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Modification of an algebraic bypass-transition model in region near the stagnation point
Straka, P. ; Příhoda, Jaromír
An algebraic model of bypass transition was applied for the numerical simulation of flow over the NACA 0012 airfoil. The system of governing equations is formed by the averaged Navier-Stokes equations closed by the k-omega turbulence model. The intemittent character of the transitional flow is described by the algebraic relation for the intermittency coefficient and by empirical relations for the onset and the length of the transition region. The constitutive relation for the turbulent velocity was modified to improve the prediction near the wall and near the leading edge. The prediction of transitional flow was carried out for the Reynolds number Re = 6x10^5 and free stream turbulence Tu = 0.3%. The agreement of numerical results with experimental data is quite good.
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A survey of attendance care for high-risk patients and patients with decubitus in choice facilities in the Czech Republic and in the Federal Republic of Germany
LANGOVÁ, Petra
Current situation: Even at the present time of the 21st century, decubitus is still considered to be a serious health complication which attacks all age groups of patients and reduce their quality of life (Boughen, 2012). Aims: The main aim of the research was to find out if the nursing treatment of patients who are at risk of pressure ulcer development or patients suffering bedsores in the Czech Republic is comparable to the treatment provided to similarly ill patients in Germany. Procedure: In order to find out necessary data, the quantitative research method was selected, during which an anonymous questionnaire both in Czech and German languages was issued and consequently submitted to general stuff nurses working at standard hospital departments. Research area: During the research survey, the general stuff nurses working in internal, surgery and rehabilitation departments in three Czech hospitals and two German hospitals. Results: The survey results showed that in the Czech Republic the Norton Scale for predicting the pressure ulcer risk is used most often, while in Germany the Braden Scale is most frequent method. The respondents, however, are equally convinced that regular inspections of skin as well as active searching for causation factors are far more suitable and helpful. Moreover, the survey revealed that the German colleagues determine the risk of developing bedsores by using the scale more frequently compared to the nurses in the Czech Republic. Significant differences in statistics were obvious in the frequency of the individual treatment interventions, especially in the areas of turning and repositioning the patient according to Bobath concept, self-dependence training, the skin assessment, as well as in the area of education. The research results showed the fact that Czech nurses statistically far more often use antiducubitus tools and materials, which are considered unsuitable or are not recommended by foreign guidelines. It was as well obvious from the research survey that the Czech nurses use compensational tools and devices when treating their patients more often compared to German hospitals. The survey results further showed that the choice of local therapeutic material used in particular working places vary considerably. While there is a more numerous utilization of materials containing silver and Tender Wet hydro-active super absorb cushions in the Czech Republic, stuff nurses in Germany prefer transparent polyurethane covers, secondary absorbing covers and polyurethane foams. Conclusions and suggestions for the practice: As far as the material availability is concerned, we are still far behind the advanced countries. However, we excel in quality as well as in the professional qualification of the nursing stuff. Prevention measures in the area of pressure ulcers are on the same level. Suggested changes and recommendations are: Suitable choice of the equipment, tools and devices. Immediately start with the self-dependence training within the rehabilitation treatment exercises and to use suitable compensational aids and utilities. It is as well advisable to create an individual body movement plan. To engage the whole multi-discipline team in the treating process for the patient. To educate the patient correctly. To ensure precise treatment documentation. Not to focus only on the assessment scale for prediction pressure ulcer risk but to carry out regular inspections of skin and search for the causation factors actively. To carry out the fading hyperaemia test in practice. Not to confuse sitting in a wheelchair and mobilisation. Verify and legalise the recommended procedures with the support of audits on pressure ulcer prevention and treatment.
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Role of local factors in formation and development of radiation fog
Potužníková, Kateřina
At the Institute of Atmospheric Physics in Prague, the 1-D atmospheric boundary layer (ABL) model has been designed to study the development of ABL structure. The model parameterisations include the atmospheric radiative transfer, the condensation process and the soil-vegetation-atmospheretransfer so that the model is able to predict the occurrence and evolution of radiation fog. The fog formation, development and dissipation are strongly influenced by local factors, such as soil and vegetation characteristics (albedo, moisture, heat conductivity, and especially vegetation height and coverage). Model simulations of the impact of different vegetation covering, soil moisture, occurrence of middle clouds and wind velocity on the ABL state and on the life cycle of radiation fog is presented.
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Kvalitativní analýza a řízení v závislosti na vstupních úodmínkách modelu protiproudé plněné kolony
Akramov, T. A. ; Jiřičný, Vladimír ; Staněk, Vladimír
In recent papers a mathematical model of the transients of the hydrodynamic of counter-current column was formulated. It was used for describing the overshoot phenomenon on the transient profiles of liquid holdup. These overshoots were observed experimentally when the bed was exposed to a sudden increase of either gas or liquid inlet velocity. Another condition for the appearance of the overshoots was that the step change in inlet velocity brings the system in proximity of the flooding point. The formulated model could under some conditions give a good description of the time behavior of the mean liquid holdup. In particular this model is capable of predicting and describing the conditions of the overshoot phenomenon after an imposed change of inlet velocity of liquid or gas. The problem now is to find out the response of the system periodical step changes in inlets velocity of gas or liquid. .
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The problem of indebtedness of households in the Czech economy (attempted comparison with the situation in Sweden)
KUBÁLEK, Jakub
The essence of my work is to acquaint the reader with the major economic and social trends in society on the issue of indebtedness of Czech households. Work, I took the form of educational and informative to readers trying to devote to the secrets of the hidden world of debt. Following the introductory words of a lot devoted to a general introduction to the issue, the factual part of the reader is exposed to a map of some sectors of the economy of Czech households and demonstrates the current situation on the dates of holy Czech Statistical Office. Specific view is focused on the structure of debt, with an analysis of the most common forms of indebtedness to be market tested. Since not draw any conclusions on the basis of certain facts which are observed close to the global profile of our population, followed by part of the global correlation and comparative. Including local comparison with selected countries, ie neighboring Slovakia and Sweden, developed a long-standing trend. The aim of this work is to find a way out of a situation and prediction of future possibilities based solely on the basis of my assumptions and forecasts compiled development.
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Numerical simulation of video-kymographic records of the vocal fold vibration
Vampola, T. ; Horáček, Jaromír
The reconstruction of the video-kymographic records from the numerical simulation of the vocal fold vibration is used for prediction of the type of vocal fold damaged. Three-dimensional (3D) finite element (FE) fully parametric model of the human larynx was developed and used for numerical simulation of stresses during vibrating vocal folds with collisions. The complex model consists of the vocal folds, arytenoids, thyroid and cricoid cartilages. The vocal fold tissue is modeled as a three layered transversal isotropic material. The results of numerical simulation of the vocal folds oscillations excited by a prescribed intraglottal aerodynamic pressure are presented. The FE contact elements are used for modelling the vocal folds collisions and the stresses in the vocal fold tissue are computed in time domain. The damaged of the ligament tissue is simulated by the modification of the modulus of elasticity. The video-kymographic records are reconstructed for health and damaged vocal folds. The results show significant dynamic stresses in all there directions (horizontal, vertical and anterior-posterior).
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Prediction of Pedestrian Movement During The Egress Situation
Hrabák, Pavel ; Ticháček, O.
The report summarizes the up-to-now progress in the application of the recursive estimation on the prediction of the pedestrian movement during the egress or evacuation situation. For these purposes a simple decision-making model has been introduced taking into account only the forward and sideways movement of pedestrians. Based on this model, a test simulation has been developed in order to test the applicability of the estimation tool to the stated decision-making model. Two main approaches of the decision process incorporated in the simulation are discussed and a modified version of the original model is presented. The report contains a manual to the used Matlab scripts and functions. The codes of needed m-files are incorporated as well.
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Extending Horizon of Finite Control Set MPC of PMSM Drive with Input LC Filter using LQ Lookahead
Šmídl, Václav ; Janouš, Š. ; Peroutka, Z.
Finite control set model predictive control (FS-MPC) has been shown to be a very effective approach to control of PMSM drives. FS-MPC is a very flexible tool since it can evaluate an arbitrary loss function. However, design of the appropriate loss function for the problem can be a challenge especially when the design input is visible only on the long horizon. An example where this problem becomes apparent is the main propulsion drive of a traction vehicle fed from a dc catenary. Specifically, the catenary voltage is subject to short circuits, fast changes, harmonics and other disturbances which can vary in very wide range. Therefore, the drive is equipped with the trolley-wire input LC filter. The filter is almost undamped by design in order to achieve maximum efficiency and the control strategy needs to secure active damping of the filter to guarantee the drive stability. While it is possible to introduce active damping terms to the loss function, it is hard to predict its properties.
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Vliv nového konkurenta na trh osobní železniční dopravy v České republice
Račková, Lucia
The aim of this work is finding out impacts of entering the railage market in Praha - Ostrava track by a new competitor. At first is described the momental state of liberalization on the railage market and then it follows by prediction of development in the forthcoming term. Practical fraction is about competition analysis on the monitored track, where is demonstrated comparison of the all carrying agents and in the closure there are educted the impacts of entering the market by the company Leo Express.
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