominal aortic grafts treated by a new standardized clinical cryopreservation/slow thawing protocol used in the "Vascular graft transplant program in the Czech Republic" in a rat model. Another aim of our study was to compare the influence of two basic types of conservation protocols used in this program (cryopreservation/slow thawing protocol and cold-stored protocol) on the acute immune response after transplantation of such treated abdominal aortic grafts in rats. Cryopreserved abdominal aortic grafts were transplanted syngeneously between Lewis rats (CRYO-ISO group, cryopreservation period 172.6 days) and allogeneically between Brown-Norway and Lewis rats (CRYO-ALO group, cryopreservation period 179.3 days). The grafts were explanted on day 30 after transplantation and subsequently examined by histological and immunohistochemical methods, focusing on typical signs of acute rejection in the three basic layers of the aortic wall. We monitored the presence of endothelial cells, signs of intimal hyperplasia, tunica media thickness, the presence of necrosis and deposition of imunoglobulin class G in this layer, the number of CD4+, CD8+ and LEW MHC II+ immunocompetent cells...
Formation and transformation of atmospheric aerosol in boundary layer
Holubová Šmejkalová, Adéla ; Ždímal, Vladimír (advisor) ; Řezáčová, Daniela (referee) ; Hrubý, Jan (referee)
Title: Formation and transformation of atmospheric aerosol in boundary layer Author: Mgr. Adéla Holubová Šmejkalová Institute: Institute for Environmental Studies Supervisor: Ing. Vladimír Ždímal, Dr., Institute of Chemical Process Fundamen- tals of the CAS Training workplace: Institute of Chemical Process Fundamentals of the CAS Abstract: The experimental measurement of aerosol clusters from 1.17 nm in size was carried out from August 2016 till December 2018 at the National Atmospheric Observatory Košetice. Atmospheric conditions leading to aerosol clusters stabili- zation, fresh particles formation and particle growth were analyzed. Data of days with no new particle formation confrmed the connection between mixing layer height development and decrease of total aerosol number concentration together with lower gaseous pollutant concentrations. On the contrary, new particle for- mation process overcomes dilution of the atmosphere by increasing the number of freshly nucleated particles. Only decreasing gaseous pollutant concentrations were observed during these events. The atmospheric boundary layer was high du- ring new particle formation events that can mean enrichment of the atmosphere by other components transported by long-range transport or some transfer from the free troposphere. The measurement in...
Liquid thermal conductivity measurement of based on laminar convection
Kordík, Jozef ; Hrubý, Jan
This research report describes a device for liquid thermal conductivity measurement, which was designed within the internal project no. 902156. The principle of measurement is based on known heat transfer parameters in laminar flow regime. An experimental rig with a precise mass flow regulation and temperature measurements was designed for this purpose. The rig was tested with a pure water and based on measured quantities its thermal conductivities were obtained at several liquid temperatures. The resultant conductivities were compared with known values for pure water and a good agreement was achieved.
The measurement of the heterogeneous particles in the steam
Bartoš, Ondřej ; Hrubý, Jan ; Ždímal, Vladimír ; Kolovratník, Michal ; Jiříček, I. ; Moravec, Pavel ; Zíková, Naděžda
The aim of this extended abstract is to reveal the work done as cooperation between several institutions which was presented and published in recent years (Kolovratník, 2014). The formation of droplets in low-pressure steam turbines has a significant impact on the efficiency of energy conversion due to the strongly nonequilibrium nature of this process . The condensed water also erodes the turbine blades. A very important question is to what extent heterogeneous nucleation contributes to the phase transition process . In the case of heterogeneous nucleation , the number of droplets depends only on the number of h eterogeneous particles in the system, whereas in the case of homogeneous nucleation, the number of created droplets is determined rather by the expansion rate - in a faster expansion, greater supersaturation and more droplets are formed until the released condensation enthalpy quenches the nucleation.\nThe specific number of droplets (number of droplets per unit mass of steam) formed in the turbine can be determined by optical probes, developed first by Walters and later in the Czech Republic improved by Petr and Kolovratník. Until recently, no information was available on the relative importance of heterogeneous nucleation in forming these droplets.
Family house in Czechoslovakia after 1945
Dočekalová Klimešová, Lenka ; Hrubý, Jan (referee) ; Bacová, Andrea (referee) ; Šlapeta, Vladimír (advisor)
The main part of the doctoral thesis analyses the form of terraced housing in Czechoslovakia in the years 1945-1990. It searches for the original roots, the principles of formation and the characteristic types. The purpose was to find an answer to the question of where its values lie, because the state-controlled standardization negatively influenced the appearance of an average terraced house. The quest of seeking positive approaches the pre-war development of terraced housing and examines parallels between the groups of the 70s and the present. The subject is embedded in the wider framework of the state housing policy and its impact on the character of the new development. The thesis focuses on the period of the 70s, when family development culminat-ed. The main part analyzes three selected groups of terraced houses from the seventies. It is based on the study of available project documentations, which was made accessible by the archives of building authorities. Selected groups are considered in terms of public space and new types of terraced houses. The thesis highlights the diversity of typologi-cal forms of terraced houses of this period. The last part is devoted to the characteristics of terraced housing after 1990. The thesis summarizes the causes of the negative phenomena in suburban locations and shows the transformation of typical terraced houses. It analyses new approaches in urban development of family houses on selected groups. In the context of new concepts, it researches the solutions of public space and types of terraced houses. Finally, the thesis summarizes the transformation of the urban development of the terraced housing from 1945 to the present and proposes the other areas and problems suitable for exploration. The annexed documentary studies of three selected groups from the seventies, which were only partially published. Parts of the appendix are bar charts that evaluate the extent of the family development in individual time periods from 1945 to the present.
Modelling of Binary Nucleation in Laminar Co - Flow Tube.
Trávníčková, Tereza ; Havlica, Jaromír ; Hrubý, Jan ; Ždímal, Vladimír
Particle nucleation is one of the important phenomena encountered in both chemical engineering and environmental studies. The Laminar Co-Flow Tube (LCFT) was designed for experimental measurement of binary and ternary nucleation of mixtures of atmospheric aerosols at laboratory conditions, most often H2SO4 + H2O + amines (MEA, TEA)/terpenes (alfa-pinene, limonene). Two models were used for mathematical modeling of momentum and mass transfer in the LFDC. 2D axisymmetric CFD model and simplified 1D analytical model. A parametric study was carried out using both models and the influence of the individual simplifications of analytical model on overall behavior of the system was discussed.
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Hrubý, Jan ; MAREK, Diviš (advisor) ; HOJDA, Petr (referee)
This bachelor theses are concentrated on Sergei Parajanov, one of the most distinctive film authors from the 20th century. With his unique author approach he created films which are very distinctive with their visual poetic. Thru analysis of the means of expressions of Parajanov core works, the theses focus on aspects which are typical mainly in visual means of expression and cinematography approach. The aim of this work is to show the uniqueness of the artistic vision of Sergei Parajanov and also of the film language he uses, which is the base of the most contemporary film productions.

National Repository of Grey Literature : 96 records found   1 - 10nextend  jump to record:
See also: similar author names
3 HRUBÝ, Jiří
15 Hrubý, Jakub
1 Hrubý, Jaromír
7 Hrubý, Jaroslav
3 Hrubý, Jiří
3 Hrubý, Josef
1 Hrubý, Juraj
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